package ldapLogin

import (
	"fmt"
	"github.com/go-ldap/ldap/v3"
	"github.com/labstack/echo/v5"
	"github.com/pocketbase/pocketbase"
	"github.com/pocketbase/pocketbase/apis"
	"github.com/pocketbase/pocketbase/core"
	"gitlab.uni-ulm.de/stuve-it/it-tools/backend/ldapSync"
	"gitlab.uni-ulm.de/stuve-it/it-tools/backend/logger"
	"os"
)

// InitLDAPLogin initializes ldap login endpoint
//
// this endpoint is used to authenticate users against ldap server
// it adds the following endpoint to the app:
// GET /api/ldap/login
//
// the endpoint expects the following request data:
//
//	{
//	  "cn": "user common name",
//	  "password": "user password"
//	}
//
// if the user is authenticated successfully the endpoint returns and apis.RecordAuthResponse
func InitLDAPLogin(app *pocketbase.PocketBase, e *core.ServeEvent) error {

	// add endpoint to app
	logger.LogInfoF("Adding LDAP Login Endpoint")

	e.Router.POST("/api/ldap/login", func(c echo.Context) error {

		logger.LogInfoF("LDAP Login")

		// step 1: get data from request
		data := struct {
			Username string `json:"username" form:"username"`
			Password string `json:"password" form:"password"`
		}{}
		if err := c.Bind(&data); err != nil {
			return apis.NewBadRequestError("Failed to read request data", err)
		}

		// step 2: get ldap user by cn from ldapUsers table
		record, err := ldapSync.GetLdapUserByCN(app, data.Username)

		// if user does not exist in ldapUsers table return error
		if err != nil {
			return apis.NewBadRequestError("Invalid credentials", err)
		}

		// step 3: connect to ldap server
		conn, err := ldap.DialURL(os.Getenv("LDAP_URL"))
		if err != nil {
			return apis.NewBadRequestError(
				"Failed to read request data",
				fmt.Errorf("unable to connect to ldap server - %s", err),
			)
		}
		defer conn.Close()

		// step 4: bind to ldap server with user credentials from request
		err = conn.Bind(data.Username, data.Password)
		if err != nil {
			// if bind fails return error - invalid credentials
			return apis.NewBadRequestError("Invalid credentials", err)
		}

		// return auth response
		return apis.RecordAuthResponse(app, c, record, nil)
	}, apis.ActivityLogger(app))

	return nil
}