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

using System;
using System.IO;
using Microsoft.PowerShell.EditorServices.Services.TextDocument;
using OmniSharp.Extensions.LanguageServer.Protocol;
using OmniSharp.Extensions.LanguageServer.Protocol.Models;
using Xunit;

namespace PowerShellEditorServices.Test.Language
{
    public class TokenOperationsTests
    {
        /// <summary>
        /// Helper method to create a stub script file and then call FoldableRegions
        /// </summary>
        private static FoldingReference[] GetRegions(string text)
        {
            ScriptFile scriptFile = ScriptFile.Create(
                // Use any absolute path. Even if it doesn't exist.
                DocumentUri.FromFileSystemPath(Path.Combine(Path.GetTempPath(), "TestFile.ps1")),
                text,
                Version.Parse("5.0"));

            FoldingReference[] result = TokenOperations.FoldableReferences(scriptFile.ScriptTokens).ToArray();
            // The foldable regions need to be deterministic for testing so sort the array.
            Array.Sort(result);
            return result;
        }

        /// <summary>
        /// Helper method to create FoldingReference objects with less typing
        /// </summary>
        private static FoldingReference CreateFoldingReference(int startLine, int startCharacter, int endLine, int endCharacter, FoldingRangeKind? matchKind)
        {
            return new FoldingReference
            {
                StartLine = startLine,
                StartCharacter = startCharacter,
                EndLine = endLine,
                EndCharacter = endCharacter,
                Kind = matchKind
            };
        }

        // This PowerShell script will exercise all of the
        // folding regions and regions which should not be
        // detected.  Due to file encoding this could be CLRF or LF line endings
        private const string allInOneScript =
@"#Region This should fold
<#
Nested different comment types.  This should fold
#>
#EndRegion

# region This should not fold due to whitespace
$shouldFold = $false
#    endRegion
function short-func-not-fold {};
<#
.SYNOPSIS
  This whole comment block should fold, not just the SYNOPSIS
.EXAMPLE
  This whole comment block should fold, not just the EXAMPLE
#>
function New-VSCodeShouldFold {
<#
.SYNOPSIS
  This whole comment block should fold, not just the SYNOPSIS
.EXAMPLE
  This whole comment block should fold, not just the EXAMPLE
#>
  $I = @'
herestrings should fold

'@

# This won't confuse things
Get-Command -Param @I

$I = @""
double quoted herestrings should also fold

""@

  # this won't be folded

  # This block of comments should be foldable as a single block
  # This block of comments should be foldable as a single block
  # This block of comments should be foldable as a single block

  #region This fools the indentation folding.
  Write-Host ""Hello""
    #region Nested regions should be foldable
    Write-Host ""Hello""
    # comment1
    Write-Host ""Hello""
    #endregion
    Write-Host ""Hello""
    # comment2
    Write-Host ""Hello""
    #endregion

  $c = {
    Write-Host ""Script blocks should be foldable""
  }

  # Array fools indentation folding
  $d = @(
  'should fold1',
  'should fold2'
  )
}

# Make sure contiguous comment blocks can be folded properly

# Comment Block 1
# Comment Block 1
# Comment Block 1
#region Comment Block 3
# Comment Block 2
# Comment Block 2
# Comment Block 2
$something = $true
#endregion Comment Block 3

# What about anonymous variable assignment
${this
is
valid} = 5

#RegIon This should fold due to casing
$foo = 'bar'
#EnDReGion
";
        private readonly FoldingReference[] expectedAllInOneScriptFolds = {
            CreateFoldingReference(0,   0,  4, 10, FoldingRangeKind.Region),
            CreateFoldingReference(1,   0,  3,  2, FoldingRangeKind.Comment),
            CreateFoldingReference(10,  0, 15,  2, FoldingRangeKind.Comment),
            CreateFoldingReference(16, 30, 63,  1, null),
            CreateFoldingReference(17,  0, 22,  2, FoldingRangeKind.Comment),
            CreateFoldingReference(23,  7, 26,  2, null),
            CreateFoldingReference(31,  5, 34,  2, null),
            CreateFoldingReference(38,  2, 40,  0, FoldingRangeKind.Comment),
            CreateFoldingReference(42,  2, 52, 14, FoldingRangeKind.Region),
            CreateFoldingReference(44,  4, 48, 14, FoldingRangeKind.Region),
            CreateFoldingReference(54,  7, 56,  3, null),
            CreateFoldingReference(59,  7, 62,  3, null),
            CreateFoldingReference(67,  0, 69,  0, FoldingRangeKind.Comment),
            CreateFoldingReference(70,  0, 75, 26, FoldingRangeKind.Region),
            CreateFoldingReference(71,  0, 73,  0, FoldingRangeKind.Comment),
            CreateFoldingReference(78,  0, 80,  6, null),
        };

        /// <summary>
        /// Assertion helper to compare two FoldingReference arrays.
        /// </summary>
        private static void AssertFoldingReferenceArrays(
            FoldingReference[] expected,
            FoldingReference[] actual)
        {
            for (int index = 0; index < expected.Length; index++)
            {
                Assert.Equal(expected[index], actual[index]);
            }
            Assert.Equal(expected.Length, actual.Length);
        }

