module FSharpChecker.FindReferences

open Xunit
open FSharp.Compiler.CodeAnalysis
open FSharp.Test.ProjectGeneration
open FSharp.Test.ProjectGeneration.Helpers

type Occurence = Definition | InType | Use

let deriveOccurence (su:FSharpSymbolUse) =
    if su.IsFromDefinition 
    then Definition
    elif su.IsFromType
    then InType
    elif su.IsFromUse
    then Use
    else failwith $"Unexpected type of occurence (for this test), symbolUse = {su}" 

/// https://github.com/dotnet/fsharp/issues/13199
let reproSourceCode = """
type MyType() = 
    member x.DoNothing(d:MyType) = ()

let a = MyType()
let b = new MyType()
a.DoNothing(b)
"""
let impFile() = { sourceFile "First" [] with ExtraSource = reproSourceCode }
let createProject() = SyntheticProject.Create(impFile())

[<Fact>]
let ``Finding usage of type via GetUsesOfSymbolInFile should also find it's constructors`` () =
    createProject().Workflow
        {        
            checkFile "First" (fun (typeCheckResult: FSharpCheckFileResults) ->
             
                let symbolUse = typeCheckResult.GetSymbolUseAtLocation(7, 11, "type MyType() =", ["MyType"]).Value
                let references = 
                    typeCheckResult.GetUsesOfSymbolInFile(symbolUse.Symbol) 
                    |> Array.sortBy (fun su -> su.Range.StartLine)
                    |> Array.map (fun su -> su.Range.StartLine, su.Range.StartColumn, su.Range.EndColumn, deriveOccurence su)

                Assert.Equal<(int*int*int*Occurence)>(
                    [| 7,5,11,Definition
                       8,25,31,InType
                       10,8,14,Use
                       11,12,18,Use
                    |],references)  )           
        }


[<Fact>]
let ``Finding usage of type via FindReference should also find it's constructors`` () =
    createProject().Workflow
        {        
            placeCursor "First" 7 11 "type MyType() =" ["MyType"]     
            findAllReferencesInFile "First" (fun (ranges:list<FSharp.Compiler.Text.range>) ->
                let ranges = 
                    ranges 
                    |> List.sortBy (fun r -> r.StartLine)
                    |> List.map (fun r -> r.StartLine, r.StartColumn, r.EndColumn)
                    |> Array.ofSeq

                Assert.Equal<(int*int*int)>(
                    [| 7,5,11 // Typedef itself
                       8,25,31 // Usage within type
                       10,8,14 // "a= ..." constructor 
                       11,12,18 // "b= ..." constructor
                    |],ranges)  )    

        }

[<Fact>]
let ``Finding usage of type via FindReference works across files`` () =
    let secondFile = { sourceFile "Second" ["First"] with ExtraSource = """
open ModuleFirst
let secondA = MyType()
let secondB = new MyType()
secondA.DoNothing(secondB)
 """}
    let original = createProject()
    let project = {original with SourceFiles = original.SourceFiles @ [secondFile]}
    project.Workflow
        {        
            placeCursor "First" 7 11 "type MyType() =" ["MyType"]     
            findAllReferencesInFile "Second" (fun (ranges:list<FSharp.Compiler.Text.range>) ->
                let ranges = 
                    ranges 
                    |> List.sortBy (fun r -> r.StartLine)
                    |> List.map (fun r -> r.StartLine, r.StartColumn, r.EndColumn)
                    |> Array.ofSeq

                Assert.Equal<(int*int*int)>(
                    [| 9,14,20 // "secondA = ..." constructor 
                       10,18,24 // "secondB = ..." constructor
                    |],ranges)  )    

