param(
    [string]$UnityProjectRoot = '',
    [string]$DocsRoot = ''
)

$ErrorActionPreference = 'Stop'

function Get-FullPath {
    param([string]$Path, [string]$BasePath)

    if ([string]::IsNullOrWhiteSpace($Path)) {
        return $null
    }
    if (-not [System.IO.Path]::IsPathRooted($Path)) {
        $Path = Join-Path $BasePath $Path
    }
    return [System.IO.Path]::GetFullPath($Path)
}

function Test-UnityProject {
    param([string]$Path)

    if ([string]::IsNullOrWhiteSpace($Path)) {
        return $false
    }
    return (Test-Path -LiteralPath (Join-Path $Path 'Assets')) -and
        (Test-Path -LiteralPath (Join-Path $Path 'ProjectSettings/ProjectVersion.txt'))
}

function Resolve-UnityProject {
    param([string]$ExplicitPath, [string]$DocumentationRoot)

    if (-not [string]::IsNullOrWhiteSpace($ExplicitPath)) {
        $resolved = Get-FullPath $ExplicitPath (Get-Location).Path
        if (-not (Test-UnityProject $resolved)) {
            throw "Unity project was not found: $resolved"
        }
        return $resolved
    }

    if (-not [string]::IsNullOrWhiteSpace($env:UNITY_PROJECT_ROOT)) {
        $resolved = Get-FullPath $env:UNITY_PROJECT_ROOT (Get-Location).Path
        if (-not (Test-UnityProject $resolved)) {
            throw "UNITY_PROJECT_ROOT is not a Unity project: $resolved"
        }
        return $resolved
    }

    $current = [System.IO.Path]::GetFullPath((Get-Location).Path)
    if (Test-UnityProject $current) {
        return $current
    }

    $parent = Split-Path -Parent $DocumentationRoot
    $candidates = @()
    if (Test-Path -LiteralPath $parent) {
        $directories = Get-ChildItem -LiteralPath $parent -Directory -ErrorAction SilentlyContinue
        foreach ($directory in $directories) {
            if (Test-UnityProject $directory.FullName) {
                $candidates += $directory.FullName
            }
        }
    }

    if ($candidates.Count -eq 1) {
        return [System.IO.Path]::GetFullPath($candidates[0])
    }
    if ($candidates.Count -gt 1) {
        Write-Warning 'Multiple sibling Unity projects were found. Use -UnityProjectRoot to select one.'
    }
    return $null
}

function Get-GitRoot {
    param([string]$Path)

    $result = & git -C $Path rev-parse --show-toplevel 2>$null
    if ($LASTEXITCODE -ne 0 -or [string]::IsNullOrWhiteSpace($result)) {
        return $null
    }
    return [System.IO.Path]::GetFullPath(($result | Select-Object -First 1))
}

function Get-GitChanges {
    param([string]$RepositoryRoot, [string]$RepositoryName)

    $result = @()
    if ([string]::IsNullOrWhiteSpace($RepositoryRoot)) {
        return $result
    }

    $lines = & git -C $RepositoryRoot -c core.quotepath=false status --porcelain=v1 --untracked-files=all
    if ($LASTEXITCODE -ne 0) {
        throw "Could not read git status: $RepositoryRoot"
    }

    foreach ($line in $lines) {
        if ([string]::IsNullOrWhiteSpace($line) -or $line.Length -lt 4) {
            continue
        }
        $path = $line.Substring(3).Trim()
        if ($path.Contains(' -> ')) {
            $path = ($path -split ' -> ')[-1]
        }
        $result += [pscustomobject]@{
            Repository = $RepositoryName
            Root = $RepositoryRoot
            Status = $line.Substring(0, 2)
            Path = $path.Replace('\', '/')
        }
    }
    return $result
}

function Show-Changes {
    param([string]$Title, [object[]]$Changes)

