// Copyright (c) Microsoft Corporation.
// Licensed under the MIT License.

// expect-test updates these strings automatically
#![allow(clippy::needless_raw_string_hashes)]

use super::{CompilationState, CompilationStateUpdater};
use crate::protocol::{DiagnosticUpdate, NotebookMetadata, WorkspaceConfigurationUpdate};
use expect_test::{expect, Expect};
use qsc::{compile::ErrorKind, target::Profile, PackageType};
use qsc_project::{EntryType, JSFileEntry, Manifest, ManifestDescriptor};
use rustc_hash::FxHashMap;
use std::{cell::RefCell, fmt::Write, future::ready, rc::Rc, sync::Arc};

#[tokio::test]
async fn no_error() {
    let errors = RefCell::new(Vec::new());
    let mut updater = new_updater(&errors);

    updater
        .update_document(
            "single/foo.qs",
            1,
            "namespace Foo { @EntryPoint() operation Main() : Unit {} }",
        )
        .await;

    expect_errors(
        &errors,
        &expect![[r#"
        []
    "#]],
    );
}

#[tokio::test]
async fn clear_error() {
    let errors = RefCell::new(Vec::new());
    let mut updater = new_updater(&errors);

    updater
        .update_document("single/foo.qs", 1, "namespace {")
        .await;

    expect_errors(
        &errors,
        &expect![[r#"
            [
                (
                    "single/foo.qs",
                    Some(
                        1,
                    ),
                    [
                        Frontend(
                            Error(
                                Parse(
                                    Error(
                                        Rule(
                                            "identifier",
                                            Open(
                                                Brace,
                                            ),
                                            Span {
                                                lo: 10,
                                                hi: 11,
                                            },
                                        ),
                                    ),
                                ),
                            ),
                        ),
                    ],
                ),
            ]
        "#]],
    );

    updater
        .update_document(
            "single/foo.qs",
            2,
            "namespace Foo { @EntryPoint() operation Main() : Unit {} }",
        )
        .await;

    expect_errors(
        &errors,
        &expect![[r#"
            [
                (
                    "single/foo.qs",
                    Some(
                        2,
                    ),
                    [],
                ),
            ]
        "#]],
    );
}

#[tokio::test]
async fn close_last_doc_in_project() {
    let received_errors = RefCell::new(Vec::new());
    let mut updater = new_updater(&received_errors);

    updater
        .update_document(
            "project/src/other_file.qs",
            1,
            "namespace Foo { @EntryPoint() operation Main() : Unit {} }",
        )
        .await;
    updater
        .update_document(
            "project/src/this_file.qs",
            1,
            "/* this should not show up in the final state */ we should not see compile errors",
        )
        .await;

    updater.close_document("project/src/this_file.qs").await;
    // now there should be one compilation and one open document

    check_state_and_errors(
        &updater,
        &received_errors,
        &expect![[r#"
            {
                "project/src/other_file.qs": OpenDocument {
                    version: 1,
                    compilation: "project/qsharp.json",
                    latest_str_content: "namespace Foo { @EntryPoint() operation Main() : Unit {} }",
                },
            }
        "#]],
        &expect![[r#"
            project/qsharp.json: SourceMap {
                sources: [
                    Source {
                        name: "project/src/other_file.qs",
                        contents: "namespace Foo { @EntryPoint() operation Main() : Unit {} }",
                        offset: 0,
                    },
                    Source {
                        name: "project/src/this_file.qs",
                        contents: "// DISK CONTENTS\n namespace Foo { }",
                        offset: 59,
                    },
                ],
                entry: None,
            }
        "#]],
        &expect![[r#"
            [
                (
                    "project/src/this_file.qs",
                    Some(
                        1,
                    ),
                    [
                        Frontend(
                            Error(
                                Parse(
                                    Error(
                                        Token(
                                            Eof,
                                            ClosedBinOp(
                                                Slash,
                                            ),
                                            Span {
                                                lo: 59,
                                                hi: 60,
                                            },
                                        ),
                                    ),
                                ),
                            ),
                        ),
                    ],
                ),
                (
                    "project/src/this_file.qs",
                    None,
                    [],
                ),
            ]
        "#]],
    );
    updater.close_document("project/src/other_file.qs").await;

    // now there should be no file and no compilation
    check_state_and_errors(
        &updater,
        &received_errors,
        &expect![[r#"
            {}
        "#]],
        &expect![""],
        &expect![[r#"
            []
        "#]],
    );
}

#[tokio::test]
async fn clear_on_document_close() {
    let errors = RefCell::new(Vec::new());
    let mut updater = new_updater(&errors);

    updater
        .update_document("single/foo.qs", 1, "namespace {")
        .await;

    expect_errors(
        &errors,
        &expect![[r#"
            [
                (
                    "single/foo.qs",
                    Some(
                        1,
                    ),
                    [
                        Frontend(
                            Error(
                                Parse(
                                    Error(
                                        Rule(
                                            "identifier",
                                            Open(
                                                Brace,
                                            ),
                                            Span {
                                                lo: 10,
                                                hi: 11,
                                            },
                                        ),
                                    ),
                                ),
                            ),
                        ),
                    ],
                ),
            ]
        "#]],
    );

    updater.close_document("single/foo.qs").await;

    expect_errors(
        &errors,
        &expect![[r#"
            [
                (
                    "single/foo.qs",
                    None,
                    [],
                ),
            ]
        "#]],
    );
}

