package cmd

import (
    "bytes"
    "context"
    "fmt"
    "os/exec"
    "strings"
    "time"

    "github.com/cloudmigration/drive-migrator/internal/tracker"
    "github.com/sirupsen/logrus"
    "github.com/spf13/cobra"
)

var (
    sourceName   string
    sourceType   string
    destName     string
    destType     string
    trackFile    string
    resume       bool
    include      []string
    exclude      []string

    // Source remote config flags
    sourceURL   string
    sourceUser  string
    sourcePass  string
    sourceSAFile string

    // Dest remote config flags
    destURL   string
    destUser  string
    destPass  string
    destSAFile string
)

func init() {
    migrateCmd := &cobra.Command{
        Use:   "migrate",
        Short: "Run migration between two cloud drives (auto-creates remotes if needed)",
        RunE:  runMigrate,
    }

    migrateCmd.Flags().StringVar(&sourceName, "source-name", "", "Nama remote/source di rclone (akan dibuat otomatis jika belum ada)")
    migrateCmd.Flags().StringVar(&sourceType, "source-type", "", "Tipe cloud drive sumber (nextcloud, webdav, gdrive, onedrive, dll)")
    migrateCmd.Flags().StringVar(&destName, "dest-name", "", "Nama remote/tujuan di rclone (akan dibuat otomatis jika belum ada)")
    migrateCmd.Flags().StringVar(&destType, "dest-type", "", "Tipe cloud drive tujuan")
    migrateCmd.Flags().StringVar(&trackFile, "track-file", "migration.db", "Lokasi file tracking (bolt)")
    migrateCmd.Flags().BoolVar(&resume, "resume", false, "Lanjutkan migrasi yang terhenti")
    migrateCmd.Flags().StringSliceVar(&include, "include", nil, "Pola file/folder yang akan dimigrasikan (bisa diulang)")
    migrateCmd.Flags().StringSliceVar(&exclude, "exclude", nil, "Pola file/folder yang akan dikecualikan (bisa diulang)")

    // Source remote extra flags
    migrateCmd.Flags().StringVar(&sourceURL, "source-url", "", "URL untuk remote sumber (Nextcloud/WebDAV)")
    migrateCmd.Flags().StringVar(&sourceUser, "source-user", "", "Username remote sumber")
    migrateCmd.Flags().StringVar(&sourcePass, "source-pass", "", "Password remote sumber")
    migrateCmd.Flags().StringVar(&sourceSAFile, "source-sa-file", "", "Service account JSON untuk GDrive sumber")

    // Dest remote extra flags
    migrateCmd.Flags().StringVar(&destURL, "dest-url", "", "URL untuk remote tujuan (Nextcloud/WebDAV)")
    migrateCmd.Flags().StringVar(&destUser, "dest-user", "", "Username remote tujuan")
    migrateCmd.Flags().StringVar(&destPass, "dest-pass", "", "Password remote tujuan")
    migrateCmd.Flags().StringVar(&destSAFile, "dest-sa-file", "", "Service account JSON untuk GDrive tujuan")

    migrateCmd.MarkFlagRequired("source-name")
    migrateCmd.MarkFlagRequired("dest-name")

    rootCmd.AddCommand(migrateCmd)
}

// ensureRemoteExists checks if remote exists and if not, creates it using provided parameters.
func ensureRemoteExists(ctx context.Context, name, rtype, url, user, pass, saFile string) error {
    // Check if remote exists using rclone listremotes
    listCmd := exec.CommandContext(ctx, "rclone", "listremotes")
    var out bytes.Buffer
    listCmd.Stdout = &out
    if err := listCmd.Run(); err != nil {
        return fmt.Errorf("failed to list rclone remotes: %w", err)
    }
    remotes := strings.Split(out.String(), "\n")
    for _, r := range remotes {
        if strings.TrimSuffix(r, ":") == name {
            logrus.Debugf("Remote %s already exists", name)
            return nil
        }
    }

    logrus.Infof("Remote %s not found, creating...", name)

