// Copyright 2023 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT

package cmd

import (
	"fmt"
	"os"
	"reflect"
	"strings"

	"code.gitea.io/gitea/modules/log"
	"code.gitea.io/gitea/modules/setting"

	"github.com/urfave/cli/v2"
)

// cmdHelp is our own help subcommand with more information
func cmdHelp() *cli.Command {
	c := &cli.Command{
		Name:      "help",
		Aliases:   []string{"h"},
		Usage:     "Shows a list of commands or help for one command",
		ArgsUsage: "[command]",
		Action: func(c *cli.Context) (err error) {
			args := c.Args()
			if args.Present() {
				err = cli.ShowCommandHelp(c, args.First())
			} else {
				err = cli.ShowAppHelp(c)
			}
			_, _ = fmt.Fprintf(c.App.Writer, `
DEFAULT CONFIGURATION:
   AppPath:    %s
   WorkPath:   %s
   CustomPath: %s
   ConfigFile: %s

`, setting.AppPath, setting.AppWorkPath, setting.CustomPath, setting.CustomConf)
			return err
		},
	}
	return c
}

var helpFlag = cli.HelpFlag

func init() {
	// cli.HelpFlag = nil TODO: after https://github.com/urfave/cli/issues/1794 we can use this
}

func appGlobalFlags() []cli.Flag {
	return []cli.Flag{
		// make the builtin flags at the top
		helpFlag,
		cli.VersionFlag,

		// shared configuration flags, they are for global and for each sub-command at the same time
		// eg: such command is valid: "./gitea --config /tmp/app.ini web --config /tmp/app.ini", while it's discouraged indeed
		// keep in mind that the short flags like "-C", "-c" and "-w" are globally polluted, they can't be used for sub-commands anymore.
		&cli.StringFlag{
			Name:    "custom-path",
			Aliases: []string{"C"},
			Usage:   "Set custom path (defaults to '{WorkPath}/custom')",
		},
		&cli.StringFlag{
			Name:    "config",
			Aliases: []string{"c"},
			Value:   setting.CustomConf,
			Usage:   "Set custom config file (defaults to '{WorkPath}/custom/conf/app.ini')",
		},
		&cli.StringFlag{
			Name:    "work-path",
			Aliases: []string{"w"},
			Usage:   "Set Gitea's working path (defaults to the Gitea's binary directory)",
		},
	}
}

func prepareSubcommandWithConfig(command *cli.Command, globalFlags []cli.Flag) {
	command.Flags = append(append([]cli.Flag{}, globalFlags...), command.Flags...)
	command.Action = prepareWorkPathAndCustomConf(command.Action)
	command.HideHelp = true
	if command.Name != "help" {
		command.Subcommands = append(command.Subcommands, cmdHelp())
	}
	for i := range command.Subcommands {
		prepareSubcommandWithConfig(command.Subcommands[i], globalFlags)
	}
}

// prepareWorkPathAndCustomConf wraps the Action to prepare the work path and custom config
// It can't use "Before", because each level's sub-command's Before will be called one by one, so the "init" would be done multiple times
func prepareWorkPathAndCustomConf(action cli.ActionFunc) func(ctx *cli.Context) error {
	return func(ctx *cli.Context) error {
		var args setting.ArgWorkPathAndCustomConf
		ctxLineage := ctx.Lineage()
		for i := len(ctxLineage) - 1; i >= 0; i-- {
			curCtx := ctxLineage[i]
			if curCtx.IsSet("work-path") && args.WorkPath == "" {
				args.WorkPath = curCtx.String("work-path")
			}
			if curCtx.IsSet("custom-path") && args.CustomPath == "" {
				args.CustomPath = curCtx.String("custom-path")
			}
			if curCtx.IsSet("config") && args.CustomConf == "" {
				args.CustomConf = curCtx.String("config")
			}
		}
		setting.InitWorkPathAndCommonConfig(os.Getenv, args)
		if ctx.Bool("help") || action == nil {
			// the default behavior of "urfave/cli": "nil action" means "show help"
			return cmdHelp().Action(ctx)
		}
		return action(ctx)
	}
}

func reflectGet(v any, fieldName string) any {
	e := reflect.ValueOf(v).Elem()
	return e.FieldByName(fieldName).Interface()
}

// https://cli.urfave.org/migrate-v1-to-v2/#flag-aliases-are-done-differently
// Sadly v2 doesn't warn you if a comma is in the name. (https://github.com/urfave/cli/issues/1103)
func checkCommandFlags(c any) bool {
	var cmds []*cli.Command
	if app, ok := c.(*cli.App); ok {
		cmds = app.Commands
	} else {
		cmds = c.(*cli.Command).Subcommands
	}
	ok := true
	for _, cmd := range cmds {
		for _, flag := range cmd.Flags {
			flagName := reflectGet(flag, "Name").(string)
			if strings.Contains(flagName, ",") {
				ok = false
				log.Error("cli.Flag can't have comma in its Name: %q, use Aliases instead", flagName)
			}
		}
		if !checkCommandFlags(cmd) {
			ok = false
		}
	}
	return ok
}

func NewMainApp() *cli.App {
	app := cli.NewApp()
	app.EnableBashCompletion = true

	// these sub-commands need to use config file
	subCmdWithConfig := []*cli.Command{
		CmdWeb,
		CmdServ,
		CmdHook,
		CmdDump,
		CmdAdmin,
		CmdMigrate,
		CmdKeys,
		CmdConvert,
		CmdDoctor,
		CmdManager,
		CmdEmbedded,
		CmdMigrateStorage,
		CmdDumpRepository,
		CmdRestoreRepository,
		CmdActions,
		cmdHelp(), // the "help" sub-command was used to show the more information for "work path" and "custom config"
	}

	// these sub-commands do not need the config file, and they do not depend on any path or environment variable.
	subCmdStandalone := []*cli.Command{
		CmdCert,
		CmdGenerate,
		CmdDocs,
	}

	app.DefaultCommand = CmdWeb.Name

	globalFlags := appGlobalFlags()
	app.Flags = append(app.Flags, globalFlags...)
	app.HideHelp = true // use our own help action to show helps (with more information like default config)
	app.Before = PrepareConsoleLoggerLevel(log.INFO)
	for i := range subCmdWithConfig {
		prepareSubcommandWithConfig(subCmdWithConfig[i], globalFlags)
	}
	app.Commands = append(app.Commands, subCmdWithConfig...)
	app.Commands = append(app.Commands, subCmdStandalone...)

	if !checkCommandFlags(app) {
		panic("some flags are incorrect") // this is a runtime check to help developers
	}
	return app
}