#[tokio::test]
async fn compile_error() {
    let errors = RefCell::new(Vec::new());
    let mut updater = new_updater(&errors);

    updater
        .update_document("single/foo.qs", 1, "badsyntax")
        .await;

    expect_errors(
        &errors,
        &expect![[r#"
            [
                (
                    "single/foo.qs",
                    Some(
                        1,
                    ),
                    [
                        Frontend(
                            Error(
                                Parse(
                                    Error(
                                        Token(
                                            Eof,
                                            Ident,
                                            Span {
                                                lo: 0,
                                                hi: 9,
                                            },
                                        ),
                                    ),
                                ),
                            ),
                        ),
                    ],
                ),
            ]
        "#]],
    );
}

#[tokio::test]
async fn rca_errors_are_reported_when_compilation_succeeds() {
    let errors = RefCell::new(Vec::new());
    let mut updater = new_updater(&errors);

    updater.update_configuration(WorkspaceConfigurationUpdate {
        target_profile: Some(Profile::Quantinuum),
        package_type: Some(PackageType::Lib),
    });

    updater
        .update_document("single/foo.qs", 1, "namespace Test { operation RcaCheck() : Double { use q = Qubit(); mutable x = 1.0; if MResetZ(q) == One { set x = 2.0; } x } }")
        .await;

    // we expect two errors, one for `set x = 2` and one for `x`
    expect_errors(
        &errors,
        &expect![[r#"
            [
                (
                    "single/foo.qs",
                    Some(
                        1,
                    ),
                    [
                        Pass(
                            CapabilitiesCk(
                                UseOfDynamicDouble(
                                    Span {
                                        lo: 106,
                                        hi: 117,
                                    },
                                ),
                            ),
                        ),
                        Pass(
                            CapabilitiesCk(
                                UseOfDynamicDouble(
                                    Span {
                                        lo: 121,
                                        hi: 122,
                                    },
                                ),
                            ),
                        ),
                    ],
                ),
            ]
        "#]],
    );
}

#[tokio::test]
async fn package_type_update_causes_error() {
    let errors = RefCell::new(Vec::new());
    let mut updater = new_updater(&errors);

    updater.update_configuration(WorkspaceConfigurationUpdate {
        target_profile: None,
        package_type: Some(PackageType::Lib),
    });

    updater
        .update_document(
            "single/foo.qs",
            1,
            "namespace Foo { operation Main() : Unit {} }",
        )
        .await;

    expect_errors(
        &errors,
        &expect![[r#"
            []
    "#]],
    );

    updater.update_configuration(WorkspaceConfigurationUpdate {
        target_profile: None,
        package_type: Some(PackageType::Exe),
    });

    expect_errors(
        &errors,
        &expect![[r#"
            [
                (
                    "single/foo.qs",
                    Some(
                        1,
                    ),
                    [
                        Pass(
                            EntryPoint(
                                NotFound,
                            ),
                        ),
                    ],
                ),
            ]
        "#]],
    );
}

#[tokio::test]
async fn target_profile_update_fixes_error() {
    let errors = RefCell::new(Vec::new());
    let mut updater = new_updater(&errors);

    updater.update_configuration(WorkspaceConfigurationUpdate {
        target_profile: Some(Profile::Base),
        package_type: Some(PackageType::Lib),
    });

    updater
        .update_document(
            "single/foo.qs",
            1,
            r#"namespace Foo { operation Main() : Unit { if Zero == Zero { Message("hi") } } }"#,
        )
        .await;

    expect_errors(
        &errors,
        &expect![[r#"
            [
                (
                    "single/foo.qs",
                    Some(
                        1,
                    ),
                    [
                        Pass(
                            BaseProfCk(
                                ResultComparison(
                                    Span {
                                        lo: 45,
                                        hi: 57,
                                    },
                                ),
                            ),
                        ),
                        Pass(
                            BaseProfCk(
                                ResultLiteral(
                                    Span {
                                        lo: 45,
                                        hi: 49,
                                    },
                                ),
                            ),
                        ),
                        Pass(
                            BaseProfCk(
                                ResultLiteral(
                                    Span {
                                        lo: 53,
                                        hi: 57,
                                    },
                                ),
                            ),
                        ),
                    ],
                ),
            ]
        "#]],
    );

    updater.update_configuration(WorkspaceConfigurationUpdate {
        target_profile: Some(Profile::Unrestricted),
        package_type: None,
    });

    expect_errors(
        &errors,
        &expect![[r#"
            [
                (
                    "single/foo.qs",
                    Some(
                        1,
                    ),
                    [],
                ),
            ]
        "#]],
    );
}

#[tokio::test]
async fn target_profile_update_causes_error_in_stdlib() {
    let errors = RefCell::new(Vec::new());
    let mut updater = new_updater(&errors);

    updater.update_document(
        "single/foo.qs",
        1,
        r#"namespace Foo { @EntryPoint() operation Main() : Unit { use q = Qubit(); let r = M(q); let b = Microsoft.Quantum.Convert.ResultAsBool(r); } }"#,
    ).await;

    expect_errors(
        &errors,
        &expect![[r#"
            []
        "#]],
    );

    updater.update_configuration(WorkspaceConfigurationUpdate {
        target_profile: Some(Profile::Base),
        package_type: None,
    });

    expect_errors(
        &errors,
        &expect![[r#"
            [
                (
                    "single/foo.qs",
                    Some(
                        1,
                    ),
                    [
                        Frontend(
                            Error(
                                Resolve(
                                    NotAvailable(
                                        "ResultAsBool",
                                        "Microsoft.Quantum.Convert.ResultAsBool",
                                        Span {
                                            lo: 121,
                                            hi: 133,
                                        },
                                    ),
                                ),
                            ),
                        ),
                        Frontend(
                            Error(
                                Type(
                                    Error(
                                        AmbiguousTy(
                                            Span {
                                                lo: 95,
                                                hi: 136,
                                            },
                                        ),
                                    ),
                                ),
                            ),
                        ),
                    ],
                ),
            ]
        "#]],
    );
}

