package main

import (
	"encoding/json"
	"net/http"
	"regexp"
	"strings"
	"syscall"
	"time"

	"github.com/gofrs/uuid"
	"github.com/jmoiron/sqlx/types"
	"github.com/labstack/echo"
)

type settings struct {
	AppRootURL          string   `json:"app.root_url"`
	AppLogoURL          string   `json:"app.logo_url"`
	AppFaviconURL       string   `json:"app.favicon_url"`
	AppFromEmail        string   `json:"app.from_email"`
	AppNotifyEmails     []string `json:"app.notify_emails"`
	EnablePublicSubPage bool     `json:"app.enable_public_subscription_page"`
	AppLang             string   `json:"app.lang"`

	AppBatchSize     int `json:"app.batch_size"`
	AppConcurrency   int `json:"app.concurrency"`
	AppMaxSendErrors int `json:"app.max_send_errors"`
	AppMessageRate   int `json:"app.message_rate"`

	AppMessageSlidingWindow         bool   `json:"app.message_sliding_window"`
	AppMessageSlidingWindowDuration string `json:"app.message_sliding_window_duration"`
	AppMessageSlidingWindowRate     int    `json:"app.message_sliding_window_rate"`

	PrivacyIndividualTracking bool     `json:"privacy.individual_tracking"`
	PrivacyUnsubHeader        bool     `json:"privacy.unsubscribe_header"`
	PrivacyAllowBlocklist     bool     `json:"privacy.allow_blocklist"`
	PrivacyAllowExport        bool     `json:"privacy.allow_export"`
	PrivacyAllowWipe          bool     `json:"privacy.allow_wipe"`
	PrivacyExportable         []string `json:"privacy.exportable"`

	UploadProvider             string `json:"upload.provider"`
	UploadFilesystemUploadPath string `json:"upload.filesystem.upload_path"`
	UploadFilesystemUploadURI  string `json:"upload.filesystem.upload_uri"`
	UploadS3AwsAccessKeyID     string `json:"upload.s3.aws_access_key_id"`
	UploadS3AwsDefaultRegion   string `json:"upload.s3.aws_default_region"`
	UploadS3AwsSecretAccessKey string `json:"upload.s3.aws_secret_access_key,omitempty"`
	UploadS3Bucket             string `json:"upload.s3.bucket"`
	UploadS3BucketDomain       string `json:"upload.s3.bucket_domain"`
	UploadS3BucketPath         string `json:"upload.s3.bucket_path"`
	UploadS3BucketType         string `json:"upload.s3.bucket_type"`
	UploadS3Expiry             string `json:"upload.s3.expiry"`

	SMTP []struct {
		UUID          string              `json:"uuid"`
		Enabled       bool                `json:"enabled"`
		Host          string              `json:"host"`
		HelloHostname string              `json:"hello_hostname"`
		Port          int                 `json:"port"`
		AuthProtocol  string              `json:"auth_protocol"`
		Username      string              `json:"username"`
		Password      string              `json:"password,omitempty"`
		EmailHeaders  []map[string]string `json:"email_headers"`
		MaxConns      int                 `json:"max_conns"`
		MaxMsgRetries int                 `json:"max_msg_retries"`
		IdleTimeout   string              `json:"idle_timeout"`
		WaitTimeout   string              `json:"wait_timeout"`
		TLSEnabled    bool                `json:"tls_enabled"`
		TLSSkipVerify bool                `json:"tls_skip_verify"`
	} `json:"smtp"`

	Messengers []struct {
		UUID          string `json:"uuid"`
		Enabled       bool   `json:"enabled"`
		Name          string `json:"name"`
		RootURL       string `json:"root_url"`
		Username      string `json:"username"`
		Password      string `json:"password,omitempty"`
		MaxConns      int    `json:"max_conns"`
		Timeout       string `json:"timeout"`
		MaxMsgRetries int    `json:"max_msg_retries"`
	} `json:"messengers"`
}

var (
	reAlphaNum = regexp.MustCompile(`[^a-z0-9\-]`)
)

// handleGetSettings returns settings from the DB.
func handleGetSettings(c echo.Context) error {
	app := c.Get("app").(*App)

	s, err := getSettings(app)
	if err != nil {
		return err
	}

	// Empty out passwords.
	for i := 0; i < len(s.SMTP); i++ {
		s.SMTP[i].Password = ""
	}
	for i := 0; i < len(s.Messengers); i++ {
		s.Messengers[i].Password = ""
	}
	s.UploadS3AwsSecretAccessKey = ""

	return c.JSON(http.StatusOK, okResp{s})
}

// handleUpdateSettings returns settings from the DB.
func handleUpdateSettings(c echo.Context) error {
	var (
		app = c.Get("app").(*App)
		set settings
	)

