package main

import (
	v "bitbucket.org/hackerbots/vector"
	"log"
	"math"
	"math/rand"
)

type Robot struct {
	Id             string      `json:"id"`
	Name           string      `json:"name"`
	Message        string      `json:"-"`
	Stats          Stats       `json:"-"`
	TargetSpeed    float32     `json:"-"`
	Speed          float32     `json:"speed"`
	Health         int         `json:"health"`
	RepairCounter  float32     `json:"repair"`
	ScanCounter    float32     `json:"scan_bonus"`
	ActiveScan     bool        `json:"-"`
	Position       v.Point2d   `json:"position"`
	Heading        v.Vector2d  `json:"heading"`
	DesiredHeading *v.Vector2d `json:"-"`
	MoveTo         *v.Point2d  `json:"-"`
	FireAt         *v.Point2d  `json:"-"`
	Scanners       []Scanner   `json:"scanners"`
	LastFired      int         `json:"-"`
	Collision      bool        `json:"collision"`
	Hit            bool        `json:"hit"`
	Probe          *v.Point2d  `json:"probe"`
	ProbeResult    *v.Point2d  `json:"probe_result"`
}

// This is the subset of data we send to players about robots
// that are not theirs.
type OtherRobot struct {
	Id       string     `json:"id"`
	Name     string     `json:"name"`
	Position v.Point2d  `json:"position"`
	Heading  v.Vector2d `json:"heading"`
	Health   int        `json:"health"`
}

func (r Robot) GetTruncatedDetails() OtherRobot {
	return OtherRobot{
		Id:       r.Id,
		Name:     r.Name,
		Position: r.Position,
		Heading:  r.Heading,
		Health:   r.Health,
	}
}

type RobotSorter struct {
	Robots []OtherRobot
}

func (s RobotSorter) Len() int {
	return len(s.Robots)
}

func (s RobotSorter) Swap(i, j int) {
	s.Robots[i], s.Robots[j] = s.Robots[j], s.Robots[i]
}

func (s RobotSorter) Less(i, j int) bool {
	return s.Robots[i].Id < s.Robots[j].Id
}

// TODO - how do I not duplicate this code???
type AllRobotSorter struct {
	Robots []BotHealth
}

func (s AllRobotSorter) Len() int {
	return len(s.Robots)
}

func (s AllRobotSorter) Swap(i, j int) {
	s.Robots[i], s.Robots[j] = s.Robots[j], s.Robots[i]
}

func (s AllRobotSorter) Less(i, j int) bool {
	return s.Robots[i].RobotId < s.Robots[j].RobotId
}

type Stats struct {
	Hp            int     `json:"-"`
	Speed         float32 `json:"-"`
	Acceleration  float32 `json:"-"`
	WeaponRadius  int     `json:"-"`
	ScannerRadius int     `json:"-"`
	TurnSpeed     int     `json:"-"`
	FireRate      int     `json:"-"`
	WeaponDamage  int     `json:"-"`
	WeaponSpeed   float32 `json:"-"`
}

// We request stats using an integer between 1 and 100, the
// integer values map to sensible min-max ranges
type StatsRequest struct {
	Hp            int `json:"hp"`
	Speed         int `json:"speed"`
	Acceleration  int `json:"acceleration"`
	WeaponRadius  int `json:"weapon_radius"`
	ScannerRadius int `json:"scanner_radius"`
	TurnSpeed     int `json:"turn_speed"`
	FireRate      int `json:"fire_rate"`
	WeaponDamage  int `json:"weapon_damage"`
	WeaponSpeed   int `json:"weapon_speed"`
}

func DeriveStats(request StatsRequest) Stats {
	s := Stats{}

	// Conversion Tables
	var hp_min float32 = 20.0
	var hp_max float32 = 200.0
	s.Hp = int(((float32(request.Hp) / 100.0) * (hp_max - hp_min)) + hp_min)

	var speed_min float32 = 40.0
	var speed_max float32 = 200.0
	s.Speed = ((float32(request.Speed) / 100.0) * (speed_max - speed_min)) + speed_min

	var accel_min float32 = 20.0
	var accel_max float32 = 200.0
	s.Acceleration = ((float32(request.Acceleration) / 100.0) * (accel_max - accel_min)) + accel_min

	var wep_rad_min float32 = 5.0
	var wep_rad_max float32 = 60.0
	s.WeaponRadius = int(((float32(request.WeaponRadius) / 100.0) * (wep_rad_max - wep_rad_min)) + wep_rad_min)

