// Copyright 2014 The Gogs Authors. All rights reserved.
// Copyright 2021 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT

package install

import (
	"net/http"
	"net/mail"
	"os"
	"os/exec"
	"path/filepath"
	"regexp"
	"slices"
	"strconv"
	"strings"
	"time"

	audit_model "gitea.dev/models/audit"
	"gitea.dev/models/db"
	db_install "gitea.dev/models/db/install"
	user_model "gitea.dev/models/user"
	"gitea.dev/modules/generate"
	"gitea.dev/modules/graceful"
	"gitea.dev/modules/log"
	"gitea.dev/modules/optional"
	"gitea.dev/modules/session"
	"gitea.dev/modules/setting"
	"gitea.dev/modules/templates"
	"gitea.dev/modules/timeutil"
	"gitea.dev/modules/web"
	"gitea.dev/modules/web/middleware"
	"gitea.dev/routers/common"
	"gitea.dev/services/audit"
	auth_service "gitea.dev/services/auth"
	"gitea.dev/services/context"
	"gitea.dev/services/forms"
	"gitea.dev/services/versioned_migration"
)

const (
	tplInstall     templates.TplName = "install"
	tplPostInstall templates.TplName = "post-install"
)

// getSupportedDbTypeNames returns a slice for supported database types and names. The slice is used to keep the order
func getSupportedDbTypeNames() (dbTypeNames []map[string]string) {
	for _, t := range setting.SupportedDatabaseTypes {
		dbTypeNames = append(dbTypeNames, map[string]string{"type": t, "name": setting.DatabaseTypeNames[t]})
	}
	return dbTypeNames
}

func installContexter() func(next http.Handler) http.Handler {
	return context.ContexterInstallPage(map[string]any{
		"DbTypeNames":    getSupportedDbTypeNames(),
		"EnvConfigKeys":  setting.CollectEnvConfigKeys(),
		"CustomConfFile": setting.CustomConf,
	})
}

// Install render installation page
func Install(ctx *context.Context) {
	if setting.InstallLock {
		InstallDone(ctx)
		return
	}

	form := forms.InstallForm{}

	// Database settings
	form.DbHost = setting.Database.Host
	form.DbUser = setting.Database.User
	form.DbPasswd = setting.Database.Passwd
	form.DbName = setting.Database.Name
	form.DbPath = setting.Database.Path
	form.DbSchema = setting.Database.Schema
	form.SSLMode = setting.Database.SSLMode

	curDBType := string(setting.Database.Type)
	if !slices.Contains(setting.SupportedDatabaseTypes, curDBType) {
		curDBType = "mysql"
	}
	ctx.Data["CurDbType"] = curDBType

	// Application general settings
	form.AppName = setting.AppName
	form.AppDataPath = setting.AppDataPath
	form.RunUser = setting.RunUser
	form.SSHPort = setting.SSH.Port
	form.HTTPPort = setting.HTTPPort
	form.AppURL = setting.AppURL

	// E-mail service settings
	if setting.MailService != nil {
		form.SMTPAddr = setting.MailService.SMTPAddr
		form.SMTPPort = setting.MailService.SMTPPort
		form.SMTPFrom = setting.MailService.From
		form.SMTPUser = setting.MailService.User
		form.SMTPPasswd = setting.MailService.Passwd
	}
	form.RegisterConfirm = setting.Service.RegisterEmailConfirm
	form.MailNotify = setting.Service.EnableNotifyMail
	form.EnableUpdateChecker = setting.CfgProvider.Section("cron.update_checker").Key("ENABLED").MustBool(true)

	form.DisableRegistration = setting.Service.DisableRegistration
	form.EnableCaptcha = setting.Service.EnableCaptcha
	form.RequireSignInView = setting.Service.RequireSignInViewStrict
	form.DefaultKeepEmailPrivate = setting.Service.DefaultKeepEmailPrivate
	form.DefaultAllowCreateOrganization = setting.Service.DefaultAllowCreateOrganization
	form.NoReplyAddress = setting.Service.NoReplyAddress

	middleware.AssignForm(form, ctx.Data)
	ctx.HTML(http.StatusOK, tplInstall)
}

func checkDatabase(ctx *context.Context, form *forms.InstallForm) bool {
	if setting.Database.Type.IsSQLite3() && setting.Database.Path == "" {
		ctx.Data["Err_DbPath"] = true
		ctx.RenderWithErrDeprecated(ctx.Tr("install.err_empty_db_path"), tplInstall, form)
		return false
	}

