# PostToolUse hook for Edit|Write: runs dotnet format on the C# file Claude just edited.
# Claude Code sends the tool call as JSON on stdin; tool_input.file_path is absolute.
try {
    $stdin = New-Object System.IO.StreamReader([Console]::OpenStandardInput(), (New-Object System.Text.UTF8Encoding $false))
    $raw = $stdin.ReadToEnd()
    $call = $raw | ConvertFrom-Json -ErrorAction Stop
} catch {
    [Console]::Error.WriteLine("format-cs.ps1 could not read the hook input: $($_.Exception.Message)")
    exit 1
}
$root = if ($env:CLAUDE_PROJECT_DIR) { $env:CLAUDE_PROJECT_DIR } else { $call.cwd }
$root = [IO.Path]::GetFullPath($root).TrimEnd('\')

# Keep what the hook received and a one-line summary (successful hooks show nothing in the transcript).
$logDir = Join-Path $root '.claude\hooks\logs'
New-Item -ItemType Directory -Force -Path $logDir | Out-Null
Add-Content -Path (Join-Path $logDir 'hook-input.jsonl') -Value $raw.Trim() -Encoding UTF8
function Write-HookLog([string]$text) {
    $since = [math]::Round(((Get-Date) - (Get-Process -Id $PID).StartTime).TotalSeconds, 2)
    $codePage = try { [Console]::InputEncoding.CodePage } catch { 'none' }
    $line = '{0}  PostToolUse  format-cs.ps1  {1} {2} cp={3}  {4}  process_s={5}' -f (Get-Date).ToString('o'),
        (Get-Process -Id $PID).Path, $PSVersionTable.PSVersion, $codePage, $text, $since
    Add-Content -Path (Join-Path $logDir 'hooks.log') -Value $line -Encoding UTF8
}

if (-not $call.tool_input.file_path) { exit 0 }
$file = [IO.Path]::GetFullPath("$($call.tool_input.file_path)")
if (-not $file.EndsWith('.cs', 'OrdinalIgnoreCase') -or -not $file.StartsWith($root + '\', 'OrdinalIgnoreCase')) {
    Write-HookLog "tool=$($call.tool_name) skipped $($file.Replace($root + '\', ''))"
    exit 0
}

# dotnet format --include wants a path relative to the folder it runs in; an absolute path
# matches no file and exits 0 without formatting anything.
$relative = $file.Substring($root.Length + 1)
$before = (Get-FileHash -LiteralPath $file).Hash
$watch = [Diagnostics.Stopwatch]::StartNew()
Push-Location $root
$output = & dotnet format --include $relative 2>&1 | ForEach-Object { "$_" }
$code = $LASTEXITCODE
Pop-Location
$seconds = [math]::Round($watch.Elapsed.TotalSeconds, 2)
$changed = (Get-FileHash -LiteralPath $file).Hash -ne $before
Write-HookLog "tool=$($call.tool_name) file=$relative exit=$code changed=$changed dotnet_format_s=$seconds"

if ($code -ne 0) {
    # Any exit code other than 0 or 2 is a non-blocking error: the edit stands, the notice shows stderr.
    [Console]::Error.WriteLine("dotnet format failed for $relative (exit $code): " + ($output -join ' '))
    exit 1
}
if ($changed) {
    [ordered]@{
        hookSpecificOutput = [ordered]@{
            hookEventName     = 'PostToolUse'
            additionalContext = "dotnet format reformatted $($relative -replace '\\', '/') after this edit, so the file on disk differs from the text in the edit."
        }
    } | ConvertTo-Json -Compress
}
exit 0