# Changelog sync guard: require Git changes newer than this session and changelog.
$utf8 = New-Object System.Text.UTF8Encoding($false)
[Console]::InputEncoding = $utf8
[Console]::OutputEncoding = $utf8

function Write-EmptyHookResult {
    [Console]::Out.WriteLine('{}')
}

$null = [Console]::In.ReadToEnd()

# sessionStart sets this variable outside agent mode.
if ($env:CURSOR_SKIP_CHANGELOG) {
    Write-EmptyHookResult
    exit 0
}

$cursorDir = Split-Path -Parent $PSScriptRoot
$repoRoot = Split-Path -Parent $cursorDir
$changelog = Join-Path $cursorDir 'changelog\changelog-headlines.md'
$ackFile = Join-Path $cursorDir 'changelog\.changelog-ack'
$sessionMarker = Join-Path $cursorDir 'changelog\.session-start'
$scanConfigPath = Join-Path $PSScriptRoot 'changelog-scan.json'

if (-not (Test-Path -LiteralPath $changelog -PathType Leaf) -or
    -not (Test-Path -LiteralPath $scanConfigPath -PathType Leaf)) {
    Write-EmptyHookResult
    exit 0
}

if (-not (Test-Path -LiteralPath $sessionMarker -PathType Leaf)) {
    Write-EmptyHookResult
    exit 0
}

$changelogMtime = (Get-Item -LiteralPath $changelog).LastWriteTimeUtc
if ((Test-Path -LiteralPath $ackFile -PathType Leaf) -and
    (Get-Item -LiteralPath $ackFile).LastWriteTimeUtc -ge $changelogMtime) {
    Write-EmptyHookResult
    exit 0
}

$gitStatus = @(& git -C $repoRoot status --porcelain=v1 --untracked-files=all -- 2>$null)
if ($LASTEXITCODE -ne 0 -or $gitStatus.Count -eq 0) {
    Write-EmptyHookResult
    exit 0
}

try {
    $scanConfig = Get-Content -LiteralPath $scanConfigPath -Raw -Encoding UTF8 |
        ConvertFrom-Json
    if ($scanConfig.schema_version -ne 1) {
        throw "Unsupported changelog scan schema."
    }
    $includedNames = @(
        $scanConfig.included_names |
            Where-Object { $_ -is [string] -and -not [string]::IsNullOrWhiteSpace($_) }
    )
    $includedExtensions = @(
        $scanConfig.included_extensions |
            Where-Object { $_ -is [string] -and -not [string]::IsNullOrWhiteSpace($_) }
    )
    $excludedDirectoryNames = @(
        $scanConfig.excluded_directories |
            Where-Object { $_ -is [string] -and -not [string]::IsNullOrWhiteSpace($_) }
    )
} catch {
    Write-EmptyHookResult
    exit 0
}

if ($includedNames.Count -eq 0 -and $includedExtensions.Count -eq 0) {
    Write-EmptyHookResult
    exit 0
}

$comparisonMtime = $changelogMtime
$sessionMtime = (Get-Item -LiteralPath $sessionMarker).LastWriteTimeUtc
if ($sessionMtime -gt $comparisonMtime) {
    $comparisonMtime = $sessionMtime
}

$newerFile = $null
$newerRelativePath = $null
$rootItem = Get-Item -LiteralPath $repoRoot
$rootPrefix = $repoRoot.TrimEnd('\', '/') + [System.IO.Path]::DirectorySeparatorChar
$directories = New-Object 'System.Collections.Generic.Stack[System.IO.DirectoryInfo]'
$directories.Push($rootItem)

while ($directories.Count -gt 0 -and -not $newerFile) {
    $directory = $directories.Pop()
    try {
        $entries = Get-ChildItem -LiteralPath $directory.FullName -Force -ErrorAction Stop
    } catch {
        continue
    }

    foreach ($entry in $entries) {
        if ($entry.PSIsContainer) {
            $isReparsePoint = ($entry.Attributes -band [System.IO.FileAttributes]::ReparsePoint) -ne 0
            if (-not $isReparsePoint -and $excludedDirectoryNames -notcontains $entry.Name) {
                $directories.Push($entry)
            }
            continue
        }

        $isIncluded = ($includedNames -contains $entry.Name) -or
            ($includedExtensions -contains $entry.Extension)
        if ($isIncluded -and $entry.LastWriteTimeUtc -gt $comparisonMtime) {
            $relativePath = if ($entry.FullName.StartsWith(
                $rootPrefix,
                [System.StringComparison]::OrdinalIgnoreCase
            )) {
                $entry.FullName.Substring($rootPrefix.Length)
            } else {
                $entry.Name
            }
            $gitPath = $relativePath -replace '\\', '/'
            $pathStatus = @(
                & git -C $repoRoot status --porcelain=v1 --untracked-files=all -- $gitPath 2>$null
            )
            if ($LASTEXITCODE -eq 0 -and $pathStatus.Count -gt 0) {
                $newerFile = $entry
                $newerRelativePath = $relativePath
                break
            }
        }
    }
}

if ($newerFile) {
    $message = "[Hook] Project source/config has an uncommitted change newer than this session and the changelog (e.g. $newerRelativePath). Run dev-changelog Skill operation A now: add a fragment under .cursor/changelog/entries/ and rebuild the changelog views."
    $result = [ordered]@{ followup_message = $message }
    [Console]::Out.WriteLine(($result | ConvertTo-Json -Compress -Depth 3))
} else {
    Write-EmptyHookResult
}

exit 0