        [Trait("Category", "Folding")]
        [Fact]
        public void LanguageServiceFindsFoldablRegionsWithLF()
        {
            // Remove and CR characters
            string testString = allInOneScript.Replace("\r", "");
            // Ensure that there are no CR characters in the string
            Assert.False(testString.Contains("\r\n"), "CRLF should not be present in the test string");
            FoldingReference[] result = GetRegions(testString);
            AssertFoldingReferenceArrays(expectedAllInOneScriptFolds, result);
        }

        [Trait("Category", "Folding")]
        [Fact]
        public void LanguageServiceFindsFoldablRegionsWithCRLF()
        {
            // The Foldable regions should be the same regardless of line ending type
            // Enforce CRLF line endings, if none exist
            string testString = allInOneScript;
            if (!testString.Contains("\r\n"))
            {
                testString = testString.Replace("\n", "\r\n");
            }
            // Ensure that there are CRLF characters in the string
            Assert.True(testString.IndexOf("\r\n") != -1, "CRLF should be present in the teststring");
            FoldingReference[] result = GetRegions(testString);
            AssertFoldingReferenceArrays(expectedAllInOneScriptFolds, result);
        }

        [Trait("Category", "Folding")]
        [Fact]
        public void LanguageServiceFindsFoldablRegionsWithMismatchedRegions()
        {
            const string testString =
@"#endregion should not fold - mismatched

#region This should fold
$something = 'foldable'
#endregion

#region should not fold - mismatched
";
            FoldingReference[] expectedFolds = {
                CreateFoldingReference(2, 0, 4, 10, FoldingRangeKind.Region)
            };

            FoldingReference[] result = GetRegions(testString);
            AssertFoldingReferenceArrays(expectedFolds, result);
        }

        [Trait("Category", "Folding")]
        [Fact]
        public void LanguageServiceFindsFoldablRegionsWithDuplicateRegions()
        {
            const string testString =
@"# This script causes duplicate/overlapping ranges due to the `(` and `{` characters
$AnArray = @(Get-ChildItem -Path C:\ -Include *.ps1 -File).Where({
    $_.FullName -ne 'foo'}).ForEach({
        # Do Something
})
";
            FoldingReference[] expectedFolds = {
                CreateFoldingReference(1, 64, 2, 27, null),
                CreateFoldingReference(2, 35, 4,  2, null)
            };

            FoldingReference[] result = GetRegions(testString);
            AssertFoldingReferenceArrays(expectedFolds, result);
        }

        // This tests that token matching { -> }, @{ -> } and
        // ( -> ), @( -> ) and $( -> ) does not confuse the folder
        [Trait("Category", "Folding")]
        [Fact]
        public void LanguageServiceFindsFoldablRegionsWithSameEndToken()
        {
            const string testString =
@"foreach ($1 in $2) {

    $x = @{
        'abc' = 'def'
    }
}

$y = $(
    $arr = @('1', '2'); Write-Host ($arr)
)
";
            FoldingReference[] expectedFolds = {
                CreateFoldingReference(0, 19, 5, 1, null),
                CreateFoldingReference(2,  9, 4, 5, null),
                CreateFoldingReference(7,  5, 9, 1, null)
            };

            FoldingReference[] result = GetRegions(testString);

            AssertFoldingReferenceArrays(expectedFolds, result);
        }

        // A simple PowerShell Classes test
        [Trait("Category", "Folding")]
        [Fact]
        public void LanguageServiceFindsFoldablRegionsWithClasses()
        {
            const string testString =
@"class TestClass {
    [string[]] $TestProperty = @(
        'first',
        'second',
        'third')

    [string] TestMethod() {
        return $this.TestProperty[0]
    }
}
";
            FoldingReference[] expectedFolds = {
                CreateFoldingReference(0, 16, 9,  1, null),
                CreateFoldingReference(1, 31, 4, 16, null),
                CreateFoldingReference(6, 26, 8,  5, null)
            };

            FoldingReference[] result = GetRegions(testString);

            AssertFoldingReferenceArrays(expectedFolds, result);
        }

        // This tests DSC style keywords and param blocks
        [Trait("Category", "Folding")]
        [Fact]
        public void LanguageServiceFindsFoldablRegionsWithDSC()
        {
            const string testString =
@"Configuration Example
{
    param
    (
        [Parameter()]
        [System.String[]]
        $NodeName = 'localhost',

        [Parameter(Mandatory = $true)]
        [ValidateNotNullOrEmpty()]
        [System.Management.Automation.PSCredential]
        $Credential
    )

    Import-DscResource -Module ActiveDirectoryCSDsc

    Node $AllNodes.NodeName
    {
        WindowsFeature ADCS-Cert-Authority
        {
            Ensure = 'Present'
            Name   = 'ADCS-Cert-Authority'
        }

        AdcsCertificationAuthority CertificateAuthority
        {
            IsSingleInstance = 'Yes'
            Ensure           = 'Present'
            Credential       = $Credential
            CAType           = 'EnterpriseRootCA'
            DependsOn        = '[WindowsFeature]ADCS-Cert-Authority'
        }
    }
}
";
            FoldingReference[] expectedFolds = {
                CreateFoldingReference(1,  0, 33, 1, null),
                CreateFoldingReference(3,  4, 12, 5, null),
                CreateFoldingReference(17, 4, 32, 5, null),
                CreateFoldingReference(19, 8, 22, 9, null),
                CreateFoldingReference(25, 8, 31, 9, null)
            };

            FoldingReference[] result = GetRegions(testString);

            AssertFoldingReferenceArrays(expectedFolds, result);
        }
    }
}