param(
    [ValidateSet("Backup", "Restore", "Verify")]
    [string]$Action = "Backup",

    [string]$ProjectDir = ".",
    [string]$ComposeFile = "docker-compose.prod.yml",
    [string]$EnvFile = ".env",
    [string]$BackupDir = "backups",
    [string]$BackupPath,

    [string]$AppService = "app",
    [string]$PostgresService = "postgres",
    [string]$MinioService = "minio",
    [string]$HelperImage = "busybox:1.36",

    [switch]$SkipDatabaseBackup,
    [switch]$SkipObjectStorageBackup,
    [switch]$SkipObjectStorageRestore,
    [switch]$RestoreEnv,

    [int]$HealthTimeoutSeconds = 120,

    [string]$ConfirmRestore
)

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

$RestoreConfirmPhrase = "RESTORE_FLNXI_DATA"

function Write-Info {
    param([string]$Message)
    Write-Host "[INFO] $Message"
}

function Write-Ok {
    param([string]$Message)
    Write-Host "[OK] $Message"
}

function Write-Warn {
    param([string]$Message)
    Write-Warning $Message
}

function Resolve-ExistingFile {
    param([string]$Path, [string]$Label)

    if (-not (Test-Path -LiteralPath $Path -PathType Leaf)) {
        throw "$Label 不存在：$Path"
    }

    return (Resolve-Path -LiteralPath $Path).Path
}

function Resolve-ProjectPath {
    param([string]$Path)

    if (-not (Test-Path -LiteralPath $Path -PathType Container)) {
        throw "项目目录不存在：$Path"
    }

    return (Resolve-Path -LiteralPath $Path).Path
}

function Read-EnvFile {
    param([string]$Path)

    $values = @{}
    if (-not (Test-Path -LiteralPath $Path -PathType Leaf)) {
        return $values
    }

    foreach ($line in Get-Content -LiteralPath $Path) {
        if ($line -match '^\s*#' -or $line -notmatch '=') {
            continue
        }

        $parts = $line -split '=', 2
        $key = $parts[0].Trim()
        if ([string]::IsNullOrWhiteSpace($key)) {
            continue
        }

        $value = $parts[1].Trim()
        if (($value.StartsWith('"') -and $value.EndsWith('"')) -or ($value.StartsWith("'") -and $value.EndsWith("'"))) {
            $value = $value.Substring(1, $value.Length - 2)
        }
        $values[$key] = $value
    }

    return $values
}

function Get-EnvValue {
    param(
        [hashtable]$EnvValues,
        [string]$Name,
        [string]$Default = ""
    )

    if ($EnvValues.ContainsKey($Name)) {
        return $EnvValues[$Name]
    }

    return $Default
}

function Invoke-DockerCompose {
    param([string[]]$Arguments)

    & docker @Arguments
    if ($LASTEXITCODE -ne 0) {
        throw "docker 命令失败，退出码：$LASTEXITCODE"
    }
}

function Get-ComposeArgs {
    param([string]$ComposeFilePath, [string]$EnvFilePath)

    $args = @("compose", "-f", $ComposeFilePath)
    if (Test-Path -LiteralPath $EnvFilePath -PathType Leaf) {
        $args += @("--env-file", $EnvFilePath)
    }
    return $args
}

function Get-ServiceContainerId {
    param([string[]]$ComposeArgs, [string]$Service)

    $containerId = (& docker @ComposeArgs ps -q $Service).Trim()
    if ($LASTEXITCODE -ne 0 -or [string]::IsNullOrWhiteSpace($containerId)) {
        throw "未找到服务容器：$Service。请先确认服务已启动。"
    }

    return $containerId
}

function Test-ExternalDatabase {
    param([hashtable]$EnvValues)

    $databaseUrl = Get-EnvValue $EnvValues "DATABASE_URL"
    if ([string]::IsNullOrWhiteSpace($databaseUrl)) {
        return $false
    }

    return ($databaseUrl -notmatch '@postgres:5432' -and $databaseUrl -notmatch '@[^/]*postgres[^/]*:5432')
}

function Backup-Database {
    param([string[]]$ComposeArgs, [string]$Service, [string]$OutputPath)

    Write-Info "备份 Compose 内置 PostgreSQL"
    Invoke-DockerCompose ($ComposeArgs + @("up", "-d", $Service))
    $containerId = Get-ServiceContainerId -ComposeArgs $ComposeArgs -Service $Service
    $containerBackupPath = "/tmp/flnxi-backup.sql"