	var scan_rad_min float32 = 100.0
	var scan_rad_max float32 = 400.0
	s.ScannerRadius = int(((float32(request.ScannerRadius) / 100.0) * (scan_rad_max - scan_rad_min)) + scan_rad_min)

	var turn_spd_min float32 = 30.0
	var turn_spd_max float32 = 300.0
	s.TurnSpeed = int(((float32(request.TurnSpeed) / 100.0) * (turn_spd_max - turn_spd_min)) + turn_spd_min)

	var fire_rate_min float32 = 10.0
	var fire_rate_max float32 = 2000.0
	s.FireRate = int(fire_rate_max+300.0) - int(((float32(request.FireRate)/100.0)*(fire_rate_max-fire_rate_min))+fire_rate_min)

	var weapon_damage_min float32 = 0.0
	var weapon_damage_max float32 = 20.0
	s.WeaponDamage = int(((float32(request.WeaponDamage) / 100.0) * (weapon_damage_max - weapon_damage_min)) + weapon_damage_min)

	var weapon_speed_min float32 = 80.0
	var weapon_speed_max float32 = 600.0
	s.WeaponSpeed = float32(((float32(request.WeaponSpeed) / 100.0) * (weapon_speed_max - weapon_speed_min)) + weapon_speed_min)

	return s
}

type Instruction struct {
	Message     *string     `json:"message,omitempty"`
	MoveTo      *v.Point2d  `json:"move_to,omitempty"`
	Heading     *v.Vector2d `json:"heading,omitempty"`
	FireAt      *v.Point2d  `json:"fire_at,omitempty"`
	Probe       *v.Point2d  `json:"probe,omitempty"`
	TargetSpeed *float32    `json:"target_speed,omitempty"`
	Repair      *bool       `json:"repair,omitempty"`
	Scan        *bool       `json:"scan,omitempty"`
}

func (r *Robot) checkCollisions(g *game, move_vector v.Vector2d) (bool, v.Point2d, *Robot) {
	collision := false
	intersection_point := v.Point2d{X: 0, Y: 0}

	// Check Walls
	r_walls := v.Rect2d{A: v.Point2d{X: 0, Y: 0}, B: v.Point2d{X: g.width, Y: g.height}}
	collision, _, pos := v.RectIntersection(r_walls, r.Position, move_vector)
	if collision {
		return collision, pos, nil
	}

	// Check Other Bots
	for player := range g.players {
		for _, bot := range player.Robots {
			if bot.Id == r.Id {
				continue
			}
			player_rect := v.RectFromPoint(bot.Position, 3)
			collision, _, pos := v.RectIntersection(player_rect, r.Position, move_vector)
			if collision {
				return collision, pos, bot
			}
		}
	}

	// Check Obstacles
	for _, obj := range g.obstacles {
		collision, _, pos := v.RectIntersection(obj.Bounds, r.Position, move_vector)
		if collision {
			return collision, pos, nil
		}
	}

	return collision, intersection_point, nil
}

func (r *Robot) Tick(g *game) {
	r.Collision = false
	r.Hit = false
	r.scan(g)

	// Adjust Speed
	if r.Speed < r.TargetSpeed {
		r.Speed += (r.Stats.Acceleration * delta)
		if r.Speed > r.TargetSpeed {
			r.Speed = r.TargetSpeed
		}

	} else if float32(math.Abs(float64(r.Speed-r.TargetSpeed))) > v.Epsilon {
		r.Speed -= (r.Stats.Acceleration * delta)
	} else {
		r.Speed = r.TargetSpeed
	}

	// Adjust Heading
	current_heading := r.Heading
	if current_heading.Mag() == 0 && r.MoveTo != nil {
		// We may have been stopped before this and had no heading
		current_heading = r.MoveTo.Sub(r.Position).Normalize()
	}

	new_heading := current_heading
	if r.MoveTo != nil {
		// Where do we WANT to be heading?
		new_heading = r.MoveTo.Sub(r.Position).Normalize()
	}

	if r.DesiredHeading != nil {
		// Where do we WANT to be heading?
		new_heading = r.DesiredHeading.Normalize()
	}

	if new_heading.Mag() > 0 {
		// Is our direction change too much? Hard coding to 5 degrees/s for now
		angle := v.Angle(current_heading, new_heading) * v.Rad2deg

		dir := 1.0
		if angle < 0 {
			dir = -1.0
		}

		// Max turn radius in this case is in degrees per second
		if float32(math.Abs(float64(angle))) > (float32(r.Stats.TurnSpeed) * delta) {
			// New heading should be a little less, take current heading and
			// rotate by the max turn radius per frame.
			rot := (float32(r.Stats.TurnSpeed) * delta) * v.Deg2rad

