/******************************************************************************
 * Discordgo by Bruce Marriner <bruce@sqls.net>
 * A Discord API for Golang.
 * See discord.go for more information.
 *
 * This file contains functions for interacting with the Discord API
 * at the lowest level.  See other files for easier methods of access.
 */

package discordgo

import (
	"bytes"
	"encoding/json"
	"errors"
	"fmt"
	"io/ioutil"
	"net/http"
	"time"
)

// Request makes a REST API GET Request with Discord.
// TODO make this handle GET, POST, DELETE, etc
func Request(session *Session, urlStr string) (body []byte, err error) {

	req, err := http.NewRequest("GET", urlStr, bytes.NewBuffer([]byte(fmt.Sprintf(``))))
	if err != nil {
		return
	}

	req.Header.Set("authorization", session.Token)
	req.Header.Set("Content-Type", "application/json")
	client := &http.Client{Timeout: (20 * time.Second)}
	resp, err := client.Do(req)
	if err != nil {
		return
	}

	body, err = ioutil.ReadAll(resp.Body)
	resp.Body.Close()
	if err != nil {
		return
	}

	if resp.StatusCode != 200 {
		err = errors.New(fmt.Sprintf("StatusCode: %d, %s", resp.StatusCode, string(body)))
		return
	}

	if session.Debug {
		var prettyJSON bytes.Buffer
		error := json.Indent(&prettyJSON, body, "", "\t")
		if error != nil {
			fmt.Print("JSON parse error: ", error)
			return
		}
		fmt.Println(urlStr+" Response:\n", string(prettyJSON.Bytes()))
	}
	return
}

// Login asks the Discord server for an authentication token
func Login(session *Session, email string, password string) (token string, err error) {

	var urlStr string = fmt.Sprintf("%s/%s", discordApi, "auth/login")
	req, err := http.NewRequest("POST", urlStr, bytes.NewBuffer([]byte(fmt.Sprintf(`{"email":"%s", "password":"%s"}`, email, password))))
	if err != nil {
		return
	}
	req.Header.Set("Content-Type", "application/json")

	client := &http.Client{Timeout: (20 * time.Second)}
	resp, err := client.Do(req)
	if err != nil {
		return
	}
	defer resp.Body.Close()

	body, _ := ioutil.ReadAll(resp.Body)
	if resp.StatusCode != 200 {
		err = errors.New(fmt.Sprintf("StatusCode: %d, %s", resp.StatusCode, string(body)))
		return
	}

	if session.Debug {
		var prettyJSON bytes.Buffer
		error := json.Indent(&prettyJSON, body, "", "\t")
		if error != nil {
			fmt.Print("JSON parse error: ", error)
			return
		}
		fmt.Println("requestToken Response:\n", string(prettyJSON.Bytes()))
	}

	temp := &Session{} // TODO Must be a better way
	err = json.Unmarshal(body, &temp)
	token = temp.Token
	return
}

// Returns the user details of the given userId
// session : An active session connection to Discord
// user    : A user Id or name
func Users(session *Session, userId string) (user User, err error) {

	body, err := Request(session, fmt.Sprintf("%s/users/%s", discordApi, userId))
	err = json.Unmarshal(body, &user)
	return
}

// PrivateChannels returns an array of Channel structures for all private
// channels for a user
func PrivateChannels(session *Session, userId string) (channels []Channel, err error) {

	body, err := Request(session, fmt.Sprintf("%s/%s", discordApi, fmt.Sprintf("users/%s/channels", userId)))
	err = json.Unmarshal(body, &channels)

	return
}

// Servers returns an array of Server structures for all servers for a user
func Servers(session *Session, userId string) (servers []Server, err error) {

	body, err := Request(session, fmt.Sprintf("%s/users/%s/guilds", discordApi, userId))
	err = json.Unmarshal(body, &servers)

