<#
.SYNOPSIS
    Rebuild all bundle artifacts by concatenating inputs per bundleconfig.json (strip BOM, no minify).
.DESCRIPTION
    No dependency on BuildBundlerMinifier. Deterministic pure concatenation:
      1. Read bundleconfig.json
      2. For each bundle: read input files in order, strip leading UTF-8 BOM, join with CRLF
      3. Only write out minify.enabled=false artifacts (overwrite committed files)
         For minify.enabled=true artifacts (minified CSS), skip generation (requires tooling)
    Output is byte-identical to BuildBundlerMinifier (SHA256 verified).
.PARAMETER Verify
    Verify-only mode: compare generated content with committed files, report mismatches, do NOT modify files.
.EXAMPLE
    .\rebuild-bundles.ps1           # Rebuild and overwrite committed bundle artifacts
    .\rebuild-bundles.ps1 -Verify   # Verify only, do not modify files
#>
[CmdletBinding()]
param(
    [switch]$Verify
)

$ErrorActionPreference = 'Stop'
$projectDir = Split-Path -Parent $MyInvocation.MyCommand.Path
$configPath = Join-Path $projectDir 'bundleconfig.json'

if (-not (Test-Path $configPath)) {
    throw "bundleconfig.json not found: $configPath"
}

# Read bundleconfig.json (strip // comments)
$configJson = Get-Content $configPath -Raw
$configJson = $configJson -replace '(?m)//.*$', ''
$bundles = $configJson | ConvertFrom-Json

$utf8NoBom = [System.Text.UTF8Encoding]::new($false)
$mismatches = @()

# CI 环境检测：CI 下 git checkout 后所有文件 mtime 几乎相同，增量检查不可靠
# 因此 CI 环境强制全量重建，本地开发才走增量
$isCI = -not [string]::IsNullOrEmpty($env:CI) `
        -or -not [string]::IsNullOrEmpty($env:JENKINS_HOME) `
        -or -not [string]::IsNullOrEmpty($env:BUILD_NUMBER) `
        -or -not [string]::IsNullOrEmpty($env:GITHUB_ACTIONS)

foreach ($bundle in $bundles) {
    $outputRel = $bundle.outputFileName
    $outputPath = Join-Path $projectDir $outputRel
    $isMinified = $bundle.minify.enabled

    # 增量检查：非 Verify、非 CI、非 minified，且 bundle 产物已存在时，
    # 若所有源文件都不比 bundle 产物新，则跳过此 bundle
    # 目的：让 target 挂到 Build 之前时，后端-only 改动不会触发重建，IDE F5 不变慢
    # CI 环境强制全量：git checkout 后 mtime 不可靠，必须重建保证部署产物正确
    if (-not $Verify -and -not $isCI -and -not $isMinified -and (Test-Path $outputPath)) {
        $outputMtime = (Get-Item $outputPath).LastWriteTime
        $stale = $false
        foreach ($inputRel in $bundle.inputFiles) {
            $inputPath = Join-Path $projectDir $inputRel
            if ((Test-Path $inputPath) -and (Get-Item $inputPath).LastWriteTime -gt $outputMtime) {
                $stale = $true
                break
            }
        }
        if (-not $stale) {
            Write-Host ("[UP-TO-DATE] {0}" -f $outputRel) -ForegroundColor DarkGray
            continue
        }
    }

    Write-Host ("[{0}] {1}" -f $(if ($isMinified) { 'SKIP-MIN' } else { 'BUILD' }), $outputRel)

    # Check input files exist + no BOM
    $parts = [System.Collections.Generic.List[string]]::new()
    $missingInputs = @()
    $bomInputs = @()

    foreach ($inputRel in $bundle.inputFiles) {
        $inputPath = Join-Path $projectDir $inputRel
        if (-not (Test-Path $inputPath)) {
            $missingInputs += $inputRel
            continue
        }
        # Detect BOM by reading raw bytes
        $bytes = [System.IO.File]::ReadAllBytes($inputPath)
        $hasBom = ($bytes.Length -ge 3 -and $bytes[0] -eq 0xEF -and $bytes[1] -eq 0xBB -and $bytes[2] -eq 0xBF)
        if ($hasBom) {
            $bomInputs += $inputRel
        }
        # Read text (UTF8, BOM auto-stripped by ReadAllText)
        $text = [System.IO.File]::ReadAllText($inputPath, [System.Text.Encoding]::UTF8)
        # Normalize CRLF to LF (bundle artifacts use LF in git repo)
        $text = $text -replace "`r`n", "`n"
        $parts.Add($text)
    }