#[test]
fn notebook_document_no_errors() {
    let errors = RefCell::new(Vec::new());
    let mut updater = new_updater(&errors);

    updater.update_notebook_document(
        "notebook.ipynb",
        &NotebookMetadata::default(),
        [
            ("cell1", 1, "operation Main() : Unit {}"),
            ("cell2", 1, "Main()"),
        ]
        .into_iter(),
    );

    expect_errors(
        &errors,
        &expect![[r#"
            []
        "#]],
    );
}

#[test]
fn notebook_document_errors() {
    let errors = RefCell::new(Vec::new());
    let mut updater = new_updater(&errors);

    updater.update_notebook_document(
        "notebook.ipynb",
        &NotebookMetadata::default(),
        [
            ("cell1", 1, "operation Main() : Unit {}"),
            ("cell2", 1, "Foo()"),
        ]
        .into_iter(),
    );

    expect_errors(
        &errors,
        &expect![[r#"
            [
                (
                    "cell2",
                    Some(
                        1,
                    ),
                    [
                        Frontend(
                            Error(
                                Resolve(
                                    NotFound(
                                        "Foo",
                                        Span {
                                            lo: 27,
                                            hi: 30,
                                        },
                                    ),
                                ),
                            ),
                        ),
                        Frontend(
                            Error(
                                Type(
                                    Error(
                                        AmbiguousTy(
                                            Span {
                                                lo: 27,
                                                hi: 32,
                                            },
                                        ),
                                    ),
                                ),
                            ),
                        ),
                    ],
                ),
            ]
        "#]],
    );
}

#[test]
fn notebook_document_lints() {
    let errors = RefCell::new(Vec::new());
    let mut updater = new_updater(&errors);

    updater.update_notebook_document(
        "notebook.ipynb",
        &NotebookMetadata::default(),
        [
            ("cell1", 1, "operation Foo() : Unit { let x = 4;;;; }"),
            ("cell2", 1, "operation Bar() : Unit { let y = 5 / 0; }"),
        ]
        .into_iter(),
    );

    expect_errors(
        &errors,
        &expect![[r#"
            [
                (
                    "cell1",
                    Some(
                        1,
                    ),
                    [
                        Lint(
                            Lint {
                                span: Span {
                                    lo: 35,
                                    hi: 38,
                                },
                                level: Warn,
                                message: "redundant semicolons",
                                help: "remove the redundant semicolons",
                            },
                        ),
                    ],
                ),
                (
                    "cell2",
                    Some(
                        1,
                    ),
                    [
                        Lint(
                            Lint {
                                span: Span {
                                    lo: 74,
                                    hi: 79,
                                },
                                level: Error,
                                message: "attempt to divide by zero",
                                help: "division by zero will fail at runtime",
                            },
                        ),
                    ],
                ),
            ]
        "#]],
    );
}

#[test]
fn notebook_update_remove_cell_clears_errors() {
    let errors = RefCell::new(Vec::new());
    let mut updater = new_updater(&errors);

    updater.update_notebook_document(
        "notebook.ipynb",
        &NotebookMetadata::default(),
        [
            ("cell1", 1, "operation Main() : Unit {}"),
            ("cell2", 1, "Foo()"),
        ]
        .into_iter(),
    );

    expect_errors(
        &errors,
        &expect![[r#"
            [
                (
                    "cell2",
                    Some(
                        1,
                    ),
                    [
                        Frontend(
                            Error(
                                Resolve(
                                    NotFound(
                                        "Foo",
                                        Span {
                                            lo: 27,
                                            hi: 30,
                                        },
                                    ),
                                ),
                            ),
                        ),
                        Frontend(
                            Error(
                                Type(
                                    Error(
                                        AmbiguousTy(
                                            Span {
                                                lo: 27,
                                                hi: 32,
                                            },
                                        ),
                                    ),
                                ),
                            ),
                        ),
                    ],
                ),
            ]
        "#]],
    );

    updater.update_notebook_document(
        "notebook.ipynb",
        &NotebookMetadata::default(),
        [("cell1", 1, "operation Main() : Unit {}")].into_iter(),
    );

    expect_errors(
        &errors,
        &expect![[r#"
            [
                (
                    "cell2",
                    None,
                    [],
                ),
            ]
        "#]],
    );
}

