package routes

import (
	"crypto/sha512"
	"encoding/hex"
	"net/http"

	"git.1750studios.com/ToddShepard/ShortDragon/database"
	"github.com/gin-gonic/gin"
	"github.com/jinzhu/gorm"
	"github.com/spf13/viper"
)

// Redirect redirects a user to the long URL specified by the short URL
func Redirect(c *gin.Context) {
	var URL database.URL
	short := c.Param("short")
	err := database.Db.First(&URL, "short = ?", short).Error
	if err != nil {
		c.Redirect(http.StatusFound, viper.GetString("DefaultURL"))
		return
	}
	if !URL.Long.Valid {
		c.Redirect(http.StatusFound, viper.GetString("DefaultURL"))
		return
	}
	if URL.Hits.Valid && !(c.Request.Header.Get("DNT") == "1") {
		URL.Hits.Int64 = URL.Hits.Int64 + 1
		database.Db.Save(&URL)
	}
	c.Redirect(http.StatusFound, URL.Long.String)
	return
}

// Encode encodes a long URL and returns the short one
func Encode(c *gin.Context) {
	var URL database.URL
	var count uint
	URL.Long.String = c.PostForm("LongURL")
	URL.Long.Valid = true
	database.Db.Where("long = ?", URL.Long.String).FirstOrInit(&URL)
	if URL.Short.Valid {
		c.Data(http.StatusOK, "text/plain", []byte(viper.GetString("ShortURL")+"/"+URL.Short.String))
		return
	}
	URL.Short.String = c.DefaultPostForm("ShortURL", "")
	if URL.Short.String == "" {
		hasher := sha512.New()
		hasher.Write([]byte(URL.Long.String))
		hash := hex.EncodeToString(hasher.Sum(nil))
		i := 2
		for {
			database.Db.Model(&database.URL{}).Where("short = ?", hash[0:i]).Count(&count)
			if count > 0 && i < len(hash) {
				i = i + 1
			} else if count > 0 {
				c.AbortWithStatus(http.StatusConflict)
				return
			} else {
				URL.Short.String = hash[0:i]
				break
			}
		}
	}
	URL.Short.Valid = true
	URL.Hits.Int64 = 0
	if c.DefaultPostForm("track", "true") == "true" {
		URL.Hits.Valid = true
	} else {
		URL.Hits.Valid = false
	}
	err := database.Db.Create(&URL).Error
	if err != nil {
		c.AbortWithError(http.StatusBadRequest, err)
		return
	}
	c.Data(http.StatusCreated, "text/plain", []byte(viper.GetString("ShortURL")+"/"+URL.Short.String))
	return
}

// Decode decodes a short URL and returns the long one
func Decode(c *gin.Context) {
	var URL database.URL
	short := c.Param("short")
	err := database.Db.Where("short = ?", short).Find(&URL).Error
	if err != nil && err == gorm.ErrRecordNotFound {
		c.Data(http.StatusNotFound, "text/plain", []byte("Record not found"))
		return
	} else if err != nil {
		c.AbortWithError(http.StatusInternalServerError, err)
		return
	}
	c.Data(http.StatusOK, "text/plain", []byte(URL.Long.String))
}

// Info decodes a short URL and returns the database content
func Info(c *gin.Context) {
	var URL database.URL
	short := c.Param("short")
	err := database.Db.Where("short = ?", short).Find(&URL).Error
	if err != nil && err == gorm.ErrRecordNotFound {
		c.Data(http.StatusNotFound, "text/plain", []byte("Record not found"))
		return
	} else if err != nil {
		c.AbortWithError(http.StatusInternalServerError, err)
		return
	}
	c.JSON(http.StatusOK, URL)
}