			new_heading = current_heading.Rotate(rot * float32(dir))
		}

		move_vector := new_heading.Scale(r.Speed * delta)
		collision, intersection_point, hit_robot := r.checkCollisions(g, move_vector)
		if collision {
			r.Collision = true
			if hit_robot != nil {
				hit_robot.Health -= int(r.Speed / 10.0)
				hit_robot.Speed = (hit_robot.Speed * 0.1)
				hit_robot.Heading = r.Heading
			}
			move_by := intersection_point.Sub(r.Position)
			move_dist := move_by.Scale(float32(math.Floor(float64(move_by.Mag()-3.0))) / move_by.Mag())

			r.Position = r.Position.Add(move_dist)
			r.Health -= int(r.Speed / 10.0)
			r.MoveTo = &r.Position
			r.Speed = (r.Speed * 0.1)
			r.Heading = r.Heading.Scale(-1.0)
		} else {
			r.Position = r.Position.Add(move_vector)
			if new_heading.Mag() > 0 {
				r.Heading = new_heading
			} else {
				log.Printf("Zero Heading %v", new_heading)
			}
		}
	}

	// We only self repair when we're stopped
	if math.Abs(float64(r.Speed)) < v.Epsilon && r.RepairCounter > 0 {
		r.RepairCounter -= delta
		if r.RepairCounter < 0 {
			r.Health += g.repair_hp
			if r.Health > r.Stats.Hp {
				r.Health = r.Stats.Hp
			}
			r.RepairCounter = g.repair_rate
		}
	}

	// We are only allowed to scan when we're stopped
	if math.Abs(float64(r.Speed)) < v.Epsilon && r.ActiveScan {
		r.ScanCounter += delta * float32(r.Stats.ScannerRadius) * 0.1
	} else if r.ScanCounter > 0 {
		r.ScanCounter -= delta * float32(r.Stats.ScannerRadius) * 0.05
		if r.ScanCounter <= 0 {
			r.ScanCounter = 0
		}
	}

	if r.FireAt != nil {
		proj := r.fire(g.projectiles, g.turn)
		if proj != nil {
			g.projectiles[proj] = true
		}
	}

	if r.Probe != nil && r.ProbeResult == nil {
		probe_vector := r.Probe.Sub(r.Position)
		coll, pos, _ := r.checkCollisions(g, probe_vector)
		if coll {
			r.ProbeResult = &pos
		}
	}
}

func (r *Robot) scan(g *game) {
	r.Scanners = r.Scanners[:0]
	for player := range g.players {
		for _, bot := range player.Robots {
			if bot.Id == r.Id || bot.Health <= 0 {
				continue
			}
			dist := v.Distance(bot.Position, r.Position)
			if dist < float32(r.Stats.ScannerRadius+int(r.ScanCounter)) {
				s := Scanner{
					Id:   bot.Id,
					Type: "robot",
				}
				r.Scanners = append(r.Scanners, s)
			}
		}
	}

	for proj := range g.projectiles {
		if proj.Owner == r {
			continue
		}

		dist := v.Distance(proj.Position, r.Position)
		if dist < float32(r.Stats.ScannerRadius+int(r.ScanCounter)) {
			s := Scanner{
				Id:   proj.Id,
				Type: "projectile",
			}
			r.Scanners = append(r.Scanners, s)
		}
	}

}

func (r *Robot) fire(projectiles map[*Projectile]bool, turn int) *Projectile {
	// Throttle the fire rate
	time_since_fired := (float32(turn) * (delta * 1000)) - (float32(r.LastFired) * (delta * 1000))
	if time_since_fired < float32(r.Stats.FireRate) {
		return nil
	}

	r.LastFired = turn

	return &Projectile{
		Id:       idg.Hash(),
		Position: r.Position,
		MoveTo:   *r.FireAt,
		Damage:   r.Stats.WeaponDamage,
		Radius:   r.Stats.WeaponRadius,
		Speed:    r.Stats.WeaponSpeed,
		Owner:    r,
	}
}

func (r *Robot) reset(g *game) {
	for {
		start_pos := v.Point2d{
			X: rand.Float32() * float32(g.width),
			Y: rand.Float32() * float32(g.height),
		}
		r.MoveTo = &start_pos
		r.Position = start_pos
		r.Health = r.Stats.Hp

		// Check Obstacles
		retry := false
		for _, obj := range g.obstacles {
			_, inside, _ := v.RectIntersection(obj.Bounds, r.Position, v.Vector2d{0, 0})
			if inside {
				retry = true
			}
		}
		if !retry {
			break
		}
	}
}