#[test]
fn close_notebook_clears_errors() {
    let errors = RefCell::new(Vec::new());
    let mut updater = new_updater(&errors);

    updater.update_notebook_document(
        "notebook.ipynb",
        &NotebookMetadata::default(),
        [
            ("cell1", 1, "operation Main() : Unit {}"),
            ("cell2", 1, "Foo()"),
        ]
        .into_iter(),
    );

    expect_errors(
        &errors,
        &expect![[r#"
            [
                (
                    "cell2",
                    Some(
                        1,
                    ),
                    [
                        Frontend(
                            Error(
                                Resolve(
                                    NotFound(
                                        "Foo",
                                        Span {
                                            lo: 27,
                                            hi: 30,
                                        },
                                    ),
                                ),
                            ),
                        ),
                        Frontend(
                            Error(
                                Type(
                                    Error(
                                        AmbiguousTy(
                                            Span {
                                                lo: 27,
                                                hi: 32,
                                            },
                                        ),
                                    ),
                                ),
                            ),
                        ),
                    ],
                ),
            ]
        "#]],
    );

    updater.close_notebook_document("notebook.ipynb");

    expect_errors(
        &errors,
        &expect![[r#"
            [
                (
                    "cell2",
                    None,
                    [],
                ),
            ]
        "#]],
    );
}

#[tokio::test]
async fn update_doc_updates_project() {
    let received_errors = RefCell::new(Vec::new());
    let mut updater = new_updater(&received_errors);

    updater
        .update_document(
            "project/src/other_file.qs",
            1,
            "namespace Foo { @EntryPoint() operation Main() : Unit {} }",
        )
        .await;
    updater
        .update_document(
            "project/src/this_file.qs",
            1,
            "namespace Foo { we should see this in the source }",
        )
        .await;

    check_state_and_errors(
        &updater,
        &received_errors,
        &expect![[r#"
            {
                "project/src/this_file.qs": OpenDocument {
                    version: 1,
                    compilation: "project/qsharp.json",
                    latest_str_content: "namespace Foo { we should see this in the source }",
                },
                "project/src/other_file.qs": OpenDocument {
                    version: 1,
                    compilation: "project/qsharp.json",
                    latest_str_content: "namespace Foo { @EntryPoint() operation Main() : Unit {} }",
                },
            }
        "#]],
        &expect![[r#"
            project/qsharp.json: SourceMap {
                sources: [
                    Source {
                        name: "project/src/other_file.qs",
                        contents: "namespace Foo { @EntryPoint() operation Main() : Unit {} }",
                        offset: 0,
                    },
                    Source {
                        name: "project/src/this_file.qs",
                        contents: "namespace Foo { we should see this in the source }",
                        offset: 59,
                    },
                ],
                entry: None,
            }
        "#]],
        &expect![[r#"
            [
                (
                    "project/src/this_file.qs",
                    Some(
                        1,
                    ),
                    [
                        Frontend(
                            Error(
                                Parse(
                                    Error(
                                        Token(
                                            Close(
                                                Brace,
                                            ),
                                            Ident,
                                            Span {
                                                lo: 75,
                                                hi: 77,
                                            },
                                        ),
                                    ),
                                ),
                            ),
                        ),
                    ],
                ),
            ]
        "#]],
    );
}

/// In this test, we:
/// open a project
/// update a buffer in the LS
/// close that buffer
/// assert that the LS no longer prioritizes that open buffer
/// over the FS
#[tokio::test]
async fn close_doc_prioritizes_fs() {
    let received_errors = RefCell::new(Vec::new());
    let mut updater = new_updater(&received_errors);

    updater
        .update_document(
            "project/src/other_file.qs",
            1,
            "namespace Foo { @EntryPoint() operation Main() : Unit {} }",
        )
        .await;
    updater
        .update_document(
            "project/src/this_file.qs",
            1,
            "/* this should not show up in the final state */ we should not see compile errors",
        )
        .await;

    updater.close_document("project/src/this_file.qs").await;

    check_state_and_errors(
        &updater,
        &received_errors,
        &expect![[r#"
            {
                "project/src/other_file.qs": OpenDocument {
                    version: 1,
                    compilation: "project/qsharp.json",
                    latest_str_content: "namespace Foo { @EntryPoint() operation Main() : Unit {} }",
                },
            }
        "#]],
        &expect![[r#"
            project/qsharp.json: SourceMap {
                sources: [
                    Source {
                        name: "project/src/other_file.qs",
                        contents: "namespace Foo { @EntryPoint() operation Main() : Unit {} }",
                        offset: 0,
                    },
                    Source {
                        name: "project/src/this_file.qs",
                        contents: "// DISK CONTENTS\n namespace Foo { }",
                        offset: 59,
                    },
                ],
                entry: None,
            }
        "#]],
        &expect![[r#"
            [
                (
                    "project/src/this_file.qs",
                    Some(
                        1,
                    ),
                    [
                        Frontend(
                            Error(
                                Parse(
                                    Error(
                                        Token(
                                            Eof,
                                            ClosedBinOp(
                                                Slash,
                                            ),
                                            Span {
                                                lo: 59,
                                                hi: 60,
                                            },
                                        ),
                                    ),
                                ),
                            ),
                        ),
                    ],
                ),
                (
                    "project/src/this_file.qs",
                    None,
                    [],
                ),
            ]
        "#]],
    );
}

#[tokio::test]
async fn delete_manifest() {
    let received_errors = RefCell::new(Vec::new());
    let mut updater = new_updater(&received_errors);

    updater
        .update_document(
            "project/src/this_file.qs",
            1,
            "// DISK CONTENTS\n namespace Foo { }",
        )
        .await;

    check_state(
        &updater,
        &expect![[r#"
            {
                "project/src/this_file.qs": OpenDocument {
                    version: 1,
                    compilation: "project/qsharp.json",
                    latest_str_content: "// DISK CONTENTS\n namespace Foo { }",
                },
            }
        "#]],
        &expect![[r#"
            project/qsharp.json: SourceMap {
                sources: [
                    Source {
                        name: "project/src/other_file.qs",
                        contents: "// DISK CONTENTS\n namespace OtherFile { operation Other() : Unit { } }",
                        offset: 0,
                    },
                    Source {
                        name: "project/src/this_file.qs",
                        contents: "// DISK CONTENTS\n namespace Foo { }",
                        offset: 71,
                    },
                ],
                entry: None,
            }
        "#]],
    );