    Invoke-DockerCompose ($ComposeArgs + @(
        "exec", "-T", $Service,
        "sh", "-c",
        'pg_dump -U "$POSTGRES_USER" -d "$POSTGRES_DB" --clean --if-exists --no-owner --no-privileges -f /tmp/flnxi-backup.sql && test -s /tmp/flnxi-backup.sql'
    ))

    & docker cp "${containerId}:${containerBackupPath}" $OutputPath
    if ($LASTEXITCODE -ne 0 -or -not (Test-Path -LiteralPath $OutputPath -PathType Leaf)) {
        throw "数据库备份复制失败：$OutputPath"
    }

    Invoke-DockerCompose ($ComposeArgs + @("exec", "-T", $Service, "sh", "-c", "rm -f $containerBackupPath"))
    Write-Ok "数据库备份完成：$OutputPath"
}

function Restore-Database {
    param([string[]]$ComposeArgs, [string]$Service, [string]$InputPath)

    Write-Info "恢复 Compose 内置 PostgreSQL"
    Invoke-DockerCompose ($ComposeArgs + @("up", "-d", $Service))
    $containerId = Get-ServiceContainerId -ComposeArgs $ComposeArgs -Service $Service
    $containerRestorePath = "/tmp/flnxi-restore.sql"

    & docker cp $InputPath "${containerId}:${containerRestorePath}"
    if ($LASTEXITCODE -ne 0) {
        throw "数据库备份文件复制到容器失败"
    }

    Invoke-DockerCompose ($ComposeArgs + @(
        "exec", "-T", $Service,
        "sh", "-c",
        'psql -v ON_ERROR_STOP=1 -U "$POSTGRES_USER" -d "$POSTGRES_DB" -f /tmp/flnxi-restore.sql'
    ))
    Invoke-DockerCompose ($ComposeArgs + @("exec", "-T", $Service, "sh", "-c", "rm -f $containerRestorePath"))
    Write-Ok "数据库恢复完成"
}

function Backup-ObjectStorage {
    param([string]$VolumeName, [string]$OutputPath, [string]$HelperImage)

    if ([string]::IsNullOrWhiteSpace($VolumeName)) {
        throw "MINIO_VOLUME_NAME 为空，无法备份内置对象存储卷。"
    }

    Write-Info "备份 Compose 内置 MinIO 数据卷：$VolumeName"
    $backupDir = Split-Path -Parent $OutputPath
    & docker volume inspect $VolumeName *> $null
    if ($LASTEXITCODE -ne 0) {
        throw "未找到 MinIO 数据卷：$VolumeName"
    }

    & docker run --rm -v "${VolumeName}:/source:ro" -v "${backupDir}:/backup" $HelperImage sh -c "cd /source && tar -czf /backup/minio-data.tar.gz ."
    if ($LASTEXITCODE -ne 0 -or -not (Test-Path -LiteralPath $OutputPath -PathType Leaf)) {
        throw "对象存储备份失败。请确认 helper 镜像可用：$HelperImage"
    }

    Write-Ok "对象存储备份完成：$OutputPath"
}

function Restore-ObjectStorage {
    param([string]$VolumeName, [string]$InputPath, [string]$HelperImage)

    if ([string]::IsNullOrWhiteSpace($VolumeName)) {
        throw "MINIO_VOLUME_NAME 为空，无法恢复内置对象存储卷。"
    }

    $backupDir = Split-Path -Parent $InputPath
    Write-Info "恢复 Compose 内置 MinIO 数据卷：$VolumeName"
    & docker volume inspect $VolumeName *> $null
    if ($LASTEXITCODE -ne 0) {
        & docker volume create $VolumeName | Out-Null
        if ($LASTEXITCODE -ne 0) {
            throw "创建 MinIO 数据卷失败：$VolumeName"
        }
    }

    & docker run --rm -v "${VolumeName}:/target" -v "${backupDir}:/backup:ro" $HelperImage sh -c "rm -rf /target/* /target/.[!.]* /target/..?* 2>/dev/null || true; cd /target && tar -xzf /backup/minio-data.tar.gz"
    if ($LASTEXITCODE -ne 0) {
        throw "对象存储恢复失败。请确认 helper 镜像可用：$HelperImage"
    }

