package api

import (
	"context"
	"math/rand"
	"net/http"
	"os"
	"os/signal"
	"time"

	"github.com/gin-gonic/gin"
	"github.com/go-sql-driver/mysql"
	"gitlab.celogeek.com/photos/api/internal/photoserrors"
	"gitlab.celogeek.com/photos/api/internal/store"
	"gorm.io/gorm"
)

type Service struct {
	Gin    *gin.Engine
	DB     *gorm.DB
	Config *ServiceConfig
	Store  *store.Store
	LogOk  *Logger
	LogErr *Logger
}

type ServiceConfig struct {
	Listen    string
	DB        *mysql.Config
	StorePath string
}

func New(config *ServiceConfig) *Service {
	return &Service{
		Gin:    gin.New(),
		Config: config,
		Store:  &store.Store{Path: config.StorePath},
		LogOk:  &Logger{os.Stdout, "Photos"},
		LogErr: &Logger{os.Stderr, "Photos"},
	}
}

func (s *Service) SetupRoutes() {
	s.Gin.Use(gin.Logger())
	s.Gin.Use(s.Recovery)
	s.Gin.Use(s.RequireBody)

	ac := s.Gin.Group("/account")
	ac.POST("/signup", s.Signup)
	ac.POST("/login", s.Login)
	ac.GET("/logout", s.RequireAuthToken, s.Logout)

	s.Gin.GET("/me", s.RequireSession, func(c *gin.Context) {
		c.JSON(http.StatusOK, gin.H{
			"status": "success",
			"user":   s.CurrentSession(c).Account.Login,
		})
	})

	file := s.Gin.Group("/file")
	file.Use(s.RequireSession)
	file.POST("", s.FileCreate)
	file.HEAD("/:checksum", s.FileExists)
	file.GET("/:checksum", s.FileGet)

	file.POST("/chunk", s.FileCreateChunk)
	file.HEAD("/chunk/:checksum", s.FileChunkExists)

	file.GET("/analyze/:checksum", s.FileAnalyze)

	s.Gin.NoRoute(func(c *gin.Context) {
		s.Error(c, http.StatusNotFound, photoserrors.ErrReqNotFound)
	})
}

func (s *Service) PrepareStore() {
	d, err := os.Stat(s.Store.Path)
	if err != nil {
		s.LogErr.Fatal("Store", err)
	}
	if !d.IsDir() {
		s.LogErr.Fatal("Store", photoserrors.ErrStorePathNotADirectory)
	}
}

func (s *Service) Run() error {
	rand.Seed(time.Now().UnixNano())
	s.PrepareStore()
	s.SetupRoutes()
	s.SetupDB()
	go s.SessionCleaner()

	srv := &http.Server{
		Addr:    s.Config.Listen,
		Handler: s.Gin,
	}

	quit := make(chan os.Signal, 1)
	var runError error
	go func() {
		// service connections
		if runError = srv.ListenAndServe(); runError != nil {
			quit <- os.Interrupt
		}
	}()

	// Wait for interrupt signal to gracefully shutdown the server with
	// a timeout of 5 seconds.
	signal.Notify(quit, os.Interrupt)
	<-quit
	s.LogOk.Print("Exit", "shutdown ...")

	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()
	if err := srv.Shutdown(ctx); err != nil {
		return err
	}

	db, err := s.DB.DB()
	if err != nil {
		return err
	}
	s.LogOk.Print("Exit", "closing database ...")
	if err := db.Close(); err != nil {
		return err
	}

	s.LogOk.Print("Exit", "exiting")
	return runError
}