    TEST_FS.with_borrow_mut(|fs| fs.remove("project/qsharp.json"));

    updater
        .update_document(
            "project/src/this_file.qs",
            2,
            "// DISK CONTENTS\n namespace Foo { }",
        )
        .await;

    check_state(
        &updater,
        &expect![[r#"
            {
                "project/src/this_file.qs": OpenDocument {
                    version: 2,
                    compilation: "project/src/this_file.qs",
                    latest_str_content: "// DISK CONTENTS\n namespace Foo { }",
                },
            }
        "#]],
        &expect![[r#"
            project/src/this_file.qs: SourceMap {
                sources: [
                    Source {
                        name: "project/src/this_file.qs",
                        contents: "// DISK CONTENTS\n namespace Foo { }",
                        offset: 0,
                    },
                ],
                entry: None,
            }
        "#]],
    );
}

#[tokio::test]
async fn delete_manifest_then_close() {
    let received_errors = RefCell::new(Vec::new());
    let mut updater = new_updater(&received_errors);

    updater
        .update_document(
            "project/src/this_file.qs",
            1,
            "// DISK CONTENTS\n namespace Foo { }",
        )
        .await;

    check_state(
        &updater,
        &expect![[r#"
            {
                "project/src/this_file.qs": OpenDocument {
                    version: 1,
                    compilation: "project/qsharp.json",
                    latest_str_content: "// DISK CONTENTS\n namespace Foo { }",
                },
            }
        "#]],
        &expect![[r#"
            project/qsharp.json: SourceMap {
                sources: [
                    Source {
                        name: "project/src/other_file.qs",
                        contents: "// DISK CONTENTS\n namespace OtherFile { operation Other() : Unit { } }",
                        offset: 0,
                    },
                    Source {
                        name: "project/src/this_file.qs",
                        contents: "// DISK CONTENTS\n namespace Foo { }",
                        offset: 71,
                    },
                ],
                entry: None,
            }
        "#]],
    );

    TEST_FS.with_borrow_mut(|fs| fs.remove("project/qsharp.json"));

    updater.close_document("project/src/this_file.qs").await;

    check_state(
        &updater,
        &expect![[r#"
            {}
        "#]],
        &expect![""],
    );
}

#[tokio::test]
async fn doc_switches_project() {
    let received_errors = RefCell::new(Vec::new());
    let mut updater = new_updater(&received_errors);

    updater
        .update_document("nested_projects/src/subdir/src/a.qs", 1, "namespace A {}")
        .await;

    updater
        .update_document("nested_projects/src/subdir/src/b.qs", 1, "namespace B {}")
        .await;

    check_state(
        &updater,
        &expect![[r#"
            {
                "nested_projects/src/subdir/src/a.qs": OpenDocument {
                    version: 1,
                    compilation: "nested_projects/src/subdir/qsharp.json",
                    latest_str_content: "namespace A {}",
                },
                "nested_projects/src/subdir/src/b.qs": OpenDocument {
                    version: 1,
                    compilation: "nested_projects/src/subdir/qsharp.json",
                    latest_str_content: "namespace B {}",
                },
            }
        "#]],
        &expect![[r#"
            nested_projects/src/subdir/qsharp.json: SourceMap {
                sources: [
                    Source {
                        name: "nested_projects/src/subdir/src/a.qs",
                        contents: "namespace A {}",
                        offset: 0,
                    },
                    Source {
                        name: "nested_projects/src/subdir/src/b.qs",
                        contents: "namespace B {}",
                        offset: 15,
                    },
                ],
                entry: None,
            }
        "#]],
    );

    // This is just a trick to cause the file to move between projects.
    // Deleting subdir/qsharp.json will cause subdir/a.qs to be picked up
    // by the parent directory's qsharp.json
    TEST_FS.with_borrow_mut(|fs| fs.remove("nested_projects/src/subdir/qsharp.json"));

    updater
        .update_document("nested_projects/src/subdir/src/a.qs", 2, "namespace A {}")
        .await;

    updater
        .update_document("nested_projects/src/subdir/src/b.qs", 2, "namespace B {}")
        .await;

    // the error should now be coming from the parent qsharp.json? But the document
    // is closed........
    check_state(
        &updater,
        &expect![[r#"
            {
                "nested_projects/src/subdir/src/a.qs": OpenDocument {
                    version: 2,
                    compilation: "nested_projects/qsharp.json",
                    latest_str_content: "namespace A {}",
                },
                "nested_projects/src/subdir/src/b.qs": OpenDocument {
                    version: 2,
                    compilation: "nested_projects/qsharp.json",
                    latest_str_content: "namespace B {}",
                },
            }
        "#]],
        &expect![[r#"
            nested_projects/qsharp.json: SourceMap {
                sources: [
                    Source {
                        name: "nested_projects/src/subdir/src/a.qs",
                        contents: "namespace A {}",
                        offset: 0,
                    },
                    Source {
                        name: "nested_projects/src/subdir/src/b.qs",
                        contents: "namespace B {}",
                        offset: 15,
                    },
                ],
                entry: None,
            }
        "#]],
    );
}