	// Check if the user is trying to re-install in an installed database
	db.UnsetDefaultEngine()
	defer db.UnsetDefaultEngine()

	if err := db.InitEngine(ctx); err != nil {
		ctx.Data["Err_DbSetting"] = true
		ctx.RenderWithErrDeprecated(ctx.Tr("install.invalid_db_setting", err), tplInstall, form)
		return false
	}

	err := db_install.CheckDatabaseConnection(ctx)
	if err != nil {
		ctx.Data["Err_DbSetting"] = true
		ctx.RenderWithErrDeprecated(ctx.Tr("install.invalid_db_setting", err), tplInstall, form)
		return false
	}

	hasPostInstallationUser, err := db_install.HasPostInstallationUsers(ctx)
	if err != nil {
		ctx.Data["Err_DbSetting"] = true
		ctx.RenderWithErrDeprecated(ctx.Tr("install.invalid_db_table", "user", err), tplInstall, form)
		return false
	}
	dbMigrationVersion, err := db_install.GetMigrationVersion(ctx)
	if err != nil {
		ctx.Data["Err_DbSetting"] = true
		ctx.RenderWithErrDeprecated(ctx.Tr("install.invalid_db_table", "version", err), tplInstall, form)
		return false
	}

	if hasPostInstallationUser && dbMigrationVersion > 0 {
		log.Error("The database is likely to have been used by Gitea before, database migration version=%d", dbMigrationVersion)
		confirmed := form.ReinstallConfirmFirst && form.ReinstallConfirmSecond && form.ReinstallConfirmThird
		if !confirmed {
			ctx.Data["Err_DbInstalledBefore"] = true
			ctx.RenderWithErrDeprecated(ctx.Tr("install.reinstall_error"), tplInstall, form)
			return false
		}

		log.Info("User confirmed re-installation of Gitea into a pre-existing database")
	}

	if hasPostInstallationUser {
		// non-empty user table
		if form.AdminName != "" {
			ctx.Data["Err_Admin"] = true
			ctx.RenderWithErrDeprecated(ctx.Tr("install.admin_user_recreation_disallowed"), tplInstall, form)
			return false
		}
	} else {
		// empty user table, check logic loophole between disable self-registration and no admin account.
		if form.DisableRegistration && form.AdminName == "" {
			ctx.Data["Err_Admin"] = true
			ctx.RenderWithErrDeprecated(ctx.Tr("install.no_admin_and_disable_registration"), tplInstall, form)
			return false
		}
	}

	if hasPostInstallationUser || dbMigrationVersion > 0 {
		log.Info("Gitea will be installed in a database with: hasPostInstallationUser=%v, dbMigrationVersion=%v", hasPostInstallationUser, dbMigrationVersion)
	}

	return true
}

// SubmitInstall response for submit install items
func SubmitInstall(ctx *context.Context) {
	if setting.InstallLock {
		InstallDone(ctx)
		return
	}

	form := web.GetForm[*forms.InstallForm](ctx)

	// fix form values
	if form.AppURL != "" && form.AppURL[len(form.AppURL)-1] != '/' {
		form.AppURL += "/"
	}

	ctx.Data["CurDbType"] = form.DbType

	if ctx.HasError() {
		ctx.Data["Err_SMTP"] = ctx.Data["Err_SMTPUser"] != nil
		ctx.Data["Err_Admin"] = ctx.Data["Err_AdminName"] != nil || ctx.Data["Err_AdminPasswd"] != nil || ctx.Data["Err_AdminEmail"] != nil
		ctx.HTML(http.StatusOK, tplInstall)
		return
	}

	if _, err := exec.LookPath("git"); err != nil {
		ctx.RenderWithErrDeprecated(ctx.Tr("install.test_git_failed", err), tplInstall, form)
		return
	}

	// ---- Basic checks are passed, now test configuration.

	// Test database setting.
	setting.Database.Type = setting.DatabaseType(form.DbType)
	setting.Database.Host = form.DbHost
	setting.Database.User = form.DbUser
	setting.Database.Passwd = form.DbPasswd
	setting.Database.Name = form.DbName
	setting.Database.Schema = form.DbSchema
	setting.Database.SSLMode = form.SSLMode
	setting.Database.Path = form.DbPath
	setting.Database.LogSQL = !setting.IsProd