	// Unmarshal and marshal the fields once to sanitize the settings blob.
	if err := c.Bind(&set); err != nil {
		return err
	}

	// Get the existing settings.
	cur, err := getSettings(app)
	if err != nil {
		return err
	}

	// There should be at least one SMTP block that's enabled.
	has := false
	for i, s := range set.SMTP {
		if s.Enabled {
			has = true
		}

		// Assign a UUID. The frontend only sends a password when the user explictly
		// changes the password. In other cases, the existing password in the DB
		// is copied while updating the settings and the UUID is used to match
		// the incoming array of SMTP blocks with the array in the DB.
		if s.UUID == "" {
			set.SMTP[i].UUID = uuid.Must(uuid.NewV4()).String()
		}

		// If there's no password coming in from the frontend, copy the existing
		// password by matching the UUID.
		if s.Password == "" {
			for _, c := range cur.SMTP {
				if s.UUID == c.UUID {
					set.SMTP[i].Password = c.Password
				}
			}
		}
	}
	if !has {
		return echo.NewHTTPError(http.StatusBadRequest, app.i18n.T("settings.errorNoSMTP"))
	}

	// Validate and sanitize postback Messenger names. Duplicates are disallowed
	// and "email" is a reserved name.
	names := map[string]bool{emailMsgr: true}

	for i, m := range set.Messengers {
		// UUID to keep track of password changes similar to the SMTP logic above.
		if m.UUID == "" {
			set.Messengers[i].UUID = uuid.Must(uuid.NewV4()).String()
		}

		if m.Password == "" {
			for _, c := range cur.Messengers {
				if m.UUID == c.UUID {
					set.Messengers[i].Password = c.Password
				}
			}
		}

		name := reAlphaNum.ReplaceAllString(strings.ToLower(m.Name), "")
		if _, ok := names[name]; ok {
			return echo.NewHTTPError(http.StatusBadRequest,
				app.i18n.Ts("settings.duplicateMessengerName", "name", name))
		}
		if len(name) == 0 {
			return echo.NewHTTPError(http.StatusBadRequest, app.i18n.T("settings.invalidMessengerName"))
		}

		set.Messengers[i].Name = name
		names[name] = true
	}

	// S3 password?
	if set.UploadS3AwsSecretAccessKey == "" {
		set.UploadS3AwsSecretAccessKey = cur.UploadS3AwsSecretAccessKey
	}

	// Marshal settings.
	b, err := json.Marshal(set)
	if err != nil {
		return echo.NewHTTPError(http.StatusInternalServerError,
			app.i18n.Ts("settings.errorEncoding", "error", err.Error()))
	}

	// Update the settings in the DB.
	if _, err := app.queries.UpdateSettings.Exec(b); err != nil {
		return echo.NewHTTPError(http.StatusInternalServerError,
			app.i18n.Ts("globals.messages.errorUpdating",
				"name", "{globals.terms.settings}", "error", pqErrMsg(err)))
	}

	// If there are any active campaigns, don't do an auto reload and
	// warn the user on the frontend.
	if app.manager.HasRunningCampaigns() {
		app.Lock()
		app.needsRestart = true
		app.Unlock()

		return c.JSON(http.StatusOK, okResp{struct {
			NeedsRestart bool `json:"needs_restart"`
		}{true}})
	}

	// No running campaigns. Reload the app.
	go func() {
		<-time.After(time.Millisecond * 500)
		app.sigChan <- syscall.SIGHUP
	}()

	return c.JSON(http.StatusOK, okResp{true})
}

// handleGetLogs returns the log entries stored in the log buffer.
func handleGetLogs(c echo.Context) error {
	app := c.Get("app").(*App)
	return c.JSON(http.StatusOK, okResp{app.bufLog.Lines()})
}

func getSettings(app *App) (settings, error) {
	var (
		b   types.JSONText
		out settings
	)

	if err := app.queries.GetSettings.Get(&b); err != nil {
		return out, echo.NewHTTPError(http.StatusInternalServerError,
			app.i18n.Ts("globals.messages.errorFetching",
				"name", "{globals.terms.settings}", "error", pqErrMsg(err)))
	}

	// Unmarshall the settings and filter out sensitive fields.
	if err := json.Unmarshal([]byte(b), &out); err != nil {
		return out, echo.NewHTTPError(http.StatusInternalServerError,
			app.i18n.Ts("settings.errorEncoding", "error", err.Error()))
	}

	return out, nil
}