	return
}

// Members returns an array of Member structures for all members of a given
// server.
func Members(session *Session, serverId int) (members []Member, err error) {

	body, err := Request(session, fmt.Sprintf("%s/guilds/%d/members", discordApi, serverId))
	err = json.Unmarshal(body, &members)

	return
}

// Channels returns an array of Channel structures for all channels of a given
// server.
func Channels(session *Session, serverId int) (channels []Channel, err error) {

	body, err := Request(session, fmt.Sprintf("%s/guilds/%d/channels", discordApi, serverId))
	err = json.Unmarshal(body, &channels)

	return
}

// Messages returns an array of Message structures for messaages within a given
// channel.  limit, beforeId, and afterId can be used to control what messages
// are returned.
func Messages(session *Session, channelId int, limit int, afterId int, beforeId int) (messages []Message, err error) {

	var urlStr string

	if limit > 0 {
		urlStr = fmt.Sprintf("%s/channels/%d/messages?limit=%d", discordApi, channelId, limit)
	}

	if afterId > 0 {
		if urlStr != "" {
			urlStr = urlStr + fmt.Sprintf("&after=%d", afterId)
		} else {
			urlStr = fmt.Sprintf("%s/channels/%d/messages?after=%d", discordApi, channelId, afterId)
		}
	}

	if beforeId > 0 {
		if urlStr != "" {
			urlStr = urlStr + fmt.Sprintf("&before=%d", beforeId)
		} else {
			urlStr = fmt.Sprintf("%s/channels/%d/messages?after=%d", discordApi, channelId, beforeId)
		}
	}

	if urlStr == "" {
		urlStr = fmt.Sprintf("%s/channels/%d/messages", discordApi, channelId)
	}

	fmt.Println(urlStr)
	body, err := Request(session, urlStr)
	err = json.Unmarshal(body, &messages)

	return
}

// SendMessage sends a message to the given channel.
func SendMessage(session *Session, channelId int, message string) (response Message, err error) {

	var urlStr string = fmt.Sprintf("%s/channels/%d/messages", discordApi, channelId)

	req, err := http.NewRequest("POST", urlStr, bytes.NewBuffer([]byte(fmt.Sprintf(`{"content":"%s"}`, message))))
	if err != nil {
		return
	}

	req.Header.Set("authorization", session.Token)
	req.Header.Set("Content-Type", "application/json")

	client := &http.Client{Timeout: (20 * time.Second)}
	resp, err := client.Do(req)
	if err != nil {
		return
	}

	body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return
	}
	resp.Body.Close()

	if resp.StatusCode != 200 {
		err = errors.New(fmt.Sprintf("StatusCode: %d, %s", resp.StatusCode, string(body)))
		return
	}

	if session.Debug {
		var prettyJSON bytes.Buffer
		error := json.Indent(&prettyJSON, body, "", "\t")
		if error != nil {
			fmt.Print("JSON parse error: ", error)
			return
		}
		fmt.Println(urlStr+" Response:\n", string(prettyJSON.Bytes()))
	}

	err = json.Unmarshal(body, &response)
	return
}

// Close ends a session and logs out from the Discord REST API.
func Logout(session *Session) (err error) {
	req, err := http.NewRequest("POST", fmt.Sprintf("%s/%s", discordApi, fmt.Sprintf("auth/logout")), bytes.NewBuffer([]byte(fmt.Sprintf(``))))
	if err != nil {
		return
	}
	req.Header.Set("authorization", session.Token)
	req.Header.Set("Content-Type", "application/json")
	client := &http.Client{Timeout: (20 * time.Second)}
	resp, err := client.Do(req)
	if err != nil {
		return
	}

	body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return
	}
	resp.Body.Close()

	if resp.StatusCode != 204 && resp.StatusCode != 200 {
		err = errors.New(fmt.Sprintf("StatusCode: %d, %s", resp.StatusCode, string(body)))
		return
	}
	return
}