	// Prepare AppDataPath, it is very important for Gitea
	// old code replaced "\\" to "/", it's questionable whether it's worth to do so
	form.AppDataPath = strings.ReplaceAll(form.AppDataPath, "\\", "/")
	setting.AppDataPath = form.AppDataPath
	if err := setting.PrepareAppDataPath(); err != nil {
		ctx.RenderWithErrDeprecated(ctx.Tr("install.invalid_app_data_path", err), tplInstall, form)
		return
	}

	if !checkDatabase(ctx, form) {
		return
	}

	// Check admin user creation
	if form.AdminName != "" {
		// Ensure AdminName is valid
		if err := user_model.IsUsableUsername(form.AdminName); err != nil {
			ctx.Data["Err_Admin"] = true
			ctx.Data["Err_AdminName"] = true
			if db.IsErrNameReserved(err) {
				ctx.RenderWithErrDeprecated(ctx.Tr("install.err_admin_name_is_reserved"), tplInstall, form)
				return
			} else if db.IsErrNamePatternNotAllowed(err) {
				ctx.RenderWithErrDeprecated(ctx.Tr("install.err_admin_name_pattern_not_allowed"), tplInstall, form)
				return
			}
			ctx.RenderWithErrDeprecated(ctx.Tr("install.err_admin_name_is_invalid"), tplInstall, form)
			return
		}
		// Check Admin email
		if len(form.AdminEmail) == 0 {
			ctx.Data["Err_Admin"] = true
			ctx.Data["Err_AdminEmail"] = true
			ctx.RenderWithErrDeprecated(ctx.Tr("install.err_empty_admin_email"), tplInstall, form)
			return
		}
		// Check admin password.
		if len(form.AdminPasswd) == 0 {
			ctx.Data["Err_Admin"] = true
			ctx.Data["Err_AdminPasswd"] = true
			ctx.RenderWithErrDeprecated(ctx.Tr("install.err_empty_admin_password"), tplInstall, form)
			return
		}
		if form.AdminPasswd != form.AdminConfirmPasswd {
			ctx.Data["Err_Admin"] = true
			ctx.Data["Err_AdminPasswd"] = true
			ctx.RenderWithErrDeprecated(ctx.Tr("form.password_not_match"), tplInstall, form)
			return
		}
	}

	// Init the engine with migration
	if err := db.InitEngineWithMigration(ctx, versioned_migration.Migrate); err != nil {
		db.UnsetDefaultEngine()
		ctx.Data["Err_DbSetting"] = true
		ctx.RenderWithErrDeprecated(ctx.Tr("install.invalid_db_setting", err), tplInstall, form)
		return
	}

	cfg := fillInstallConfig(ctx, os.Environ(), form)
	if cfg == nil {
		return
	}
	if !saveConfigReinitDB(ctx, cfg, form) {
		return
	}
	if !initAdminUser(ctx, form) {
		return
	}

	InstallDone(ctx) // render the "install done" page
	restartServer(ctx)
}

func fillInstallConfig(ctx *context.Context, envs []string, form *forms.InstallForm) setting.ConfigProvider {
	// Some logic also depends on the config values, so EnvironmentToConfig should also be applied first.
	// EnvironmentToConfig is applied on each start up, so it also must override the "install form", so it must be applied after (twice).
	cfg, err := setting.NewConfigProviderFromFile(setting.CustomConf)
	if err != nil {
		log.Error("Failed to load custom conf '%s': %v", setting.CustomConf, err)
	}

	setting.EnvironmentToConfig(cfg, envs)
	cfg.Section("").Key("RUN_MODE").SetValue("prod")
	cfg.Section("security").Key("INSTALL_LOCK").SetValue("true")

	cfg.Section("").Key("APP_NAME").SetValue(form.AppName)
	cfg.Section("").Key("RUN_USER").SetValue(form.RunUser)
	cfg.Section("").Key("WORK_PATH").SetValue(setting.AppWorkPath)

	cfg.Section("database").Key("DB_TYPE").SetValue(string(setting.Database.Type))
	cfg.Section("database").Key("HOST").SetValue(setting.Database.Host)
	cfg.Section("database").Key("NAME").SetValue(setting.Database.Name)
	cfg.Section("database").Key("USER").SetValue(setting.Database.User)
	cfg.Section("database").Key("PASSWD").SetValue(setting.Database.Passwd)
	cfg.Section("database").Key("SCHEMA").SetValue(setting.Database.Schema)
	cfg.Section("database").Key("SSL_MODE").SetValue(setting.Database.SSLMode)
	cfg.Section("database").Key("PATH").SetValue(setting.Database.Path)

	cfg.Section("server").Key("HTTP_PORT").SetValue(form.HTTPPort)
	cfg.Section("server").Key("ROOT_URL").SetValue(form.AppURL)
	cfg.Section("server").Key("APP_DATA_PATH").SetValue(form.AppDataPath)
	cfg.Section("server").Key("LFS_START_SERVER").SetValue("true")
	if !cfg.Section("server").HasKey("LFS_JWT_SECRET_URI") {
		_, lfsJwtSecret := generate.NewJwtSecretWithBase64()
		cfg.Section("server").Key("LFS_JWT_SECRET").SetValue(lfsJwtSecret)
	}