    Write-Output ""
    Write-Output "[$Title]"
    if ($Changes.Count -eq 0) {
        Write-Output '  Clean'
        return
    }
    foreach ($change in $Changes) {
        Write-Output ("  {0} {1}" -f $change.Status, $change.Path)
    }
}

function Get-MarkdownLinkFailures {
    param([string]$DocumentationRoot, [object[]]$Changes)

    $failures = @()
    $markdownChanges = $Changes | Where-Object { $_.Path -like '*.md' -and $_.Status -notmatch 'D' }
    foreach ($change in $markdownChanges) {
        $fullPath = Join-Path $DocumentationRoot $change.Path
        if (-not (Test-Path -LiteralPath $fullPath)) {
            continue
        }
        $content = [System.IO.File]::ReadAllText($fullPath, [System.Text.Encoding]::UTF8)
        $matches = [regex]::Matches($content, '!?(?:\[[^\]]*\])\((?<path>[^\)]+)\)')
        foreach ($match in $matches) {
            $link = $match.Groups['path'].Value.Trim()
            if ([string]::IsNullOrWhiteSpace($link) -or $link.StartsWith('#') -or
                $link -match '^[a-zA-Z][a-zA-Z0-9+.-]*://' -or $link -match '^mailto:') {
                continue
            }
            if ($link.StartsWith('<') -and $link.EndsWith('>')) {
                $link = $link.Substring(1, $link.Length - 2)
            }
            $pathOnly = ($link -split '#')[0]
            if ([string]::IsNullOrWhiteSpace($pathOnly)) {
                continue
            }
            $decoded = [System.Uri]::UnescapeDataString($pathOnly)
            $target = Get-FullPath $decoded (Split-Path -Parent $fullPath)
            if (-not (Test-Path -LiteralPath $target)) {
                $failures += [pscustomobject]@{
                    Source = $change.Path
                    Link = $link
                }
            }
        }
    }
    return $failures
}

$scriptRoot = Split-Path -Parent $MyInvocation.MyCommand.Path
if ([string]::IsNullOrWhiteSpace($DocsRoot)) {
    $DocsRoot = Split-Path -Parent $scriptRoot
}
$DocsRoot = Get-FullPath $DocsRoot (Get-Location).Path
$docsGitRoot = Get-GitRoot $DocsRoot
if ([string]::IsNullOrWhiteSpace($docsGitRoot)) {
    throw "Documentation git repository was not found: $DocsRoot"
}
$DocsRoot = $docsGitRoot

$resolvedUnityRoot = Resolve-UnityProject $UnityProjectRoot $DocsRoot
$unityGitRoot = $null
if (-not [string]::IsNullOrWhiteSpace($resolvedUnityRoot)) {
    $unityGitRoot = Get-GitRoot $resolvedUnityRoot
    if ([string]::IsNullOrWhiteSpace($unityGitRoot)) {
        throw "Unity project is not a git repository: $resolvedUnityRoot"
    }
}

$docsChanges = @(Get-GitChanges $DocsRoot 'UnityAI')
$unityChanges = @()
if (-not [string]::IsNullOrWhiteSpace($unityGitRoot)) {
    $unityChanges = @(Get-GitChanges $unityGitRoot (Split-Path -Leaf $resolvedUnityRoot))
}

Write-Output '[workflow-check] Read-only StrayFog workflow check'
Write-Output ("Documentation repository: {0}" -f $DocsRoot)
if ($resolvedUnityRoot) {
    Write-Output ("Unity project: {0}" -f $resolvedUnityRoot)
    $versionFile = Join-Path $resolvedUnityRoot 'ProjectSettings/ProjectVersion.txt'
    $versionLine = Get-Content -LiteralPath $versionFile -Encoding UTF8 |
        Where-Object { $_ -match '^m_EditorVersion:' } | Select-Object -First 1
    if ($versionLine) {
        Write-Output ("Unity version: {0}" -f (($versionLine -split ':', 2)[1].Trim()))
    }
}
else {
    Write-Warning 'Unity project was not found. Running documentation-only checks.'
}