        }

[<Theory>]
[<InlineData(true, true)>]
[<InlineData(true, false)>]
[<InlineData(false, true)>]
[<InlineData(false, false)>]
let ``Finding references in project`` (fastCheck, captureIdentifiersWhenParsing) =
    let size = 20

    let project =
        { SyntheticProject.Create() with
            SourceFiles = [
                sourceFile $"File%03d{0}" [] |> addSignatureFile
                for i in 1..size do
                    sourceFile $"File%03d{i}" [$"File%03d{i-1}"]
            ]
        }
        |> updateFile "File005" (addDependency "File000")
        |> updateFile "File010" (addDependency "File000")

    let checker = FSharpChecker.Create(
        enableBackgroundItemKeyStoreAndSemanticClassification = true,
        captureIdentifiersWhenParsing = captureIdentifiersWhenParsing)

    project.WorkflowWith checker {
        findAllReferencesToModuleFromFile "File000" fastCheck (expectNumberOfResults 5)
    }

[<Fact>]
let ``We find back-ticked identifiers`` () =
    SyntheticProject.Create(
        { sourceFile "First" [] with ExtraSource = "let ``foo bar`` x = x + 5" },
        { sourceFile "Second" [] with ExtraSource = "let foo x = ModuleFirst.``foo bar`` x" })
        .Workflow {
            placeCursor "Second" 6 35 "let foo x = ModuleFirst.``foo bar`` x" ["``foo bar``"]
            findAllReferences (expectToFind [
                "FileFirst.fs", 6, 4, 15
                "FileSecond.fs", 6, 12, 35
            ])
        }

[<Fact>]
let ``We find operators`` () =
    SyntheticProject.Create(
        { sourceFile "First" [] with ExtraSource = "let (++) x y = x - y" },
        { sourceFile "Second" [] with ExtraSource = """
open ModuleFirst
let foo x = x ++ 4""" })
        .Workflow {
            placeCursor "Second" 8 16 "let foo x = x ++ 4" ["++"]
            findAllReferences (expectToFind [
                "FileFirst.fs", 6, 5, 7
                "FileSecond.fs", 8, 14, 16
            ])
        }

module Parameters =

    [<Fact>]
    let ``We find function parameter in signature file`` () =
        let source = """let f param = param + 1"""
        let signature = """val f: param:int -> int"""
        SyntheticProject.Create(
            { sourceFile "Source" [] with Source = source; SignatureFile = Custom signature })
            .Workflow {
                placeCursor "Source" "param"
                findAllReferences (expectToFind [
                    "FileSource.fsi", 2, 7, 12
                    "FileSource.fs", 2, 6, 11
                    "FileSource.fs", 2, 14, 19
                ])
            }

    [<Fact>]
    let ``We find method parameter in signature file`` () =
        SyntheticProject.Create(
            { sourceFile "Source" [] with
                Source = "type MyClass() = member this.Method(methodParam) = methodParam + 1"
                SignatureFile = AutoGenerated })
            .Workflow {
                // Some race condition probably triggered by auto-generating signatures makes this
                // flaky in CI compressed metadata builds. Clearing the cache before we start fixes it ¯\_(ツ)_/¯
                clearCache
                placeCursor "Source" "methodParam"
                findAllReferences (expectToFind [
                    "FileSource.fsi", 8, 17, 28
                    "FileSource.fs", 2, 36, 47
                    "FileSource.fs", 2, 51, 62
                ])
            }

    [<Fact>]
    let ``We only find the correct parameter`` () =
        let source = """
let myFunc1 param = param + 1
let myFunc2 param = param + 2
"""
        let signature = """
val myFunc1: param: int -> int
val myFunc2: param: int -> int
"""
        SyntheticProject.Create("TupleParameterTest",
            { sourceFile "Source" [] with
                ExtraSource = source
                SignatureFile = Custom signature })
            .Workflow {
                checkFile "Source" expectOk
                placeCursor "Source" 7 17 "let myFunc1 param = param + 1" ["param"]
                findAllReferences (expectToFind [
                    "FileSource.fsi", 3, 13, 18
                    "FileSource.fs", 7, 12, 17
                    "FileSource.fs", 7, 20, 25
                ])
            }

module Attributes =

    let project() = SyntheticProject.Create(
        { sourceFile "First" [] with ExtraSource = "type MyAttribute() = inherit System.Attribute()" },
        { sourceFile "Second" [] with ExtraSource = """
open ModuleFirst
[<My>]
let foo x = 4""" },
        { sourceFile "Third" [] with ExtraSource = """
open ModuleFirst
[<MyAttribute>]
let foo x = 5""" })