	if form.SSHPort == 0 {
		cfg.Section("server").Key("DISABLE_SSH").SetValue("true")
	} else {
		cfg.Section("server").Key("DISABLE_SSH").SetValue("false")
		cfg.Section("server").Key("SSH_PORT").SetValue(strconv.Itoa(form.SSHPort))
	}

	if form.SMTPAddr != "" {
		if _, err := mail.ParseAddress(form.SMTPFrom); err != nil {
			ctx.RenderWithErrDeprecated(ctx.Tr("install.smtp_from_invalid"), tplInstall, form)
			return nil
		}

		cfg.Section("mailer").Key("ENABLED").SetValue("true")
		cfg.Section("mailer").Key("SMTP_ADDR").SetValue(form.SMTPAddr)
		cfg.Section("mailer").Key("SMTP_PORT").SetValue(form.SMTPPort)
		cfg.Section("mailer").Key("FROM").SetValue(form.SMTPFrom)
		cfg.Section("mailer").Key("USER").SetValue(form.SMTPUser)
		cfg.Section("mailer").Key("PASSWD").SetValue(form.SMTPPasswd)
	} else {
		cfg.Section("mailer").Key("ENABLED").SetValue("false")
	}
	cfg.Section("service").Key("REGISTER_EMAIL_CONFIRM").SetValue(strconv.FormatBool(form.RegisterConfirm))
	cfg.Section("service").Key("ENABLE_NOTIFY_MAIL").SetValue(strconv.FormatBool(form.MailNotify))

	cfg.Section("service").Key("DISABLE_REGISTRATION").SetValue(strconv.FormatBool(form.DisableRegistration))
	cfg.Section("service").Key("ENABLE_CAPTCHA").SetValue(strconv.FormatBool(form.EnableCaptcha))
	cfg.Section("service").Key("REQUIRE_SIGNIN_VIEW").SetValue(strconv.FormatBool(form.RequireSignInView))
	cfg.Section("service").Key("DEFAULT_KEEP_EMAIL_PRIVATE").SetValue(strconv.FormatBool(form.DefaultKeepEmailPrivate))
	cfg.Section("service").Key("DEFAULT_ALLOW_CREATE_ORGANIZATION").SetValue(strconv.FormatBool(form.DefaultAllowCreateOrganization))
	cfg.Section("service").Key("NO_REPLY_ADDRESS").SetValue(form.NoReplyAddress)

	cfg.Section("cron.update_checker").Key("ENABLED").SetValue(strconv.FormatBool(form.EnableUpdateChecker))

	cfg.Section("repository.signing").Key("DEFAULT_TRUST_MODEL").SetValue("committer")

	// the internal token could be read from INTERNAL_TOKEN or INTERNAL_TOKEN_URI (the file is guaranteed to be non-empty)
	// if there is no InternalToken, generate one and save to security.INTERNAL_TOKEN
	if setting.InternalToken == "" {
		var internalToken string
		if internalToken, err = generate.NewInternalToken(); err != nil {
			ctx.RenderWithErrDeprecated(ctx.Tr("install.internal_token_failed", err), tplInstall, form)
			return nil
		}
		cfg.Section("security").Key("INTERNAL_TOKEN").SetValue(internalToken)
	}

	// FIXME: at the moment, no matter oauth2 is enabled or not, it must generate a "oauth2 JWT_SECRET"
	// see the "loadOAuth2From" in "setting/oauth2.go"
	if !cfg.Section("oauth2").HasKey("JWT_SECRET") && !cfg.Section("oauth2").HasKey("JWT_SECRET_URI") {
		_, jwtSecretBase64 := generate.NewJwtSecretWithBase64()
		cfg.Section("oauth2").Key("JWT_SECRET").SetValue(jwtSecretBase64)
	}

	// if there is already a SECRET_KEY, we should not overwrite it, otherwise the encrypted data will not be able to be decrypted
	if setting.SecretKey == "" {
		var secretKey string
		if secretKey, err = generate.NewSecretKey(); err != nil {
			ctx.RenderWithErrDeprecated(ctx.Tr("install.secret_key_failed", err), tplInstall, form)
			return nil
		}
		cfg.Section("security").Key("SECRET_KEY").SetValue(secretKey)
	}

	setting.EnvironmentToConfig(cfg, envs)
	fillInstallConfigCleanUp(cfg)
	return cfg
}

