package main

import (
	"fmt"
	"net/http"
	"strconv"

	"github.com/foolin/goview/supports/ginview"
	"github.com/gin-contrib/sessions"
	"github.com/gin-contrib/sessions/cookie"
	"github.com/gin-gonic/gin"
)

func main() {
	r := gin.Default()

	r.HTMLRender = ginview.Default()

	store := cookie.NewStore([]byte("secret"))
	r.Use(sessions.Sessions("mysession", store))

	r.StaticFile("/favicon.ico", "./assets/favicon.ico")
	r.StaticFile("/sgs.png", "./assets/sgs.png")
	r.StaticFile("/en.png", "./assets/en.png")
	r.StaticFile("/cross.png", "./assets/cross.png")
	r.StaticFile("/nought.png", "./assets/nought.png")

	r.GET("/", func(c *gin.Context) {
		lang := getLang(c)
		c.Redirect(http.StatusMovedPermanently, fmt.Sprintf("/%s/0/x", lang))
	})

	r.GET("/:lang", func(c *gin.Context) {
		lang := getLang(c)
		c.Redirect(http.StatusMovedPermanently, fmt.Sprintf("/%s/0/x", lang))
	})

	r.GET("/:lang/:ai_second/:game", func(c *gin.Context) {
		lang := getLang(c)
		gameFlow, gameState := getGameFlow(c)

		aiSecond, err := strconv.ParseBool(c.Param("ai_second"))
		if err != nil {
			aiSecond = false
		}

		game := newGame(gameFlow, aiSecond)

		if gameState == GameStateInProgress && !game.isFinished() {
			gameFlow = gameFlow + getNewClick(gameFlow)
			game = newGame(gameFlow, aiSecond)
		}

		// if game ended - save results

		c.HTML(http.StatusOK, "index", gin.H{
			"title":    "Index title!",
			"lang":     lang,
			"gameFlow": gameFlow,
			"game":     game,
			"fields":   [9]int{1, 2, 3, 4, 5, 6, 7, 8, 9},
			"fieldClass": func(game *Game, fieldNum int) string {
				fieldClass := FieldClass[fieldNum]
				if field, ok := game.fields[fieldNum]; ok {
					if len(field.image) > 0 {
						fieldClass = fieldClass + " " + field.image
					}
					if field.line {
						fieldClass = fieldClass + " line"
					}
				}

				return fieldClass
			},
			"disabled": func(game *Game, fieldNum int) bool {
				if field, ok := game.fields[fieldNum]; ok {
					return field.disabled
				}

				return false
			},
		})
	})

	r.Run()
}

func getLang(c *gin.Context) string {
	session := sessions.Default(c)

	lang := session.Get("lang").(string)
	pLang, hasParam := c.Params.Get("lang")
	if hasParam && pLang != lang {
		lang = pLang
		session.Set("lang", lang)
		session.Save()
	}

	if lang != "sgs" && lang != "en" {
		lang = "sgs"
		session.Set("lang", lang)
		session.Save()
	}

	return lang
}

func getGameFlow(c *gin.Context) (string, int) {
	gameFlow := c.Param("game")
	if "0" == gameFlow {
		return gameFlow, GameStateWaitingUser
	}

	if "x" == gameFlow {
		return "", GameStateInProgress
	}

	if "0" == string(gameFlow[0]) {
		gameFlow = string(gameFlow[1:])
	}

	if len(gameFlow) >= 9 {
		return gameFlow, GameStateEnded
	}

	return gameFlow, GameStateInProgress
}

func getNewClick(gameFlow string) string {
	return difference("123456789", gameFlow)[0]
}

func difference(a, b string) []string {
	mb := make(map[string]struct{}, len(b))
	for _, x := range str2array(b) {
		mb[x] = struct{}{}
	}
	var diff []string
	for _, x := range str2array(a) {
		if _, found := mb[x]; !found {
			diff = append(diff, x)
		}
	}
	return diff
}

func str2array(str string) []string {
	chars := []rune(str)
	var splited []string
	for i := 0; i < len(chars); i++ {
		splited = append(splited, string(chars[i]))
	}

	return splited
}