#[tokio::test]
async fn doc_switches_project_on_close() {
    let received_errors = RefCell::new(Vec::new());
    let mut updater = new_updater(&received_errors);

    updater
        .update_document("nested_projects/src/subdir/src/a.qs", 1, "namespace A {}")
        .await;

    updater
        .update_document("nested_projects/src/subdir/src/b.qs", 1, "namespace B {}")
        .await;

    check_state(
        &updater,
        &expect![[r#"
            {
                "nested_projects/src/subdir/src/a.qs": OpenDocument {
                    version: 1,
                    compilation: "nested_projects/src/subdir/qsharp.json",
                    latest_str_content: "namespace A {}",
                },
                "nested_projects/src/subdir/src/b.qs": OpenDocument {
                    version: 1,
                    compilation: "nested_projects/src/subdir/qsharp.json",
                    latest_str_content: "namespace B {}",
                },
            }
        "#]],
        &expect![[r#"
            nested_projects/src/subdir/qsharp.json: SourceMap {
                sources: [
                    Source {
                        name: "nested_projects/src/subdir/src/a.qs",
                        contents: "namespace A {}",
                        offset: 0,
                    },
                    Source {
                        name: "nested_projects/src/subdir/src/b.qs",
                        contents: "namespace B {}",
                        offset: 15,
                    },
                ],
                entry: None,
            }
        "#]],
    );

    // This is just a trick to cause the file to move between projects.
    // Deleting subdir/qsharp.json will cause subdir/src/a.qs to be picked up
    // by the parent directory's qsharp.json
    TEST_FS.with_borrow_mut(|fs| fs.remove("nested_projects/src/subdir/qsharp.json"));

    updater
        .close_document("nested_projects/src/subdir/src/a.qs")
        .await;

    updater
        .update_document("nested_projects/src/subdir/src/b.qs", 2, "namespace B {}")
        .await;

    check_state(
        &updater,
        &expect![[r#"
            {
                "nested_projects/src/subdir/src/b.qs": OpenDocument {
                    version: 2,
                    compilation: "nested_projects/qsharp.json",
                    latest_str_content: "namespace B {}",
                },
            }
        "#]],
        &expect![[r#"
            nested_projects/qsharp.json: SourceMap {
                sources: [
                    Source {
                        name: "nested_projects/src/subdir/src/a.qs",
                        contents: "namespace A {}",
                        offset: 0,
                    },
                    Source {
                        name: "nested_projects/src/subdir/src/b.qs",
                        contents: "namespace B {}",
                        offset: 15,
                    },
                ],
                entry: None,
            }
        "#]],
    );
}

#[tokio::test]
async fn loading_lints_config_from_manifest() {
    let this_file_qs = "namespace Foo { operation Main() : Unit { let x = 5 / 0 + (2 ^ 4); } }";
    let fs = FsNode::Dir(
        [dir(
            "project",
            [
                file(
                    "qsharp.json",
                    r#"{ "lints": [{ "lint": "divisionByZero", "level": "error" }, { "lint": "needlessParens", "level": "error" }] }"#,
                ),
                dir(
                    "src",
                    [file(
                        "this_file.qs",
                        this_file_qs,
                    )],
                ),
            ],
        )]
        .into_iter()
        .collect(),
    );

    let fs = Rc::new(RefCell::new(fs));
    let received_errors = RefCell::new(Vec::new());
    let updater = new_updater_with_file_system(&received_errors, &fs);

    // Check the LintConfig.
    check_lints_config(
        &updater,
        &expect![[r#"
            [
                LintConfig {
                    kind: Ast(
                        DivisionByZero,
                    ),
                    level: Error,
                },
                LintConfig {
                    kind: Ast(
                        NeedlessParens,
                    ),
                    level: Error,
                },
            ]"#]],
    )
    .await;
}

#[tokio::test]
async fn lints_update_after_manifest_change() {
    let this_file_qs =
        "namespace Foo { @EntryPoint() operation Main() : Unit { let x = 5 / 0 + (2 ^ 4); } }";
    let fs = FsNode::Dir(
        [dir(
            "project",
            [
                file(
                    "qsharp.json",
                    r#"{ "lints": [{ "lint": "divisionByZero", "level": "error" }, { "lint": "needlessParens", "level": "error" }] }"#,
                ),
                dir(
                    "src",
                    [file(
                        "this_file.qs",
                        this_file_qs,
                    )],
                ),
            ],
        )]
        .into_iter()
        .collect(),
    );

    let fs = Rc::new(RefCell::new(fs));
    let received_errors = RefCell::new(Vec::new());
    let mut updater = new_updater_with_file_system(&received_errors, &fs);

    // Triger a document update.
    updater
        .update_document("project/src/this_file.qs", 1, this_file_qs)
        .await;

    // Check generated lints.
    let lints: &[ErrorKind] = &received_errors.take()[0].2;
    check_lints(
        lints,
        &expect![[r#"
        [
            Lint(
                Lint {
                    span: Span {
                        lo: 72,
                        hi: 79,
                    },
                    level: Error,
                    message: "unnecessary parentheses",
                    help: "remove the extra parentheses for clarity",
                },
            ),
            Lint(
                Lint {
                    span: Span {
                        lo: 64,
                        hi: 69,
                    },
                    level: Error,
                    message: "attempt to divide by zero",
                    help: "division by zero will fail at runtime",
                },
            ),
        ]"#]],
    );