func fillInstallConfigCleanUp(cfg setting.ConfigProvider) {
	// this is just a quick patch to avoid generating a corrupted ini file,
	// if there would be no bug for ini handling (e.g.: we write our package), this patch is not needed.
	re := regexp.MustCompile(`[\x00-\x1F\x7F]`)
	for _, sec := range cfg.Sections() {
		for _, key := range sec.Keys() {
			s := key.String()
			s = re.ReplaceAllString(s, " ")
			key.SetValue(s)
		}
	}
}

func saveConfigReinitDB(ctx *context.Context, cfg setting.ConfigProvider, form *forms.InstallForm) bool {
	log.Info("Save settings to custom config file %s", setting.CustomConf)

	err := os.MkdirAll(filepath.Dir(setting.CustomConf), os.ModePerm)
	if err != nil {
		ctx.RenderWithErrDeprecated(ctx.Tr("install.save_config_failed", err), tplInstall, form)
		return false
	}

	if err := cfg.SaveTo(setting.CustomConf); err != nil {
		ctx.RenderWithErrDeprecated(ctx.Tr("install.save_config_failed", err), tplInstall, form)
		return false
	}

	// unset default engine before reload database setting
	db.UnsetDefaultEngine()

	// Reload settings (and re-initialize database connection)
	setting.InitCfgProvider(setting.CustomConf)
	setting.LoadCommonSettings()
	setting.MustInstalled()
	setting.LoadDBSetting()
	if err := common.InitDBEngine(ctx); err != nil {
		log.Fatal("ORM engine initialization failed: %v", err)
	}

	setting.ClearEnvConfigKeys()
	log.Info("Installation completed! You can also use 'gitea admin user ...' sub-commands to create or edit admin users.")
	log.Info("----------------------------------------")
	return true
}

func initAdminUser(ctx *context.Context, form *forms.InstallForm) bool {
	if form.AdminName == "" {
		return true
	}

	adminUser := &user_model.User{
		Name:    form.AdminName,
		Email:   form.AdminEmail,
		Passwd:  form.AdminPasswd,
		IsAdmin: true,
	}
	overwriteDefault := &user_model.CreateUserOverwriteOptions{
		IsRestricted: optional.Some(false),
		IsActive:     optional.Some(true),
	}

	if err := user_model.CreateUser(ctx, adminUser, &user_model.Meta{}, overwriteDefault); err != nil {
		ctx.Data["Err_AdminName"] = true
		ctx.Data["Err_AdminEmail"] = true
		if user_model.IsErrUserAlreadyExist(err) {
			ctx.RenderWithErrDeprecated(ctx.Tr("install.admin_user_recreation_disallowed"), tplInstall, form)
		} else {
			ctx.RenderWithErrDeprecated(ctx.Tr("install.invalid_admin_setting", err), tplInstall, form)
		}
		return false
	}

	audit.RecordAs(ctx, adminUser, audit_model.UserCreate, adminUser)

	nt, token, err := auth_service.CreateAuthTokenForUserID(ctx, adminUser.ID)
	if err != nil {
		ctx.ServerError("CreateAuthTokenForUserID", err)
		return false
	}

	// Auto-login for admin, even if any "session" error happens, it should still continue
	ctx.SetSiteCookie(setting.CookieRememberName, nt.ID+":"+token, setting.LogInRememberDays*timeutil.Day)
	_ = ctx.Session.Set(session.KeyUID, adminUser.ID)
	_ = ctx.Session.Release()
	return true
}

func restartServer(ctx *context.Context) {
	// Now get the http.Server from this request and shut it down
	// NB: This is not our hammerable graceful shutdown this is http.Server.Shutdown
	srv, _ := ctx.Value(http.ServerContextKey).(*http.Server)

	go func() {
		// Sleep for a while to make sure the user's browser has loaded the post-install page and its assets (images, css, js)
		// What if this duration is not long enough? That's impossible -- if the user can't load the simple page in time, how could they install or use Gitea in the future ....
		time.Sleep(3 * time.Second)

		if err := srv.Shutdown(graceful.GetManager().HammerContext()); err != nil {
			log.Error("Unable to shutdown the install server! Error: %v", err)
		}

		// After the HTTP server for "install" shuts down, the `runWeb()` will continue to run the "normal" server
	}()
}

// InstallDone shows the "post-install" page, makes it easier to develop the page.
// The name is not called as "PostInstall" to avoid misinterpretation as a handler for "POST /install"
func InstallDone(ctx *context.Context) { //nolint:revive // export stutter
	hasUsers, _ := user_model.HasUsers(ctx)
	ctx.Data["IsAccountCreated"] = hasUsers.HasAnyUser
	ctx.HTML(http.StatusOK, tplPostInstall)
}