    if ($missingInputs.Count -gt 0) {
        # 缺失输入文件：Verify 模式报错；重建模式只警告不 fail，避免阻塞 CI 主构建
        # 重建模式下跳过此 bundle（保留已提交的产物）
        $level = $(if ($Verify) { 'ERROR' } else { 'WARN' })
        $color = $(if ($Verify) { 'Red' } else { 'Yellow' })
        Write-Host "  [$level] Missing input files:" -ForegroundColor $color
        foreach ($m in $missingInputs) { Write-Host "    - $m" }
        if ($Verify) {
            $mismatches += "$outputRel : missing inputs ($($missingInputs -join ', '))"
        }
        continue
    }
    if ($bomInputs.Count -gt 0) {
        # Verify 模式：BOM 是源文件问题，报错阻止提交
        # 重建模式：BOM 会在读取时自动剥离（ReadAllText 处理），只警告不 fail，避免阻塞 CI 部署
        $level = $(if ($Verify) { 'ERROR' } else { 'WARN' })
        $color = $(if ($Verify) { 'Red' } else { 'Yellow' })
        Write-Host "  [$level] Input files have BOM (will be stripped on rebuild):" -ForegroundColor $color
        foreach ($b in $bomInputs) { Write-Host "    - $b" }
        if ($Verify) {
            $mismatches += "$outputRel : input BOM ($($bomInputs -join ', '))"
        }
    }

    # Pure concatenation with LF separator between files (matches committed bundle artifacts)
    $content = [string]::Join("`n", $parts)

    # For minified artifacts, only report, do not write
    if ($isMinified) {
        Write-Host "  (minified artifact, skip write, only input check)" -ForegroundColor Yellow
        continue
    }

    if ($Verify) {
        # Verify mode: compare with committed file
        if (-not (Test-Path $outputPath)) {
            Write-Host "  [ERROR] Output file not found: $outputRel" -ForegroundColor Red
            $mismatches += "$outputRel : output file not found"
            continue
        }
        $existing = [System.IO.File]::ReadAllText($outputPath, [System.Text.Encoding]::UTF8)
        if ($existing -ne $content) {
            Write-Host "  [MISMATCH] Differs from committed version" -ForegroundColor Red
            $mismatches += "$outputRel : out of sync (source changed but bundle not rebuilt)"
        } else {
            Write-Host "  [OK] Matches committed version" -ForegroundColor Green
        }
    } else {
        # Rebuild mode: write (no BOM)
        $dir = Split-Path $outputPath -Parent
        if (-not (Test-Path $dir)) { New-Item -ItemType Directory -Path $dir -Force | Out-Null }
        [System.IO.File]::WriteAllText($outputPath, $content, $utf8NoBom)
        Write-Host "  [DONE] Written ($($content.Length) chars)" -ForegroundColor Green
    }
}

Write-Host ""
if ($mismatches.Count -gt 0) {
    # Verify 模式：有问题则 fail（阻止提交不规范的状态）
    # 重建模式：永远不 fail，避免阻塞 CI 主构建（缺失/BOM 等已在循环内警告并跳过）
    if ($Verify) {
        Write-Host "=== Result: ISSUES FOUND (Verify mode) ===" -ForegroundColor Red
        foreach ($m in $mismatches) { Write-Host "  - $m" }
        exit 1
    } else {
        Write-Host "=== Result: COMPLETED WITH WARNINGS (Rebuild mode) ===" -ForegroundColor Yellow
        foreach ($m in $mismatches) { Write-Host "  - $m" }
        Write-Host "  (warnings do not block build in rebuild mode)" -ForegroundColor DarkGray
        exit 0
    }
} else {
    Write-Host "=== Result: ALL PASSED ===" -ForegroundColor Green
    exit 0
}