// Copyright 2019 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT

package cmd

import (
	"context"
	"errors"
	"fmt"
	"image"
	"io"
	"io/fs"
	golog "log"
	"os"
	"path/filepath"
	"strings"
	"text/tabwriter"

	"forgejo.org/models/db"
	git_model "forgejo.org/models/git"
	"forgejo.org/models/gitea_migrations"
	migrate_base "forgejo.org/models/gitea_migrations/base"
	repo_model "forgejo.org/models/repo"
	user_model "forgejo.org/models/user"
	"forgejo.org/modules/container"
	"forgejo.org/modules/log"
	"forgejo.org/modules/setting"
	"forgejo.org/modules/storage"
	"forgejo.org/services/doctor"

	exif_terminator "code.superseriousbusiness.org/exif-terminator"
	"github.com/urfave/cli/v3"
)

// CmdDoctor represents the available doctor sub-command.
func cmdDoctor() *cli.Command {
	return &cli.Command{
		Name:        "doctor",
		Usage:       "Diagnose and optionally fix problems, convert or re-create database tables",
		Description: "A command to diagnose problems with the current Forgejo instance according to the given configuration. Some problems can optionally be fixed by modifying the database or data storage.",

		Commands: []*cli.Command{
			cmdDoctorCheck(),
			cmdRecreateTable(),
			cmdDoctorConvert(),
			cmdAvatarStripExif(),
			cmdCleanupCommitStatuses(),
		},
	}
}

func cmdDoctorCheck() *cli.Command {
	return &cli.Command{
		Name:        "check",
		Usage:       "Diagnose and optionally fix problems",
		Description: "A command to diagnose problems with the current Forgejo instance according to the given configuration. Some problems can optionally be fixed by modifying the database or data storage.",
		Before:      noDanglingArgs,
		Action:      runDoctorCheck,
		Flags: []cli.Flag{
			&cli.BoolFlag{
				Name:  "list",
				Usage: "List the available checks",
			},
			&cli.BoolFlag{
				Name:  "default",
				Usage: "Run the default checks (if neither --run or --all is set, this is the default behaviour)",
			},
			&cli.StringSliceFlag{
				Name:  "run",
				Usage: "Run the provided checks - (if --default is set, the default checks will also run)",
			},
			&cli.BoolFlag{
				Name:  "all",
				Usage: "Run all the available checks",
			},
			&cli.BoolFlag{
				Name:  "fix",
				Usage: "Automatically fix what we can",
			},
			&cli.StringFlag{
				Name:  "log-file",
				Usage: `Name of the log file (no verbose log output by default). Set to "-" to output to stdout`,
			},
			&cli.BoolFlag{
				Name:    "color",
				Aliases: []string{"H"},
				Usage:   "Use color for outputted information",
			},
		},
	}
}

func cmdRecreateTable() *cli.Command {
	return &cli.Command{
		Name:      "recreate-table",
		Usage:     "Recreate tables from XORM definitions and copy the data.",
		ArgsUsage: "[TABLE]... : (TABLEs to recreate - leave blank for all)",
		Flags: []cli.Flag{
			&cli.BoolFlag{
				Name:  "debug",
				Usage: "Print SQL commands sent",
			},
		},
		Description: `The database definitions Forgejo uses change across versions, sometimes changing default values and leaving old unused columns.

This command will cause Xorm to recreate tables, copying over the data and deleting the old table.

You should back-up your database before doing this and ensure that your database is up-to-date first.`,
		Action: runRecreateTable,
	}
}

func cmdAvatarStripExif() *cli.Command {
	return &cli.Command{
		Name:   "avatar-strip-exif",
		Usage:  "Strip EXIF metadata from all images in the avatar storage",
		Before: noDanglingArgs,
		Action: runAvatarStripExif,
	}
}

func cmdCleanupCommitStatuses() *cli.Command {
	return &cli.Command{
		Name:  "cleanup-commit-status",
		Usage: "Cleanup extra records in commit_status table",
		Description: `Forgejo suffered from a bug which caused the creation of more entries in the
"commit_status" table than necessary. This operation removes the redundant
data caused by the bug. Removing this data is almost always safe.
These redundant records can be accessed by users through the API, making it
possible, but unlikely, that removing it could have an impact to
integrating services (API: /repos/{owner}/{repo}/commits/{ref}/statuses).

It is safe to run while Forgejo is online.

On very large Forgejo instances, the performance of operation will improve
if the buffer-size option is used with large values. Approximately 130 MB of
memory is required for every 100,000 records in the buffer.

