// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
// See LICENSE.txt for license information.

package main

import (
	"flag"
	"fmt"
	"os"
	"slices"
	"strings"
	"text/template"

	"github.com/mattermost/mattermost/server/public/model"
	"github.com/mattermost/mattermost/server/v8/channels/app"
	"github.com/mattermost/mattermost/server/v8/channels/store/storetest"
	"github.com/mattermost/mattermost/server/v8/channels/utils"
	"github.com/mattermost/mattermost/server/v8/config"
)

type roleEntry struct {
	Name        string
	Permissions string
}

var tmpl = template.Must(template.New("").Parse(`// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
// See LICENSE.txt for license information.

// Code generated by generate_default_roles_permissions.go. DO NOT EDIT.

export const defaultRolesPermissions = {
{{- range .}}
    {{.Name}}: '{{.Permissions}}',
{{- end}}
};
`))

func main() {
	outPath := flag.String("out", "", "output file path")
	flag.Parse()

	if *outPath == "" {
		fmt.Fprintln(os.Stderr, "usage: generate_default_roles_permissions -out <path>")
		os.Exit(1)
	}

	if err := utils.TranslationsPreInit(); err != nil {
		fmt.Fprintf(os.Stderr, "warning: could not load translations: %v\n", err)
	}

	sqlSettings := storetest.MakeSqlSettings(model.DatabaseDriverPostgres)
	defer storetest.CleanupSqlSettings(sqlSettings)

	cfg := model.Config{}
	cfg.SetDefaults()
	cfg.SqlSettings = *sqlSettings

	memStore, err := config.NewMemoryStoreWithOptions(&config.MemoryStoreOptions{
		InitialConfig: &cfg,
	})
	if err != nil {
		fmt.Fprintf(os.Stderr, "error creating config store: %v\n", err)
		os.Exit(1)
	}
	cfgStore, err := config.NewStoreFromBacking(memStore, nil, false)
	if err != nil {
		fmt.Fprintf(os.Stderr, "error creating config store: %v\n", err)
		os.Exit(1)
	}

	// NewServer runs both schema migrations (via sqlstore.New) and all
	// app-level migrations (doAppMigrations) as part of its initialization.
	server, err := app.NewServer(app.ConfigStore(cfgStore))
	if err != nil {
		fmt.Fprintf(os.Stderr, "error creating server: %v\n", err)
		os.Exit(1)
	}
	defer server.Shutdown()

	roles, err := server.Store().Role().GetAll()
	if err != nil {
		fmt.Fprintf(os.Stderr, "error reading roles: %v\n", err)
		os.Exit(1)
	}

	defaultNames := make(map[string]bool, len(model.MakeDefaultRoles()))
	for name := range model.MakeDefaultRoles() {
		defaultNames[name] = true
	}

	var roleNames []string
	roleByName := make(map[string]*model.Role, len(roles))
	for _, r := range roles {
		if defaultNames[r.Name] {
			roleNames = append(roleNames, r.Name)
			roleByName[r.Name] = r
		}
	}
	slices.Sort(roleNames)

	entries := make([]roleEntry, 0, len(roleNames))
	for _, name := range roleNames {
		perms := make([]string, len(roleByName[name].Permissions))
		copy(perms, roleByName[name].Permissions)
		slices.Sort(perms)
		perms = slices.Compact(perms)
		entries = append(entries, roleEntry{
			Name:        name,
			Permissions: strings.Join(perms, " "),
		})
	}

	var b strings.Builder
	if err := tmpl.Execute(&b, entries); err != nil {
		fmt.Fprintf(os.Stderr, "error executing template: %v\n", err)
		os.Exit(1)
	}

	if err := os.WriteFile(*outPath, []byte(b.String()), 0644); err != nil {
		fmt.Fprintf(os.Stderr, "error writing %s: %v\n", *outPath, err)
		os.Exit(1)
	}

	fmt.Printf("Generated %s\n", *outPath)
}