package game

import (
	"log"
)

const (
	DEFAULT_AVAIL_STREET_ACTIONS = 1
	DEFAULT_AVAIL_MOVE_ACTIONS   = 1
	DEFAULT_AVAIL_ATTACK_ACTIONS = 1
)

type Unit struct {
	permanentBase
	Health      int
	Movement    Movement
	Attack      Attack
	upkeep      *ResourceCosts
	FullActions []*FullAction
	FreeActions []*FreeAction
	// Effects []Effects
	AvailStreetActions      int
	AvailMoveActions        int
	additionalMoveActions   int
	AvailAttackActions      int
	additionalAttackActions int
}

func NewUnit(card *Card, tile *Tile, owner *Player) *Unit {
	if !card.Type.IsUnit() {
		log.Panic(card.Name, " is not a unit")
	}
	var movement Movement
	movementDesc, found := card.Values["movement"]
	if !found {
		movement = INVALID_MOVEMENT()
	} else {
		movement = parseMovement(movementDesc)
	}

	upkeep := card.PlayCosts
	if upkeep == nil {
		upkeep = &ResourceCosts{fixed: 0}
	}

	var attack Attack
	if attackDesc, found := card.Values["attack"]; found {
		attack = parseAttack(attackDesc)
	}

	u := &Unit{
		permanentBase:      newPermanentBase(card, tile, owner),
		Health:             int(card.Values["health"].(uint64)),
		Movement:           movement,
		Attack:             attack,
		upkeep:             upkeep,
		AvailMoveActions:   DEFAULT_AVAIL_MOVE_ACTIONS,
		AvailStreetActions: DEFAULT_AVAIL_STREET_ACTIONS,
		AvailAttackActions: DEFAULT_AVAIL_ATTACK_ACTIONS,
	}

	// TODO: parse effect for additional actions

	u.FullActions = card.Impl.fullActions(u)
	u.FreeActions = card.Impl.freeActions(u)

	return u
}

func (u *Unit) String() string {
	return FmtPermanent(u)
}

func NewUnitFromPath(cardPath string, tile *Tile, owner *Player) *Unit {
	return NewUnit(NewCard(cardPath), tile, owner)
}

func (u *Unit) UpkeepCost() int {
	return u.upkeep.Costs(u.controller.gameState)
}

func (u *Unit) resetBaseActions() {
	u.AvailStreetActions = DEFAULT_AVAIL_STREET_ACTIONS + u.additionalMoveActions
	u.AvailMoveActions = DEFAULT_AVAIL_MOVE_ACTIONS + u.additionalMoveActions
	u.AvailAttackActions = DEFAULT_AVAIL_ATTACK_ACTIONS + u.additionalAttackActions
}

func (u *Unit) onUpkeep() {
	u.resetBaseActions()
	getCardImplementation(u.Card()).onUpkeep(u)

	if u.Marks(UnitStates.Poison) > 0 {
		u.adjustMarks(UnitStates.Poison, 1)
	}

	if u.Marks(UnitStates.Paralysis) > 0 {
		u.adjustMarks(UnitStates.Paralysis, -1)
		u.tap()
	}
}

func (u *Unit) MoveRangeTiles() []*Tile {
	tiles := []*Tile{}
	m := u.controller.gameState.Map()
	graph := m.generateMovementRangeGraphFor(u)
	origin := TileOrContainingPermTile(u).Position
	for _, pos := range PositionsInRange(origin, u.Movement.Range, false) {
		tile := m.TileAt(pos)
		if tile == nil || !u.IsAvailableTile(tile) {
			continue
		}

		path, err := findPathTo(graph, u, pos)
		if err != nil {
			continue
		}

		if path.Distance/2 > int64(u.Movement.Range) {
			continue
		}

		tiles = append(tiles, tile)
	}
	return tiles
}

func (u *Unit) AttackableTile(t *Tile) (bool, Attack) {
	if flexAttack := u.Attack.flexAttack; flexAttack != nil {
		if _, ok := flexAttack(u, t); ok {
			return true, u.Attack
		}
	}

	return IsPositionInRange(u.Tile().Position, t.Position, u.Attack.MaxRange()), u.Attack
}

func (u *Unit) AttackableTiles() []*Tile {
	// Units not on the map can not attack
	if u.tile == nil {
		return nil
	}

	m := u.controller.gameState.Map()
	var tilesInRange []*Tile
	if flexAttack := u.Attack.flexAttack; flexAttack != nil {
		tilesInRange = m.FilterTiles(func(t *Tile) bool { _, ok := flexAttack(u, t); return ok })
	} else {
		tilesInRange = TilesInRange(m, u, u.Attack.MaxRange())
		if u.Attack.MaxRange() == 1 {
			return tilesInRange
		}
	}

	// House tiles are not attackable from ranges > 1
	aTiles := []*Tile{}
	for _, t := range tilesInRange {
		if DistanceBetweenPositions(t.Position, u.tile.Position) > 1 && t.Type == TileTypes.House {
			continue
		}
		aTiles = append(aTiles, t)
	}
	return aTiles
}

func (u *Unit) AttackablePermanents() []Permanent {
	permanents := []Permanent{}
	for _, t := range u.AttackableTiles() {
		if t.Permanent != nil && t.Permanent.Attackable() {
			permanents = append(permanents, t.Permanent)
		}
	}
	return permanents
}

func (u *Unit) AttackableEnemyPermanents() []Permanent {
	controller := u.Controller()
	permanents := []Permanent{}
	for _, t := range u.AttackableTiles() {
		if t.Permanent != nil && t.Permanent.Attackable() &&
			t.Permanent.Controller() != controller {

