param(
    [string]$RepoRoot = (Resolve-Path (Join-Path $PSScriptRoot "..")).Path
)

$ErrorActionPreference = "Stop"

$targets = @(
    (Join-Path $RepoRoot "docs/tsl/index.md"),
    (Join-Path $RepoRoot "docs/tsl/syntax"),
    (Join-Path $RepoRoot "docs/tsl/finance"),
    (Join-Path $RepoRoot "docs/tsl/reference")
)

$excludeFragments = @(
    "\docs\plans\",
    "\archive\",
    "\docs\tsl\legacy\",
    "\docs\tsl\syntax_book\"
)

$pattern = '(?i)\b(?:syntax_book|legacy)\b'

function Get-RelativePath([string]$basePath, [string]$childPath) {
    $baseUri = [System.Uri]::new(($basePath.TrimEnd('\', '/') + [System.IO.Path]::DirectorySeparatorChar))
    $childUri = [System.Uri]::new($childPath)
    return [System.Uri]::UnescapeDataString($baseUri.MakeRelativeUri($childUri).ToString()).Replace('\', '/')
}

$files = foreach ($target in $targets) {
    if (!(Test-Path -LiteralPath $target)) {
        throw "Target not found: $target"
    }

    if ((Get-Item -LiteralPath $target).PSIsContainer) {
        Get-ChildItem -LiteralPath $target -Recurse -File -Filter *.md
    }
    else {
        Get-Item -LiteralPath $target
    }
}

$activeFiles = $files |
    Where-Object {
        $fullName = $_.FullName
        foreach ($fragment in $excludeFragments) {
            if ($fullName -like "*$fragment*") {
                return $false
            }
        }
        return $true
    } |
    Sort-Object FullName -Unique

$hits = foreach ($file in $activeFiles) {
    Select-String -Path $file.FullName -Pattern $pattern -AllMatches
}

if ($hits.Count -eq 0) {
    Write-Output "No legacy references found in active TSL docs."
    exit 0
}

Write-Output "Legacy references found in active TSL docs:"
foreach ($hit in $hits) {
    $relativePath = Get-RelativePath -basePath $RepoRoot -childPath $hit.Path
    Write-Output ("{0}:{1}: {2}" -f $relativePath, $hit.LineNumber, $hit.Line.Trim())
}

Write-Output ("Total files scanned: {0}" -f $activeFiles.Count)
Write-Output ("Total legacy hits: {0}" -f $hits.Count)
exit 1