    Write-Ok "对象存储恢复完成"
}

function Save-CommandOutput {
    param([string]$Path, [scriptblock]$Command)

    try {
        & $Command *>&1 | Out-File -LiteralPath $Path -Encoding utf8
    } catch {
        "命令执行失败：$($_.Exception.Message)" | Out-File -LiteralPath $Path -Encoding utf8
    }
}

function Invoke-Verify {
    param([string[]]$ComposeArgs, [hashtable]$EnvValues, [int]$TimeoutSeconds)

    Write-Info "检查 Compose 配置"
    Invoke-DockerCompose ($ComposeArgs + @("config", "--quiet"))

    Write-Info "查看容器状态"
    Invoke-DockerCompose ($ComposeArgs + @("ps"))

    $publicUrl = Get-EnvValue $EnvValues "APP_PUBLIC_URL"
    if ([string]::IsNullOrWhiteSpace($publicUrl)) {
        $publicUrl = Get-EnvValue $EnvValues "NEXTAUTH_URL"
    }

    if ([string]::IsNullOrWhiteSpace($publicUrl)) {
        Write-Warn "未配置 APP_PUBLIC_URL / NEXTAUTH_URL，跳过 /api/health HTTP 验收。"
        return
    }

    $healthUrl = $publicUrl.TrimEnd("/") + "/api/health"
    Write-Info "检查健康接口：$healthUrl"
    $deadline = (Get-Date).AddSeconds($TimeoutSeconds)
    do {
        try {
            $response = Invoke-WebRequest -Uri $healthUrl -UseBasicParsing -TimeoutSec 10
            if ($response.StatusCode -eq 200) {
                Write-Ok "/api/health 正常"
                return
            }
        } catch {
            Start-Sleep -Seconds 5
        }
    } while ((Get-Date) -lt $deadline)

    throw "/api/health 在 $TimeoutSeconds 秒内没有通过：$healthUrl"
}

$resolvedProjectDir = Resolve-ProjectPath $ProjectDir
Push-Location $resolvedProjectDir
try {
    $composePath = Resolve-ExistingFile $ComposeFile "Compose 文件"
    $envPath = Join-Path $resolvedProjectDir $EnvFile
    $envValues = Read-EnvFile $envPath
    $composeArgs = Get-ComposeArgs -ComposeFilePath $composePath -EnvFilePath $envPath

    switch ($Action) {
        "Backup" {
            $timestamp = Get-Date -Format "yyyyMMdd-HHmmss"
            $backupRoot = Join-Path $resolvedProjectDir $BackupDir
            $targetDir = Join-Path $backupRoot "flnxi-backup-$timestamp"
            New-Item -ItemType Directory -Path $targetDir -Force | Out-Null

            Copy-Item -LiteralPath $composePath -Destination (Join-Path $targetDir "docker-compose.prod.yml") -Force
            if (Test-Path -LiteralPath $envPath -PathType Leaf) {
                Copy-Item -LiteralPath $envPath -Destination (Join-Path $targetDir ".env") -Force
            }
            if (Test-Path -LiteralPath "VERSION.txt" -PathType Leaf) {
                Copy-Item -LiteralPath "VERSION.txt" -Destination (Join-Path $targetDir "VERSION.txt") -Force
            }

            Save-CommandOutput -Path (Join-Path $targetDir "compose-config.txt") -Command { & docker @composeArgs config }
            Save-CommandOutput -Path (Join-Path $targetDir "compose-ps.txt") -Command { & docker @composeArgs ps }
            Save-CommandOutput -Path (Join-Path $targetDir "docker-images.txt") -Command { & docker images --digests }

            $externalDb = Test-ExternalDatabase $envValues
            if ($SkipDatabaseBackup) {
                "已按参数跳过数据库备份。请确认外部备份已存在。" | Out-File -LiteralPath (Join-Path $targetDir "DATABASE_BACKUP_SKIPPED.txt") -Encoding utf8
            } elseif ($externalDb) {
                "检测到 DATABASE_URL 指向外部数据库。本脚本不会自动备份外部数据库，请按客户现场数据库方案单独备份。" | Out-File -LiteralPath (Join-Path $targetDir "EXTERNAL_DATABASE_BACKUP_REQUIRED.txt") -Encoding utf8
            } else {
                Backup-Database -ComposeArgs $composeArgs -Service $PostgresService -OutputPath (Join-Path $targetDir "postgres.sql")
            }