    switch strings.ToLower(rtype) {
    case "nextcloud", "webdav":
        if url == "" {
            return fmt.Errorf("url is required to create webdav/nextcloud remote")
        }
        // If pass provided, obscure it first
        encPass := pass
        if pass != "" {
            obscCmd := exec.CommandContext(ctx, "rclone", "obscure", pass)
            var ob bytes.Buffer
            obscCmd.Stdout = &ob
            if err := obscCmd.Run(); err != nil {
                return fmt.Errorf("failed to obscure password: %w", err)
            }
            encPass = strings.TrimSpace(ob.String())
        }
        args := []string{"config", "create", name, "webdav", "vendor", "nextcloud", "url", url}
        if user != "" {
            args = append(args, "user", user)
        }
        if encPass != "" {
            args = append(args, "pass", encPass)
        }
        createCmd := exec.CommandContext(ctx, "rclone", args...)
        createCmd.Stdout = logrus.StandardLogger().Writer()
        createCmd.Stderr = logrus.StandardLogger().Writer()
        if err := createCmd.Run(); err != nil {
            return fmt.Errorf("failed to create remote: %w", err)
        }
    case "drive", "gdrive":
        if saFile == "" {
            return fmt.Errorf("sa-file is required to create gdrive remote")
        }
        args := []string{"config", "create", name, "drive", "service_account_file", saFile}
        createCmd := exec.CommandContext(ctx, "rclone", args...)
        createCmd.Stdout = logrus.StandardLogger().Writer()
        createCmd.Stderr = logrus.StandardLogger().Writer()
        if err := createCmd.Run(); err != nil {
            return fmt.Errorf("failed to create gdrive remote: %w", err)
        }
    default:
        return fmt.Errorf("auto create not supported for remote type: %s", rtype)
    }

    logrus.Infof("Remote %s created successfully", name)
    return nil
}

func runMigrate(cmd *cobra.Command, args []string) error {
    ctx := context.Background()

    // Ensure remotes exist or create them automatically
    if err := ensureRemoteExists(ctx, sourceName, sourceType, sourceURL, sourceUser, sourcePass, sourceSAFile); err != nil {
        return err
    }
    if err := ensureRemoteExists(ctx, destName, destType, destURL, destUser, destPass, destSAFile); err != nil {
        return err
    }

    // Initialize tracker
    t, err := tracker.NewTracker(trackFile)
    if err != nil {
        return fmt.Errorf("failed to initialize tracker: %w", err)
    }
    defer t.Close()

    // Create job ID
    jobID := fmt.Sprintf("%s-to-%s-%d", sourceName, destName, time.Now().Unix())

    job := &tracker.MigrationJob{
        ID:         jobID,
        SourceName: sourceName,
        DestName:   destName,
        Status:     tracker.StatusInProgress,
        StartTime:  time.Now(),
    }
    if err := t.CreateJob(job); err != nil {
        return fmt.Errorf("failed to create job: %w", err)
    }

    logrus.Infof("Starting migration from %s to %s (Job ID: %s)", sourceName, destName, jobID)

    // Build rclone arguments
    rcloneArgs := []string{"copy", sourceName + ":", destName + ":", "--progress", "--stats", "10s"}

    for _, pattern := range include {
        rcloneArgs = append(rcloneArgs, "--include", pattern)
    }
    for _, pattern := range exclude {
        rcloneArgs = append(rcloneArgs, "--exclude", pattern)
    }
    if resume {
        rcloneArgs = append(rcloneArgs, "--ignore-existing")
        logrus.Info("Resume mode: ignoring existing files")
    }

    cmdRclone := exec.CommandContext(ctx, "rclone", rcloneArgs...)
    cmdRclone.Stdout = logrus.StandardLogger().Writer()
    cmdRclone.Stderr = logrus.StandardLogger().Writer()

    start := time.Now()

    if err := cmdRclone.Run(); err != nil {
        job.Status = tracker.StatusFailed
        job.EndTime = time.Now()
        job.ErrorMessage = err.Error()
        t.UpdateJob(job)
        return fmt.Errorf("rclone finished with error: %w", err)
    }

    job.Status = tracker.StatusCompleted
    job.EndTime = time.Now()
    t.UpdateJob(job)

    elapsed := time.Since(start)
    logrus.Infof("Migration completed in %s (Job ID: %s)", elapsed, jobID)
    t.LogProgress(jobID)
    return nil
}