    // Modify the manifest.
    fs
        .borrow_mut()
        .write_file("project/qsharp.json", r#"{ "lints": [{ "lint": "divisionByZero", "level": "warn" }, { "lint": "needlessParens", "level": "warn" }] }"#)
        .expect("qsharp.json should exist");

    // Triger a document update
    updater
        .update_document("project/src/this_file.qs", 1, this_file_qs)
        .await;

    // Check lints again
    let lints: &[ErrorKind] = &received_errors.take()[0].2;
    check_lints(
        lints,
        &expect![[r#"
        [
            Lint(
                Lint {
                    span: Span {
                        lo: 72,
                        hi: 79,
                    },
                    level: Warn,
                    message: "unnecessary parentheses",
                    help: "remove the extra parentheses for clarity",
                },
            ),
            Lint(
                Lint {
                    span: Span {
                        lo: 64,
                        hi: 69,
                    },
                    level: Warn,
                    message: "attempt to divide by zero",
                    help: "division by zero will fail at runtime",
                },
            ),
        ]"#]],
    );
}

type ErrorInfo = (String, Option<u32>, Vec<ErrorKind>);

fn new_updater(received_errors: &RefCell<Vec<ErrorInfo>>) -> CompilationStateUpdater<'_> {
    let diagnostic_receiver = move |update: DiagnosticUpdate| {
        let mut v = received_errors.borrow_mut();

        v.push((
            update.uri.to_string(),
            update.version,
            update
                .errors
                .iter()
                .map(|e| e.error().clone())
                .collect::<Vec<_>>(),
        ));
    };

    CompilationStateUpdater::new(
        Rc::new(RefCell::new(CompilationState::default())),
        diagnostic_receiver,
        |file: String| Box::pin(ready(TEST_FS.with(|fs| fs.borrow().read_file(file)))),
        |dir_name: String| {
            Box::pin(ready(
                TEST_FS.with(|fs| fs.borrow().list_directory(dir_name)),
            ))
        },
        |file| Box::pin(ready(TEST_FS.with(|fs| fs.borrow().get_manifest(file)))),
    )
}

fn new_updater_with_file_system<'a>(
    received_errors: &'a RefCell<Vec<ErrorInfo>>,
    fs: &Rc<RefCell<FsNode>>,
) -> CompilationStateUpdater<'a> {
    let diagnostic_receiver = move |update: DiagnosticUpdate| {
        let mut v = received_errors.borrow_mut();

        v.push((
            update.uri.to_string(),
            update.version,
            update
                .errors
                .iter()
                .map(|e| e.error().clone())
                .collect::<Vec<_>>(),
        ));
    };

    let fs1 = fs.clone();
    let fs2 = fs.clone();
    let fs3 = fs.clone();

    CompilationStateUpdater::new(
        Rc::new(RefCell::new(CompilationState::default())),
        diagnostic_receiver,
        move |file: String| Box::pin(ready(fs1.borrow().read_file(file))),
        move |dir_name: String| Box::pin(ready(fs2.borrow().list_directory(dir_name))),
        move |file| Box::pin(ready(fs3.borrow().get_manifest(file))),
    )
}

fn expect_errors(errors: &RefCell<Vec<ErrorInfo>>, expected: &Expect) {
    expected.assert_debug_eq(&errors.borrow());
    // reset accumulated errors after each check
    errors.borrow_mut().clear();
}

fn assert_compilation_sources(updater: &CompilationStateUpdater<'_>, expected: &Expect) {
    let state = updater.state.try_borrow().expect("borrow should succeed");

    let compilation_sources =
        state
            .compilations
            .iter()
            .fold(String::new(), |mut output, (name, compilation)| {
                let _ = writeln!(output, "{}: {:#?}", name, compilation.0.user_unit().sources);
                output
            });
    expected.assert_eq(&compilation_sources);
}

fn assert_open_documents(updater: &CompilationStateUpdater<'_>, expected: &Expect) {
    let state = updater.state.try_borrow().expect("borrow should succeed");
    expected.assert_debug_eq(&state.open_documents);
}

fn check_state_and_errors(
    updater: &CompilationStateUpdater<'_>,
    received_errors: &RefCell<Vec<ErrorInfo>>,
    expected_open_documents: &Expect,
    expected_compilation_sources: &Expect,
    expected_errors: &Expect,
) {
    assert_open_documents(updater, expected_open_documents);
    assert_compilation_sources(updater, expected_compilation_sources);
    expect_errors(received_errors, expected_errors);
}

fn check_state(
    updater: &CompilationStateUpdater<'_>,
    expected_open_documents: &Expect,
    expected_compilation_sources: &Expect,
) {
    assert_open_documents(updater, expected_open_documents);
    assert_compilation_sources(updater, expected_compilation_sources);
}

