package api

import (
	"encoding/json"
	"io"
	"log"
	"net/http"

	authdiscord "example.com/auth/discord"
	configserver "example.com/config/server"
	databasecommands "example.com/database/commands"
	databasemodels "example.com/database/models"

	"github.com/gin-gonic/gin"
	"github.com/xyproto/randomstring"
	"golang.org/x/oauth2"
	"gorm.io/gorm"
)

var GlobalDatabase *gorm.DB
var GlobalConfig configserver.AppConfig
var GlobalOAuth *oauth2.Config

// Private Functions

func getDiscordUser(context *gin.Context, oauthToken *oauth2.Token) authdiscord.DiscordUser {
	response, err := GlobalOAuth.Client(context, oauthToken).Get("https://discord.com/api/users/@me")
	if err != nil || response.StatusCode != 200 {
		responseMessage := ""
		if err != nil {
			responseMessage = err.Error()
		} else {
			responseMessage = response.Status
		}
		log.Println(responseMessage)
		log.Println("Assuming the Discord OAuth Key has expired.")
		context.Redirect(http.StatusUnauthorized, "https://localhost:15995/logout")
	}
	defer response.Body.Close()
	body, err := io.ReadAll(response.Body)
	if err != nil {
		log.Println(err)
	}
	var user authdiscord.DiscordUser
	json.Unmarshal(body, &user)
	return user
}

// Authentication Workflow

func AuthCallback(context *gin.Context) {
	oauthState := randomstring.CookieFriendlyString(32)
	context.Set("state", oauthState)
	var err error
	oauthToken, err := GlobalOAuth.Exchange(context.Request.Context(), context.Query("code"))
	if err != nil {
		context.Redirect(http.StatusInternalServerError, "http://localhost:15995/")
	}
	oauthTokenJSON, _ := json.Marshal(oauthToken)
	context.SetCookie("discord-oauthtoken", string(oauthTokenJSON), 0, "", GlobalConfig.API.Domain, false, false)
	context.Set("discord-oauthtoken", string(oauthTokenJSON))
	CreateOrUpdateUser(context)
	context.Redirect(http.StatusTemporaryRedirect, "http://localhost:15995/dashboard")
}

func AuthLoginRedirect(context *gin.Context) {
	context.Redirect(302, GlobalOAuth.AuthCodeURL(context.GetString("state")))
}

func AuthLogoutRedirect(context *gin.Context) {
	oauthTokenJSON, err := context.Cookie("discord-oauthtoken")
	if err == nil {
		databasecommands.LogoutDatabaseUser(GlobalDatabase, oauthTokenJSON)
		context.SetCookie("discord-oauthtoken", "", -1, "", GlobalConfig.API.Domain, false, true)
	} else {
		log.Println(err)
	}
	context.Redirect(http.StatusTemporaryRedirect, "http://localhost:15995/")
}

// Create & Update Endpoints (post/, put/, patch)

func CreateOrUpdateUser(context *gin.Context) {
	oauthTokenJSON, err := context.Cookie("discord-oauthtoken")
	if err != nil {
		oauthTokenJSON = context.GetString("discord-oauthtoken")
	}
	var oauthToken *oauth2.Token
	err = json.Unmarshal([]byte(oauthTokenJSON), &oauthToken)
	if err != nil {
		log.Println(err)
		context.AbortWithStatus(http.StatusBadRequest)
	}
	currentDiscordUser := getDiscordUser(context, oauthToken)
	updatedDatabaseUser := databasemodels.User{
		DisplayName:      currentDiscordUser.Global_Name,
		Username:         currentDiscordUser.Username,
		Id:               currentDiscordUser.Id,
		Avatar:           currentDiscordUser.Avatar,
		AvatarDecoration: currentDiscordUser.Avatar_Decoration_Data.Asset,
		LoginToken:       string(oauthTokenJSON),
		LoggedIn:         true,
	}
	if databasecommands.GetDatabaseUserExists(GlobalDatabase, currentDiscordUser.Id) {
		dbOAuthToken := databasecommands.GetDatabaseUserToken(GlobalDatabase, currentDiscordUser.Id)
		if dbOAuthToken == "" {
			context.SetCookie("discord-oauthtoken", string(oauthTokenJSON), 0, "", GlobalConfig.API.Domain, false, false)
			err := databasecommands.UpdateDatabaseUser(GlobalDatabase, updatedDatabaseUser)
			if err != nil {
				log.Println(err)
				context.AbortWithStatus(http.StatusInternalServerError)
			}
		} else {
			context.SetCookie("discord-oauthtoken", dbOAuthToken, 0, "", GlobalConfig.API.Domain, false, false)
		}
	} else {
		err := databasecommands.CreateDatabaseUser(GlobalDatabase, updatedDatabaseUser)
		if err != nil {
			log.Println(err)
			context.Copy().AbortWithStatus(http.StatusInternalServerError)
		}
	}
}

func CreateDatabaseGroup(context *gin.Context) {

}

// Read Endpoints (get/)

func GetUserInfo(context *gin.Context) {
	oauthTokenJSON, err := context.Cookie("discord-oauthtoken")
	if err == nil {
		var oauthToken *oauth2.Token
		err := json.Unmarshal([]byte(oauthTokenJSON), &oauthToken)
		if err == nil {
			if oauthToken.Valid() {
				user := getDiscordUser(context, oauthToken)
				if databasecommands.GetDatabaseUserLoggedIn(GlobalDatabase, oauthTokenJSON) {
					context.JSON(http.StatusOK, user)
				} else {
					context.Redirect(http.StatusTemporaryRedirect, "http://localhost:31337/auth/logout")
				}
				return
			} else {
				log.Println(err)
				context.AbortWithStatus(http.StatusBadRequest)
			}
		} else {
			log.Println(err)
			context.AbortWithStatus(http.StatusBadRequest)
		}
	} else {
		log.Println(err)
		context.AbortWithStatus(http.StatusBadRequest)
	}
	context.Redirect(http.StatusTemporaryRedirect, "http://localhost:15995/")
}

func GetIsUserAuthorized(context *gin.Context) {
	oauthTokenJSON, err := context.Cookie("discord-oauthtoken")
	if err == nil {
		var oauthToken *oauth2.Token
		err := json.Unmarshal([]byte(oauthTokenJSON), &oauthToken)
		if err == nil {
			if oauthToken.Valid() {
				if databasecommands.GetDatabaseUserLoggedIn(GlobalDatabase, oauthTokenJSON) {
					context.JSON(http.StatusOK, gin.H{
						"message": true,
					})
				} else {
					context.JSON(http.StatusUnauthorized, gin.H{
						"message": true,
					})
				}
				return
			}
		}
	}
	context.JSON(http.StatusUnauthorized, gin.H{
		"message": false,
	})
}

func GetDatabaseGroup(context *gin.Context) {
	groupName := context.Query("group")
	if groupName != "" {
		group := databasecommands.GetDatabaseGroup(GlobalDatabase, groupName)
		context.JSON(http.StatusOK, group)
	} else {
		context.JSON(http.StatusBadRequest, gin.H{
			"name": "",
		})
	}
}

func GetDatabaseGroups(context *gin.Context) {
	groups := databasecommands.GetDatabaseGroups(GlobalDatabase)
	context.JSON(http.StatusOK, gin.H{
		"groups": groups,
	})
}

// Delete Endpoints (delete/)