            $minioVolumeName = Get-EnvValue $envValues "MINIO_VOLUME_NAME" "flnxi-minio-data"
            if ($SkipObjectStorageBackup) {
                "已按参数跳过对象存储备份。请确认外部 S3 / MinIO 或 Docker 卷已有独立备份。" | Out-File -LiteralPath (Join-Path $targetDir "OBJECT_STORAGE_BACKUP_SKIPPED.txt") -Encoding utf8
            } else {
                Backup-ObjectStorage -VolumeName $minioVolumeName -OutputPath (Join-Path $targetDir "minio-data.tar.gz") -HelperImage $HelperImage
            }

            $manifest = [ordered]@{
                createdAt = (Get-Date).ToString("s")
                projectDir = $resolvedProjectDir
                composeFile = $composePath
                envFile = $envPath
                appImage = Get-EnvValue $envValues "APP_IMAGE"
                appPublicUrl = Get-EnvValue $envValues "APP_PUBLIC_URL"
                postgresService = $PostgresService
                minioVolumeName = $minioVolumeName
                externalDatabase = $externalDb
                restoreConfirmPhrase = $RestoreConfirmPhrase
            }
            $manifest | ConvertTo-Json -Depth 5 | Out-File -LiteralPath (Join-Path $targetDir "manifest.json") -Encoding utf8
            Write-Ok "备份目录：$targetDir"
        }

        "Restore" {
            if ([string]::IsNullOrWhiteSpace($BackupPath)) {
                throw "恢复必须传入 -BackupPath。"
            }
            if ($ConfirmRestore -ne $RestoreConfirmPhrase) {
                throw "恢复会覆盖客户数据。请显式传入 -ConfirmRestore $RestoreConfirmPhrase。"
            }

            $sourceDir = Resolve-ProjectPath $BackupPath
            $dbBackup = Join-Path $sourceDir "postgres.sql"
            $objectBackup = Join-Path $sourceDir "minio-data.tar.gz"

            Write-Warn "即将恢复备份目录：$sourceDir"
            Invoke-DockerCompose ($composeArgs + @("stop", $AppService))

            if ($RestoreEnv -and (Test-Path -LiteralPath (Join-Path $sourceDir ".env") -PathType Leaf)) {
                $envBackupPath = Join-Path $resolvedProjectDir (".env.before-restore-" + (Get-Date -Format "yyyyMMdd-HHmmss"))
                if (Test-Path -LiteralPath $envPath -PathType Leaf) {
                    Copy-Item -LiteralPath $envPath -Destination $envBackupPath -Force
                }
                Copy-Item -LiteralPath (Join-Path $sourceDir ".env") -Destination $envPath -Force
                $envValues = Read-EnvFile $envPath
                Write-Ok ".env 已恢复，恢复前副本：$envBackupPath"
            }

            if (Test-Path -LiteralPath $dbBackup -PathType Leaf) {
                Restore-Database -ComposeArgs $composeArgs -Service $PostgresService -InputPath $dbBackup
            } else {
                Write-Warn "备份目录没有 postgres.sql，跳过数据库恢复。"
            }

            if (-not $SkipObjectStorageRestore -and (Test-Path -LiteralPath $objectBackup -PathType Leaf)) {
                Invoke-DockerCompose ($composeArgs + @("stop", $MinioService))
                $minioVolumeName = Get-EnvValue $envValues "MINIO_VOLUME_NAME" "flnxi-minio-data"
                Restore-ObjectStorage -VolumeName $minioVolumeName -InputPath $objectBackup -HelperImage $HelperImage
            } elseif ($SkipObjectStorageRestore) {
                Write-Warn "已按参数跳过对象存储恢复。"
            } else {
                Write-Warn "备份目录没有 minio-data.tar.gz，跳过对象存储恢复。"
            }

            Invoke-DockerCompose ($composeArgs + @("up", "-d"))
            Invoke-Verify -ComposeArgs $composeArgs -EnvValues (Read-EnvFile $envPath) -TimeoutSeconds $HealthTimeoutSeconds
            Write-Ok "恢复和基础验收完成"
        }

        "Verify" {
            Invoke-Verify -ComposeArgs $composeArgs -EnvValues $envValues -TimeoutSeconds $HealthTimeoutSeconds
        }
    }
} finally {
    Pop-Location
}