/// Checks that the lints config is being loaded from the qsharp.json manifest
async fn check_lints_config(updater: &CompilationStateUpdater<'_>, expected_config: &Expect) {
    let manifest = updater
        .load_manifest(&"project/src/this_file.qs".into())
        .await
        .expect("manifest should exist");

    let lints_config = manifest.lints;

    expected_config.assert_eq(&format!("{lints_config:#?}"));
}

fn check_lints(lints: &[ErrorKind], expected_lints: &Expect) {
    expected_lints.assert_eq(&format!("{lints:#?}"));
}

thread_local! { static TEST_FS: RefCell<FsNode> = RefCell::new(test_fs()) }

fn test_fs() -> FsNode {
    FsNode::Dir(
        [
            dir(
                "project",
                [
                    file("qsharp.json", "{}"),
                    dir(
                        "src",
                        [
                            file(
                                "other_file.qs",
                                "// DISK CONTENTS\n namespace OtherFile { operation Other() : Unit { } }",
                            ),
                            file("this_file.qs", "// DISK CONTENTS\n namespace Foo { }"),
                        ],
                    ),
                ],
            ),
            dir(
                "nested_projects",
                [
                    file("qsharp.json", "{}"),
                    dir(
                        "src",
                        [dir(
                            "subdir",
                            [
                                file("qsharp.json", "{}"),
                                dir(
                                    "src",
                                    [
                                        file("a.qs", "namespace A {}"),
                                        file("b.qs", "namespace B {}"),
                                    ],
                                ),
                            ],
                        )],
                    ),
                ],
            ),
        ]
        .into_iter()
        .collect(),
    )
}

/// An in-memory file system implementation for the unit tests.
enum FsNode {
    Dir(FxHashMap<Arc<str>, FsNode>),
    File(Arc<str>),
}

/// A file system operation error.
#[derive(Debug)]
enum FsError {
    NotFound,
}

impl FsNode {
    fn read_file(&self, file: String) -> (Arc<str>, Arc<str>) {
        let mut curr = Some(self);

        for part in file.split('/') {
            curr = curr.and_then(|node| match node {
                FsNode::Dir(dir) => dir.get(part),
                FsNode::File(_) => None,
            });
        }

        match curr {
            Some(FsNode::File(contents)) => (file.into(), contents.clone()),
            Some(FsNode::Dir(_)) | None => (file.into(), "".into()),
        }
    }

    fn write_file(&mut self, file: &str, contents: &str) -> Result<(), FsError> {
        let mut curr = Some(self);

        for part in file.split('/') {
            curr = curr.and_then(|node| match node {
                FsNode::Dir(dir) => dir.get_mut(part),
                FsNode::File(_) => None,
            });
        }

        if let Some(FsNode::File(curr_contents)) = curr {
            *curr_contents = contents.into();
            Ok(())
        } else {
            Err(FsError::NotFound)
        }
    }

    #[allow(clippy::needless_pass_by_value)]
    fn list_directory(&self, dir_name: String) -> Vec<JSFileEntry> {
        let mut curr = Some(self);

        for part in dir_name.split('/') {
            curr = curr.and_then(|node| match node {
                FsNode::Dir(dir) => dir.get(part),
                FsNode::File(_) => None,
            });
        }

        match curr {
            Some(FsNode::Dir(dir)) => dir
                .iter()
                .map(|(name, node)| JSFileEntry {
                    name: format!("{dir_name}/{name}"),
                    r#type: match node {
                        FsNode::Dir(_) => EntryType::Folder,
                        FsNode::File(_) => EntryType::File,
                    },
                })
                .collect(),
            Some(FsNode::File(_)) | None => Vec::default(),
        }
    }

    #[allow(clippy::needless_pass_by_value)]
    fn get_manifest(&self, file: String) -> Option<ManifestDescriptor> {
        let mut curr = Some(self);
        let mut curr_path = String::new();
        let mut last_manifest_dir = None;
        let mut last_manifest = None;

        for part in file.split('/') {
            curr = curr.and_then(|node| match node {
                FsNode::Dir(dir) => {
                    if let Some(FsNode::File(manifest)) = dir.get("qsharp.json") {
                        // The semantics of get_manifest is that we only return the manifest
                        // if we've succeeded in parsing it
                        if let Ok(manifest) = serde_json::from_str::<Manifest>(manifest) {
                            last_manifest_dir = Some(curr_path.trim_end_matches('/').to_string());
                            last_manifest = Some(manifest);
                        }
                    }
                    curr_path = format!("{curr_path}{part}/");
                    dir.get(part)
                }
                FsNode::File(_) => None,
            });
        }

        match curr {
            Some(FsNode::Dir(_)) | None => None,
            Some(FsNode::File(_)) => last_manifest_dir.map(|dir| ManifestDescriptor {
                manifest: last_manifest.unwrap_or_default(),
                manifest_dir: dir.into(),
            }),
        }
    }

    fn remove(&mut self, path: &str) {
        let mut curr_parent = Some(self);
        let mut curr_name = None;

        for part in path.split('/') {
            if let Some(name) = curr_name {
                if let Some(FsNode::Dir(dir)) = curr_parent {
                    curr_parent = dir.get_mut(name);
                }
            }

            curr_name = Some(part);
        }

        let name = curr_name.expect("file name should have been set");

        match curr_parent {
            Some(FsNode::Dir(dir)) => dir.remove(name),
            Some(FsNode::File(_)) | None => panic!("path {path} does not exist"),
        };
    }
}

fn dir<const COUNT: usize>(
    name: &str,
    contents: [(Arc<str>, FsNode); COUNT],
) -> (Arc<str>, FsNode) {
    (name.into(), FsNode::Dir(contents.into_iter().collect()))
}

fn file(name: &str, contents: &str) -> (Arc<str>, FsNode) {
    (name.into(), FsNode::File(Arc::from(contents)))
}