Bug reference: https://codeberg.org/forgejo/forgejo/issues/10671
`,

		Before: multipleBefore(noDanglingArgs, PrepareConsoleLoggerLevel(log.INFO)),
		Action: runCleanupCommitStatus,
		Flags: []cli.Flag{
			&cli.BoolFlag{
				Name:    "verbose",
				Aliases: []string{"V"},
				Usage:   "Show process details",
			},
			&cli.BoolFlag{
				Name:  "dry-run",
				Usage: "Report statistics from the operation but do not modify the database",
			},
			&cli.IntFlag{
				Name:  "buffer-size",
				Usage: "Record count per query while iterating records; larger values are typically faster but use more memory",
				// See IterateByKeyset's documentation for performance notes which led to the choice of the default
				// buffer size for this operation.
				Value: 100000,
			},
			&cli.IntFlag{
				Name:  "delete-chunk-size",
				Usage: "Number of records to delete per DELETE query",
				Value: 1000,
			},
		},
	}
}

func runRecreateTable(stdCtx context.Context, ctx *cli.Command) error {
	stdCtx, cancel := installSignals(stdCtx)
	defer cancel()

	// Redirect the default golog to here
	golog.SetFlags(0)
	golog.SetPrefix("")
	golog.SetOutput(log.LoggerToWriter(log.GetLogger(log.DEFAULT).Info))

	debug := ctx.Bool("debug")
	setting.MustInstalled()
	setting.LoadDBSetting()

	if debug {
		setting.InitSQLLoggersForCli(log.DEBUG)
	} else {
		setting.InitSQLLoggersForCli(log.INFO)
	}

	setting.Database.LogSQL = debug
	if err := db.InitEngine(stdCtx); err != nil {
		fmt.Println(err)
		fmt.Println("Check if you are using the right config file. You can use a --config directive to specify one.")
		return nil
	}

	args := ctx.Args()
	names := make([]string, 0, ctx.NArg())
	for i := range ctx.NArg() {
		names = append(names, args.Get(i))
	}

	beans, err := db.NamesToBean(names...)
	if err != nil {
		return err
	}
	recreateTables := migrate_base.RecreateTables(beans...)

	return db.InitEngineWithMigration(stdCtx, func(x db.Engine) error {
		engine, err := db.GetMasterEngine(x)
		if err != nil {
			return err
		}

		if err := gitea_migrations.EnsureUpToDate(engine); err != nil {
			return err
		}

		return recreateTables(engine)
	})
}

func setupDoctorDefaultLogger(ctx *cli.Command, colorize bool) {
	// Silence the default loggers
	setupConsoleLogger(log.FATAL, log.CanColorStderr, os.Stderr)

	logFile := ctx.String("log-file")
	switch logFile {
	case "":
		return // if no doctor log-file is set, do not show any log from default logger
	case "-":
		setupConsoleLogger(log.TRACE, colorize, os.Stdout)
	default:
		logFile, _ = filepath.Abs(logFile)
		writeMode := log.WriterMode{Level: log.TRACE, WriterOption: log.WriterFileOption{FileName: logFile}}
		writer, err := log.NewEventWriter("console-to-file", "file", writeMode)
		if err != nil {
			log.FallbackErrorf("unable to create file log writer: %v", err)
			return
		}
		log.GetManager().GetLogger(log.DEFAULT).ReplaceAllWriters(writer)
	}
}

func runDoctorCheck(stdCtx context.Context, ctx *cli.Command) error {
	stdCtx, cancel := installSignals(stdCtx)
	defer cancel()

	colorize := log.CanColorStdout
	if ctx.IsSet("color") {
		colorize = ctx.Bool("color")
	}

	setupDoctorDefaultLogger(ctx, colorize)

	// Finally redirect the default golang's log to here
	golog.SetFlags(0)
	golog.SetPrefix("")
	golog.SetOutput(log.LoggerToWriter(log.GetLogger(log.DEFAULT).Info))

	if ctx.IsSet("list") {
		w := tabwriter.NewWriter(os.Stdout, 0, 8, 1, '\t', 0)
		_, _ = w.Write([]byte("Default\tName\tTitle\n"))
		doctor.SortChecks(doctor.Checks)
		for _, check := range doctor.Checks {
			if check.IsDefault {
				_, _ = w.Write([]byte{'*'})
			}
			_, _ = w.Write([]byte{'\t'})
			_, _ = w.Write([]byte(check.Name))
			_, _ = w.Write([]byte{'\t'})
			_, _ = w.Write([]byte(check.Title))
			_, _ = w.Write([]byte{'\n'})
		}
		return w.Flush()
	}

