package main

import (
	"bitbucket.org/hackerbots/vector"
	"code.google.com/p/go.net/websocket"
	"encoding/json"
	"errors"
	"flag"
	"fmt"
	"log"
	"math/rand"
	"net/http"
	"time"
)

var hp = flag.Int("hp", 150, "")
var speed = flag.Float64("speed", 150, "")
var acceleration = flag.Float64("acceleration", 10, "")
var weaponRadius = flag.Int("wrad", 100, "weapon radius")
var scannerRadius = flag.Int("srad", 100, "scanner radius")
var server = flag.String("server", "localhost", "server hostname")
var port = flag.Int("port", 8666, "server port")
var botname = flag.String("name", "gobot", "the name that other players will see")
var verbose = flag.Bool("verbose", false, "run verbosly")

type infos struct {
	id            string
	width, height float64
}

type Stats struct {
	Hp            int     `json:"hp"`
	Speed         float64 `json:"speed"`
	Acceleration  float64 `json:"acceleration"`
	WeaponRadius  int     `json:"weapon_radius"`
	ScannerRadius int     `json:"scanner_radius"`
}

type Scanner struct {
	Position govector.Point2d `json:"position"`
	Stats    Stats            `json:"stats"`
}

type Robot struct {
	Id          string            `json:"id"`
	Name        string            `json:"name"`
	Stats       Stats             `json:"stats"`
	TargetSpeed float64           `json:"speed"`
	Speed       float64           `json:"speed"`
	Health      int               `json:"health"`
	Position    govector.Point2d  `json:"position"`
	Heading     govector.Vector2d `json:"heading"`
	MoveTo      *govector.Point2d `json:"move_to,omitempty"`
	FireAt      *govector.Point2d `json:"fire_at,omitempty"`
	Scanners    []Scanner         `json:"scanners"`
}

type Projectile struct {
	Id       string           `json:"id"`
	Position govector.Point2d `json:"position"`
	MoveTo   govector.Point2d `json:"move_to"`
	Radius   int              `json:"radius"`
	Speed    float64          `json:"speed"`
	Damage   int              `json:"damage"`
}

type Splosion struct {
	Id        string           `json:"id"`
	Position  govector.Point2d `json:"position"`
	Radius    int              `json:"radius"`
	MaxDamage int              `json:"damage"`
	MinDamage int              `json:"damage"`
	Lifespan  int              `json:"lifespan"`
}

type Instruction struct {
	MoveTo *govector.Point2d `json:"move_to,omitempty"`
	FireAt *govector.Point2d `json:"fire_at,omitempty"`
	Stats  Stats             `json:"stats"`
}

func connect() (*websocket.Conn, error) {
	origin := "http://localhost/"
	url := fmt.Sprintf("ws://%s:%d/ws/", *server, *port)
	return websocket.Dial(url, "", origin)
}

func createGame() (string, error) {
	url := fmt.Sprintf("http://%s:%d/game/start/", *server, *port)
	resp, err := http.Get(url)
	if err != nil {
		return "", err
	}
	defer resp.Body.Close()

	var g struct {
		Id string `json:"id"`
	}
	if err := json.NewDecoder(resp.Body).Decode(&g); err != nil {
		return "", err
	}
	return g.Id, err
}

func negociate(ws *websocket.Conn, gameid string) (i *infos, err error) {
	log.Printf("trying to connect to game %s", gameid)
	err = websocket.JSON.Send(ws, struct {
		Id string `json:"id"`
	}{
		gameid,
	})
	if err != nil {
		return nil, err
	}

	var idreq struct {
		Type       string `json:"type"`
		AssignedID string `json:"id"`
	}
	err = websocket.JSON.Receive(ws, &idreq)
	if err != nil || idreq.Type == "failure" {
		return nil, errors.New(fmt.Sprintf("failure: %+v", idreq))
	}
	log.Printf("%+v", idreq)

	err = websocket.JSON.Send(ws, struct {
		Type      string `json:"type"`
		Name      string `json:"name"`
		Useragent string `json:"useragent"`
	}{
		Name:      *botname,
		Useragent: "gobot",
		Type:      "robot",
	})
	if err != nil {
		return nil, err
	}

	type BoardSize struct {
		Width  float64 `json:"width"`
		Height float64 `json:"height"`
	}
	var gameparam struct {
		BoardSize BoardSize `json:"boardsize"`

		Type string `json:"type"`
	}
	err = websocket.JSON.Receive(ws, &gameparam)
	log.Printf("gameparam: %+v", gameparam)
	if gameparam.Type != "gameparam" {
		return nil, errors.New("didn't receive a good gameparam")
	}
	log.Printf("%+v", gameparam)

	err = websocket.JSON.Send(ws, &struct {
		ID   string `json:"id"`
		Name string `json:"name"`
		// TODO: candidate for embedding?
		Stats Stats `json:"stats"`
	}{
		ID:   gameid,
		Name: *botname,
		Stats: Stats{
			Hp:            *hp,
			Speed:         *speed,
			Acceleration:  *acceleration,
			WeaponRadius:  *weaponRadius,
			ScannerRadius: *scannerRadius,
		},
	})

	var handshake struct {
		ID      string `json:"id"`
		Success bool   `json:"success"`
		Type    string `json:"type"`
	}
	websocket.JSON.Receive(ws, &handshake)
	if !handshake.Success {
		return nil, errors.New("failed to validate correct stats request")
	}
	log.Printf("%+v", handshake)
	return &infos{
		id:     idreq.AssignedID,
		width:  gameparam.BoardSize.Width,
		height: gameparam.BoardSize.Height,
	}, err
}

func main() {
	rand.Seed(time.Now().UnixNano())
	var err error
	var gameid string
	flag.Parse()
	if flag.NArg() < 1 {
		gameid, err = createGame()
		if err != nil {
			log.Fatal(err)
		}
	} else {
		gameid = flag.Arg(0)
	}

	ws, err := connect()
	if err != nil {
		log.Fatal(err)
	}
	board_info, err := negociate(ws, gameid)
	if err != nil {
		log.Fatal(err)
	}

	// TODO: var target govector.Point2d
	moveto := govector.Point2d{
		X: rand.Float64() * board_info.width,
		Y: rand.Float64() * board_info.height,
	}
	log.Printf("%+v", moveto)

	var me Robot

	log.Printf("negociated well, starting loop")
	for {
		var boardstate struct {
			Robots      []Robot      `json:"robots"`
			Projectiles []Projectile `json:"projectiles"`
			Splosions   []Splosion   `json:"splosions"`
			Reset       bool         `json:"reset"`
			Type        string       `json:"type"`
			Turn        int          `json:"turn"`
		}
		err = websocket.JSON.Receive(ws, &boardstate)
		if *verbose {
			log.Printf("%+v", boardstate)
		}
		if err != nil {
			log.Fatal("Connection lost")
		}
		for _, bot := range boardstate.Robots {
			if bot.Id == board_info.id {
				me = bot
				break
			}
		}
		if govector.Distance(me.Position, moveto) < 3.0 {
			log.Printf("old: %+v: %+v", me.Position, moveto)
			moveto = govector.Point2d{
				X: rand.Float64() * board_info.width,
				Y: rand.Float64() * board_info.height,
			}
			log.Printf("new: %+v: %+v", me.Position, moveto)
		}

		// TODO: send instructions
		err = websocket.JSON.Send(ws, Instruction{
			MoveTo: &moveto,
		})
		if err != nil {
			log.Fatal(err)
		}
	}
}