[CmdletBinding()]
param(
    [string[]]$Path = @(
        'crates/common/src/formats',
        'crates/toon/src',
        'crates/ison/src',
        'crates/isonl/src',
        'crates/zon/src',
        'crates/tonl/src'
    )
)

$ErrorActionPreference = 'Stop'
Set-StrictMode -Version Latest

$workspaceRoot = Split-Path -Parent $PSScriptRoot
Push-Location -LiteralPath $workspaceRoot

function Get-BraceDelta {
    param(
        [AllowEmptyString()]
        [Parameter(Mandatory = $true)]
        [string]$Line
    )

    $open = ([regex]::Matches($Line, '\{')).Count
    $close = ([regex]::Matches($Line, '\}')).Count
    return $open - $close
}

function Test-AllowedLine {
    param(
        [AllowEmptyString()]
        [Parameter(Mandatory = $true)]
        [string]$Line,
        [AllowEmptyString()]
        [string]$PreviousLine
    )

    $sameLineComment = $Line -match '(^|\s)//\s*jade:\s*allow-panic\s+because:\s+\S'
    $previousLineComment = -not [string]::IsNullOrWhiteSpace($PreviousLine) -and
        $PreviousLine -match '^\s*//\s*jade:\s*allow-panic\s+because:\s+\S'

    return $sameLineComment -or (
        -not [string]::IsNullOrWhiteSpace($PreviousLine) -and
        $previousLineComment
    )
}

$patterns = @(
    'panic!\s*\(',
    '\.unwrap\s*\(',
    '\.expect\s*\('
)
$failures = [System.Collections.Generic.List[string]]::new()

try {
    foreach ($root in $Path) {
        if (-not (Test-Path -LiteralPath $root)) {
            throw "No-panic scan path does not exist: $root"
        }

        $files = Get-ChildItem -LiteralPath $root -Recurse -File -Filter '*.rs'
        foreach ($file in $files) {
            if (($file.FullName -split '[\\/]') -contains 'tests') {
                continue
            }

            $lines = Get-Content -LiteralPath $file.FullName
            $pendingTestModule = $false
            $insideTestModule = $false
            $braceDepth = 0
            $previousLine = ''
            for ($index = 0; $index -lt $lines.Count; $index += 1) {
                $line = [string]$lines[$index]
                $trimmed = $line.TrimStart()

                if ($insideTestModule) {
                    $braceDepth += Get-BraceDelta -Line $line
                    if ($braceDepth -le 0) {
                        $insideTestModule = $false
                        $braceDepth = 0
                    }
                    $previousLine = $line
                    continue
                }

                if ($trimmed.StartsWith('#[cfg(test)]')) {
                    $pendingTestModule = $true
                    $previousLine = $line
                    continue
                }

                if ($pendingTestModule -and $trimmed -match '^mod\s+tests\s*\{') {
                    $insideTestModule = $true
                    $braceDepth = Get-BraceDelta -Line $line
                    $pendingTestModule = $false
                    $previousLine = $line
                    continue
                }
                if (-not $trimmed.StartsWith('#[')) {
                    $pendingTestModule = $false
                }

                if ($trimmed.StartsWith('//')) {
                    $previousLine = $line
                    continue
                }

                foreach ($pattern in $patterns) {
                    if ($line -match $pattern -and -not (Test-AllowedLine -Line $line -PreviousLine $previousLine)) {
                        $relative = Resolve-Path -LiteralPath $file.FullName -Relative
                        $failures.Add("${relative}:$($index + 1): panic surface requires removal, fallible propagation, or a strict '// jade: allow-panic because: <reason>' comment directly beside this call")
                    }
                }

                $previousLine = $line
            }
        }
    }

    if ($failures.Count -gt 0) {
        $failures | ForEach-Object { Write-Error $_ }
        throw "No-panic gate found $($failures.Count) unapproved panic surface(s)."
    }

    Write-Host "No-panic gate passed for $($Path.Count) root(s)."
}
finally {
    Pop-Location
}