    [<Fact>]
    let ``We find attributes from definition`` () =
        project().Workflow {
            placeCursor "First" 6 16 "type MyAttribute() = inherit System.Attribute()" ["MyAttribute"]
            findAllReferences (expectToFind [
                "FileFirst.fs", 6, 5, 16
                "FileSecond.fs", 8, 2, 4
                "FileThird.fs", 8, 2, 13
            ])
        }

    [<Fact>]
    let ``We find attributes from usage`` () =
        project().Workflow {
            placeCursor "Second" 8 4 "[<My>]" ["My"]
            findAllReferences (expectToFind [
                "FileFirst.fs", 6, 5, 16
                "FileSecond.fs", 8, 2, 4
                "FileThird.fs", 8, 2, 13
            ])
        }

    [<Fact>]
    let ``We find attributes from usage with Attribute suffix`` () =
        project().Workflow {
            placeCursor "Third" 8 13 "[<MyAttribute>]" ["MyAttribute"]
            findAllReferences (expectToFind [
                "FileFirst.fs", 6, 5, 16
                "FileSecond.fs", 8, 2, 4
                "FileThird.fs", 8, 2, 13
            ])
        }

[<Fact>]
let ``We find values of a type that has been aliased`` () =

    let project = SyntheticProject.Create(
        { sourceFile "First" [] with
            ExtraSource = "type MyInt = int32\n" +
                          "let myNum = 7"
            SignatureFile = Custom ("type MyInt = int32\n" +
                                    "val myNum: MyInt") },
        { sourceFile "Second" [] with
            ExtraSource = "let goo x = ModuleFirst.myNum + x"})

    project.Workflow {
        placeCursor "First" "myNum"
        findAllReferences (expectToFind [
            "FileFirst.fs", 7, 4, 9
            "FileFirst.fsi", 3, 4, 9
            "FileSecond.fs", 6, 12, 29
        ])
    }

[<Fact>]
let ``We don't find type aliases for a type`` () =

    let source = """
type MyType =
    member _.foo = "boo"
    member x.this : mytype = x
and mytype = MyType
"""

    let fileName, options, checker = singleFileChecker source

    let symbolUse = getSymbolUse fileName source "MyType" options checker |> Async.RunSynchronously

    checker.FindBackgroundReferencesInFile(fileName, options, symbolUse.Symbol, fastCheck = true)
    |> Async.RunSynchronously
    |> expectToFind [
        fileName, 2, 5, 11
        fileName, 5, 13, 19
    ]

/// https://github.com/dotnet/fsharp/issues/14396
[<Fact>]
let ``itemKeyStore disappearance`` () =

    let source = """
type MyType() = class end

let x = MyType()
"""
    SyntheticProject.Create(
        { sourceFile "Program" [] with
            SignatureFile = Custom ""
            Source = source } ).Workflow {

        placeCursor "Program" "MyType"

        findAllReferences (expectToFind [
            "FileProgram.fs", 3, 5, 11
            "FileProgram.fs", 5, 8, 14
        ])

        updateFile "Program" (fun f -> { f with Source = "\n" + f.Source })
        saveFile "Program"

        findAllReferences (expectToFind [
            "FileProgram.fs", 4, 5, 11
            "FileProgram.fs", 6, 8, 14
        ])
    }

[<Fact>]
let ``itemKeyStore disappearance with live buffers`` () =

    let source = """
type MyType() = class end

let x = MyType()
"""
    let project = SyntheticProject.Create(
        { sourceFile "Program" [] with
            SignatureFile = Custom ""
            Source = source } )

