package handler

import (
	"log"
	"net/http"
	"time"

	"github.com/drone/drone/plugin/remote"
	"github.com/drone/drone/server/database"
	"github.com/drone/drone/server/session"
	"github.com/drone/drone/shared/model"
	"github.com/gorilla/pat"
)

type LoginHandler struct {
	users database.UserManager
	repos database.RepoManager
	perms database.PermManager
	sess  session.Session
	open  bool
}

func NewLoginHandler(users database.UserManager, repos database.RepoManager, perms database.PermManager, sess session.Session, open bool) *LoginHandler {
	return &LoginHandler{users, repos, perms, sess, open}
}

// GetLogin gets the login to the 3rd party remote system.
// GET /login/:host
func (h *LoginHandler) GetLogin(w http.ResponseWriter, r *http.Request) error {
	var host = r.FormValue(":host")
	var redirect = "/"
	var remote = remote.Lookup(host)
	if remote == nil {
		return notFound{}
	}

	// authenticate the user
	login, err := remote.Authorize(w, r)
	if err != nil {
		return badRequest{err}
	} else if login == nil {
		// in this case we probably just redirected
		// the user, so we can exit with no error
		return nil
	}

	// get the user from the database
	u, err := h.users.FindLogin(host, login.Login)
	if err != nil {
		// if self-registration is disabled we should
		// return a notAuthorized error. the only exception
		// is if no users exist yet in the system we'll proceed.
		if h.open == false && h.users.Exist() {
			return notAuthorized{}
		}

		// create the user account
		u = model.NewUser(remote.GetKind(), login.Login, login.Email)
		u.Name = login.Name
		u.SetEmail(login.Email)

		// insert the user into the database
		if err := h.users.Insert(u); err != nil {
			return badRequest{err}
		}

		// if this is the first user, they
		// should be an admin.
		if u.ID == 1 {
			u.Admin = true
		}
	}

	// update the user access token
	// in case it changed in GitHub
	u.Access = login.Access
	u.Secret = login.Secret
	u.Name = login.Name
	u.SetEmail(login.Email)
	u.Syncing = true //u.IsStale() // todo (badrydzewski) should not always sync
	if err := h.users.Update(u); err != nil {
		return badRequest{err}
	}

	// look at the last synchronized date to determine if
	// we need to re-sync the account.
	//
	// todo(bradrydzewski) this should move to a server/sync package and
	//      should be injected into this struct, just like the database code.
	//
	// todo(bradrydzewski) this login should be a bit more intelligent
	//      than the current implementation.
	//
	// todo(bradrydzewski) the github implementation will only sync a
	//      maximum of 100 repositories due to the api pagination. need to fix.
	if u.Syncing {
		redirect = "/sync"
		log.Println("sync user account.", u.Login)

		// sync inside a goroutine. This should eventually be moved to
		// its own package / sync utility.
		go func() {
			repos, err := remote.GetRepos(u)
			if err != nil {
				log.Println("Error syncing user account, listing repositories", u.Login, err)
				return
			}

			// insert all repositories
			for _, repo := range repos {
				var role = repo.Role
				if err := h.repos.Insert(repo); err != nil {
					// typically we see a failure because the repository already exists
					// in which case, we can retrieve the existing record to get the ID.
					repo, err = h.repos.FindName(repo.Host, repo.Owner, repo.Name)
					if err != nil {
						log.Println("Error adding repo.", u.Login, repo.Name, err)
						continue
					}
				}

				// add user permissions
				if err := h.perms.Grant(u, repo, role.Read, role.Write, role.Admin); err != nil {
					log.Println("Error adding permissions.", u.Login, repo.Name, err)
					continue
				}

				log.Println("Successfully syced repo.", u.Login+"/"+repo.Name)
			}

			u.Synced = time.Now().UTC().Unix()
			u.Syncing = false
			if err := h.users.Update(u); err != nil {
				log.Println("Error syncing user account, updating sync date", u.Login, err)
				return
			}
		}()
	}

	// (re)-create the user session
	h.sess.SetUser(w, r, u)

	// redirect the user to their dashboard
	http.Redirect(w, r, redirect, http.StatusSeeOther)
	return nil
}

// GetLogout terminates the current user session
// GET /logout
func (h *LoginHandler) GetLogout(w http.ResponseWriter, r *http.Request) error {
	h.sess.Clear(w, r)
	http.Redirect(w, r, "/login", http.StatusSeeOther)
	return nil
}

func (h *LoginHandler) Register(r *pat.Router) {
	r.Get("/login/{host}", errorHandler(h.GetLogin))
	r.Post("/login/{host}", errorHandler(h.GetLogin))
	r.Get("/logout", errorHandler(h.GetLogout))
}