			permanents = append(permanents, t.Permanent)
		}
	}
	return permanents
}

func (u *Unit) fight(p Permanent) {
	d, reachable := u.Attack.DamageForTile(u, p.Tile())
	if reachable {
		DealDamage(u, p, d)
	}
}

func (u *Unit) IsDestroyed() bool {
	return u.damage >= u.Health || u.Marks(UnitStates.Poison) >= u.Health*2
}

func (u *Unit) HasFullAction() bool {
	return len(u.FullActions) > 0
}

func (u *Unit) tap() {
	u.AvailMoveActions = 0
	u.AvailAttackActions = 0
}

func (u *Unit) AvailSlowActions() (actions []Action) {
	// TODO: implement panic and rage marks
	if u.Marks(UnitStates.Panic) > 0 {
	}
	if u.Marks(UnitStates.Rage) > 0 {
	}

	if u.AvailMoveActions > 0 && u.Movement != INVALID_MOVEMENT() {
		actions = append(actions, NewMoveAction(u))
	}

	if u.AvailStreetActions > 0 && u.Movement != INVALID_MOVEMENT() && u.Tile() != nil && u.Tile().Type == TileTypes.Street {
		actions = append(actions, NewStreetAction(u))
	}

	m := u.Controller().gameState.Map()
	if u.AvailAttackActions > 0 && u.Attack.Valid() &&
		len(u.AttackableEnemyPermanents()) > 0 {

		actions = append(actions, NewAttackAction(u))
	}

	if u.AvailAttackActions > 0 && u.AvailMoveActions > 0 {
		for _, p := range u.FullActions {
			actions = append(actions, p)
		}
	}

	if u.AvailAttackActions > 0 || u.AvailMoveActions > 0 {
		for _, t := range TilesInRange(m, u, 1) {
			if t.Permanent == nil {
				continue
			}

			// Equipment Actions
			if equipment, ok := t.Permanent.(*Equipment); ok {
				actions = append(actions, NewEquipAction(u, equipment))
			}

			for _, perm := range t.Permanent.Pile() {
				if equipment, ok := perm.(*Equipment); ok {
					actions = append(actions, NewEquipAction(u, equipment))
				}
			}

			// Artifact Actions
			if t.Permanent.Card().Type.IsArtifact() {
				// ArtifactMoveActions are FullActions
				if u.AvailAttackActions > 0 && u.AvailMoveActions > 0 {
					actions = append(actions, newArtifactMoveAction(u, t.Permanent))
				}

				// ArtifactSwitchActions replace the MoveAction
				if u.AvailMoveActions > 0 {
					// Only generate an ArtifactSwitchAction if the current
					// tiles are suitable for both permanents
					if t.Permanent != nil && t.Permanent.Card().Type.IsArtifact() &&
						t.IsSuitableForCard(u.Card()) && u.Tile().IsSuitableForCard(t.Permanent.Card()) {
						actions = append(actions, newArtifactSwitchAction(u, t.Permanent))
					}
				}
			}
		}
	}

	return actions
}

func (u *Unit) AvailFreeActions() (actions []Action) {
	for _, p := range u.FreeActions {
		actions = append(actions, p)
	}
	return
}

func (u *Unit) CurrentlyAvailActions() (actions []Action) {
	s := u.Controller().gameState
	if s.IsActivePlayer(u.Controller()) && s.ActivePhase() == Phases.ActionPhase {
		actions = append(actions, u.AvailSlowActions()...)
	}
	actions = append(actions, u.AvailFreeActions()...)
	return
}

func (u *Unit) AvailActions() (actions []Action) {
	actions = append(actions, u.AvailSlowActions()...)
	actions = append(actions, u.AvailFreeActions()...)
	return
}

func (u *Unit) onPile(containing Permanent) {
	u.permanentBase.onPile(containing)
	if baseUnit, ok := containing.(*Unit); ok {
		baseUnitAttackRange := baseUnit.Attack.MaxRange()
		for r, a := range u.Attack.attacks {
			if r > baseUnitAttackRange-1 {
				baseUnit.Attack.attacks = append(baseUnit.Attack.attacks, a)
			} else {
				baseUnit.Attack.attacks[r] += a
			}
		}
	}
}

func (u *Unit) onUnpile(containing Permanent) {
	u.permanentBase.onUnpile(u)
	if baseUnit, ok := containing.(*Unit); ok {
		for r, a := range baseUnit.Attack.attacks {
			if a == u.Attack.attacks[r] {
				// Remove all further attacks since they must all be from the
				// dropped unit
				baseUnit.Attack.attacks = baseUnit.Attack.attacks[:r]
				break
			} else {
				baseUnit.Attack.attacks[r] -= u.Attack.attacks[r]
			}
		}
	}
}

func (u *Unit) onDrop(containing Permanent) {
	u.onUnpile(containing)
}

func (u *Unit) removeFullAction(tag string) {
	for i, fa := range u.FullActions {
		if fa.tag != tag {
			continue
		}
		u.FullActions[i] = u.FullActions[len(u.FullActions)-1]
		u.FullActions = u.FullActions[:len(u.FullActions)-1]
		break
	}
}

func (u *Unit) adjustDamage(damage int) {
	if damage > 0 && u.Marks(UnitMarks.Ward) > 0 {
		u.adjustMarks(UnitMarks.Ward, -1)
		return
	}

	u.permanentBase.adjustDamage(damage)
}

func (u *Unit) equip(e *Equipment) {
	if e.containingPerm != nil {
		removePermanentFromPile(e.containingPerm, e)
	} else {
		leaveTileOrPile(e)
	}
	addPermanentToPile(u, e)
}