	var checks []*doctor.Check
	if ctx.Bool("all") {
		checks = make([]*doctor.Check, len(doctor.Checks))
		copy(checks, doctor.Checks)
	} else if ctx.IsSet("run") {
		addDefault := ctx.Bool("default")
		runNamesSet := container.SetOf(ctx.StringSlice("run")...)
		for _, check := range doctor.Checks {
			if (addDefault && check.IsDefault) || runNamesSet.Contains(check.Name) {
				checks = append(checks, check)
				runNamesSet.Remove(check.Name)
			}
		}
		if len(runNamesSet) > 0 {
			return fmt.Errorf("unknown checks: %q", strings.Join(runNamesSet.Values(), ","))
		}
	} else {
		for _, check := range doctor.Checks {
			if check.IsDefault {
				checks = append(checks, check)
			}
		}
	}
	return doctor.RunChecks(stdCtx, colorize, ctx.Bool("fix"), checks)
}

func runAvatarStripExif(ctx context.Context, c *cli.Command) error {
	ctx, cancel := installSignals(ctx)
	defer cancel()

	if err := initDB(ctx); err != nil {
		return err
	}
	if err := storage.Init(); err != nil {
		return err
	}

	type HasCustomAvatarRelativePath interface {
		CustomAvatarRelativePath() string
	}

	doExifStrip := func(obj HasCustomAvatarRelativePath, name string, target_storage storage.ObjectStorage) error {
		if obj.CustomAvatarRelativePath() == "" {
			return nil
		}

		log.Info("Stripping avatar for %s...", name)

		avatarFile, err := target_storage.Open(obj.CustomAvatarRelativePath())
		if err != nil {
			if errors.Is(err, fs.ErrNotExist) {
				return nil
			}
			return fmt.Errorf("storage.Avatars.Open: %w", err)
		}
		_, imgType, err := image.DecodeConfig(avatarFile)
		if err != nil {
			if errors.Is(err, image.ErrFormat) {
				return nil
			}
			return fmt.Errorf("image.DecodeConfig: %w", err)
		}

		// reset io.Reader for exif termination scan
		_, err = avatarFile.Seek(0, io.SeekStart)
		if err != nil {
			return fmt.Errorf("avatarFile.Seek: %w", err)
		}

		cleanedData, err := exif_terminator.Terminate(avatarFile, imgType)
		if err != nil && strings.Contains(err.Error(), "cannot be processed") {
			// expected error for an image type that isn't supported by exif_terminator
			log.Info("... image type %s is not supported by exif_terminator, skipping.", imgType)
			return nil
		} else if err != nil {
			return fmt.Errorf("error cleaning exif data: %w", err)
		}

		if err := storage.SaveFrom(target_storage, obj.CustomAvatarRelativePath(), func(w io.Writer) error {
			_, err := io.Copy(w, cleanedData)
			return err
		}); err != nil {
			if !strings.Contains(err.Error(), "unparseable undefined tag") {
				return fmt.Errorf("Failed to create dir %s: %w", obj.CustomAvatarRelativePath(), err)
			}
		}

		log.Info("... completed %s.", name)

		return nil
	}

	err := db.Iterate(ctx, nil, func(ctx context.Context, user *user_model.User) error {
		return doExifStrip(user, fmt.Sprintf("user %s", user.Name), storage.Avatars)
	})
	if err != nil {
		return err
	}

	err = db.Iterate(ctx, nil, func(ctx context.Context, repo *repo_model.Repository) error {
		return doExifStrip(repo, fmt.Sprintf("repo %s", repo.Name), storage.RepoAvatars)
	})
	if err != nil {
		return err
	}

	return nil
}

func runCleanupCommitStatus(ctx context.Context, cli *cli.Command) error {
	ctx, cancel := installSignals(ctx)
	defer cancel()

	if err := initDB(ctx); err != nil {
		return err
	}

	bufferSize := cli.Int("buffer-size")
	deleteChunkSize := cli.Int("delete-chunk-size")
	dryRun := cli.Bool("dry-run")
	log.Debug("bufferSize = %d, deleteChunkSize = %d, dryRun = %v", bufferSize, deleteChunkSize, dryRun)

	return git_model.CleanupCommitStatus(ctx, bufferSize, deleteChunkSize, dryRun)
}