Show-Changes 'UnityAI changes' $docsChanges
Show-Changes 'Unity project changes' $unityChanges

$unityPaths = @($unityChanges | ForEach-Object { $_.Path })
$copyRelationships = @(
    [pscustomobject]@{
        Name = 'CopyToHF'
        SourcePattern = '^Assets/StrayFog/Editor/CopyToX/CopyToHF/'
        TargetPattern = '^Assets/Game/GameHFScripte/CopyToHF/'
        GeneratedName = 'HF'
    },
    [pscustomobject]@{
        Name = 'CopyToGeneral'
        SourcePattern = '^Assets/StrayFog/Editor/CopyToX/CopyToGeneral/'
        TargetPattern = '^Assets/Game/GameGeneralScripte/CopyToGeneral/'
        GeneratedName = 'General'
    }
)

Write-Output ''
Write-Output '[Source and generation boundary]'
$relationshipDetected = $false
foreach ($relationship in $copyRelationships) {
    $hasSource = @($unityPaths | Where-Object {
        $_ -match $relationship.SourcePattern
    }).Count -gt 0
    $hasTarget = @($unityPaths | Where-Object {
        $_ -match $relationship.TargetPattern
    }).Count -gt 0

    if (-not $hasSource -and -not $hasTarget) {
        continue
    }
    $relationshipDetected = $true
    if ($hasSource -and -not $hasTarget) {
        Write-Warning ("{0} source changed but generated target did not change. Run CopyToX and inspect the generated diff." -f
            $relationship.Name)
    }
    elseif ($hasTarget -and -not $hasSource) {
        Write-Warning ("Generated {0} files changed without {1} source changes. Confirm that generated files were not edited directly." -f
            $relationship.GeneratedName, $relationship.Name)
    }
    else {
        Write-Output ("  Source and generated target changes were both detected for {0}." -f
            $relationship.Name)
    }
}
if (-not $relationshipDetected) {
    Write-Output '  No CopyToX source/target relationship was detected.'
}

$mappingPath = Join-Path $scriptRoot 'workflow-path-mappings.json'
$mapping = Get-Content -LiteralPath $mappingPath -Raw -Encoding UTF8 | ConvertFrom-Json
$documents = @{}
$verifications = @{}
foreach ($path in $unityPaths) {
    foreach ($entry in $mapping.mappings) {
        if ($path -match $entry.pattern) {
            $documents[$entry.document] = $true
            $verifications[$entry.verification] = $true
        }
    }
}

Write-Output ''
Write-Output '[Suggested verification]'
if ($verifications.Count -eq 0) {
    Write-Output '  No Unity verification suggestions for the current diff.'
}
else {
    foreach ($item in $verifications.Keys | Sort-Object) {
        Write-Output ("  - {0}" -f $item)
    }
}

Write-Output ''
Write-Output '[Documentation impact]'
if ($documents.Count -eq 0) {
    Write-Output '  No module document mapping matched the Unity diff.'
}
else {
    foreach ($document in $documents.Keys | Sort-Object) {
        $changed = @($docsChanges | Where-Object { $_.Path -eq $document }).Count -gt 0
        $marker = if ($changed) { 'updated' } else { 'review if long-term behavior changed' }
        Write-Output ("  - {0} ({1})" -f $document, $marker)
    }
}

$linkFailures = @(Get-MarkdownLinkFailures $DocsRoot $docsChanges)
Write-Output ''
Write-Output '[Markdown links]'
if ($linkFailures.Count -eq 0) {
    Write-Output '  Changed Markdown links are valid.'
}
else {
    foreach ($failure in $linkFailures) {
        Write-Error ("Broken link in {0}: {1}" -f $failure.Source, $failure.Link)
    }
    exit 1
}

Write-Output ''
Write-Output '[workflow-check] Completed without writing files.'
exit 0