    ProjectWorkflowBuilder(project, useGetSource = true, useChangeNotifications = true) {

        placeCursor "Program" "MyType"

        findAllReferences (expectToFind [
            "FileProgram.fs", 3, 5, 11
            "FileProgram.fs", 5, 8, 14
        ])

        updateFile "Program" (fun f -> { f with Source = "\n" + f.Source })

        placeCursor "Program" "MyType"

        findAllReferences (expectToFind [
            "FileProgram.fs", 4, 5, 11
            "FileProgram.fs", 6, 8, 14
        ])
    }


module ActivePatterns =

    /// https://github.com/dotnet/fsharp/issues/14206
    [<Fact>]
    let ``Finding references to an active pattern case shouldn't find other cases`` () =
        let source = """
let (|Even|Odd|) v =
    if v % 2 = 0 then Even else Odd
match 2 with
| Even -> ()
| Odd -> ()
"""
        let fileName, options, checker = singleFileChecker source

        let symbolUse = getSymbolUse fileName source "Even" options checker |> Async.RunSynchronously

        checker.FindBackgroundReferencesInFile(fileName, options, symbolUse.Symbol, fastCheck = true)
        |> Async.RunSynchronously
        |> expectToFind [
            fileName, 2, 6, 10
            fileName, 3, 22, 26
            fileName, 5, 2, 6
        ]

    [<Fact>]
    let ``We don't find references to cases from other active patterns with the same name`` () =

        let source = """
module One =

    let (|Even|Odd|) v =
        if v % 2 = 0 then Even else Odd
    match 2 with
    | Even -> ()
    | Odd -> ()

module Two =

    let (|Even|Steven|) v =
        if v % 3 = 0 then Steven else Even
    match 2 with
    | Even -> ()
    | Steven -> ()
"""

        let fileName, options, checker = singleFileChecker source

        let symbolUse = getSymbolUse fileName source "Even" options checker |> Async.RunSynchronously

        checker.FindBackgroundReferencesInFile(fileName, options, symbolUse.Symbol, fastCheck = true)
        |> Async.RunSynchronously
        |> expectToFind [
            fileName, 4, 10, 14
            fileName, 5, 26, 30
            fileName, 7, 6, 10
        ]

    [<Fact>]
    let ``We don't find references to cases the same active pattern defined in a different file`` () =

        let source = """
let (|Even|Odd|) v =
    if v % 2 = 0 then Even else Odd
match 2 with
| Even -> ()
| Odd -> ()
"""
        SyntheticProject.Create(
            { sourceFile "First" [] with Source = source },
            { sourceFile "Second" [] with Source = source }
        ).Workflow {
            placeCursor "First" "Even"
            findAllReferences (expectToFind [
                "FileFirst.fs", 3, 6, 10
                "FileFirst.fs", 4, 22, 26
                "FileFirst.fs", 6, 2, 6
            ])
        }

    [<Fact>]
    let ``We find active patterns in other files when there are signature files`` () =

        SyntheticProject.Create(
            { sourceFile "First" [] with
                Source = "let (|Even|Odd|) v = if v % 2 = 0 then Even else Odd"
                SignatureFile = AutoGenerated },
            { sourceFile "Second" [] with
                Source = """
open ModuleFirst
match 2 with | Even -> () | Odd -> ()
""" }
        ).Workflow {
            placeCursor "Second" "Even"
            findAllReferences (expectToFind [
                "FileFirst.fs", 2, 6, 10
                "FileFirst.fs", 2, 39, 43
                "FileSecond.fs", 4, 15, 19
            ])
        }

    /// Bug: https://github.com/dotnet/fsharp/issues/14969
    [<Fact>]
    let ``We DON'T find active patterns in signature files`` () =
        SyntheticProject.Create(
            { sourceFile "First" [] with
                Source = "let (|Even|Odd|) v = if v % 2 = 0 then Even else Odd"
                SignatureFile = AutoGenerated }
        ).Workflow {
            placeCursor "First" "Even"
            findAllReferences (expectToFind [
                "FileFirst.fs", 2, 6, 10
                "FileFirst.fs", 2, 39, 43
                //"FileFirst.fsi", 4, 6, 10 <-- this should also be found
            ])
        }