package game

import (
	"regexp"
	"strconv"
	"strings"

	"muhq.space/muhqs-game/go/log"
)

type dynamicCardImplementation struct {
	card           *Card
	spawnTilesFunc func(*LocalState, *Player) []*Tile
	genFullActions func(*Unit) []*FullAction
	genFreeActions func(Permanent) []*FreeAction

	targetDesc TargetDesc

	_stateBasedActions func(*LocalState, Permanent)

	_additionalPlayCosts func(*PlayAction) ActionCostFunc
	_additionalSpawnsFor func(Permanent, CardType) []*Tile

	_onEntering func(*Tile)
	_onLeaving  func(*Tile)
	_onPlay     func(*PlayAction)
	_onETB      func(*LocalState, Permanent)
	_onPile     func(Permanent)
	_onUnpile   func(Permanent)
	_onDrop     func(Permanent)
	_onUpkeep   func(Permanent)
}

func (impl *dynamicCardImplementation) spawnTiles(s *LocalState, p *Player) []*Tile {
	if impl.spawnTilesFunc != nil {
		return impl.spawnTilesFunc(s, p)
	}
	return nil
}

func (impl *dynamicCardImplementation) fullActions(u *Unit) []*FullAction {
	if impl.genFullActions != nil {
		return impl.genFullActions(u)
	}
	return nil
}

func (impl *dynamicCardImplementation) freeActions(p Permanent) []*FreeAction {
	if impl.genFreeActions != nil {
		return impl.genFreeActions(p)
	}
	return nil
}

func (impl *dynamicCardImplementation) playTargets() TargetDesc {
	return impl.targetDesc
}

func (impl *dynamicCardImplementation) stateBasedActions(s *LocalState, p Permanent) {
	if impl._stateBasedActions != nil {
		impl._stateBasedActions(s, p)
	}
}

func (impl *dynamicCardImplementation) additionalPlayCosts(a *PlayAction) ActionCostFunc {
	if impl._additionalPlayCosts != nil {
		return impl._additionalPlayCosts(a)
	}
	return nil
}

func (impl *dynamicCardImplementation) additionalSpawnsFor(p Permanent, ct CardType) []*Tile {
	if impl._additionalSpawnsFor != nil {
		return impl._additionalSpawnsFor(p, ct)
	}
	return nil
}

func (impl *dynamicCardImplementation) onEntering(t *Tile) {
	if impl._onEntering != nil {
		impl._onEntering(t)
	}
}

func (impl *dynamicCardImplementation) onLeaving(t *Tile) {
	if impl._onLeaving != nil {
		impl._onLeaving(t)
	}
}

func (impl *dynamicCardImplementation) onPlay(a *PlayAction) {
	if impl._onPlay != nil {
		impl._onPlay(a)
	}
}

func (impl *dynamicCardImplementation) onETB(s *LocalState, p Permanent) {
	if impl._onETB != nil {
		impl._onETB(s, p)
	}
}

func (impl *dynamicCardImplementation) onPile(p Permanent) {
	if impl._onPile != nil {
		impl._onPile(p)
	}
}

func (impl *dynamicCardImplementation) onUnpile(p Permanent) {
	if impl._onUnpile != nil {
		impl._onUnpile(p)
	}
}

func (impl *dynamicCardImplementation) onDrop(p Permanent) {
	if impl._onDrop != nil {
		impl._onDrop(p)
	}
}

func (impl *dynamicCardImplementation) onUpkeep(p Permanent) {
	if impl._onUpkeep != nil {
		impl._onUpkeep(p)
	}
}

func newParsedCardImplementation(c *Card) *dynamicCardImplementation {
	impl := &dynamicCardImplementation{card: c}
	for _, effect := range c.getEffects() {
		impl.parseEffect(effect)
	}

	for _, fullAction := range c.getCanonicalValues("full_action") {
		impl.parseFullAction(fullAction)
	}

	return impl
}

var additionalActionRegex = regexp.MustCompile(`has.*additional (.*) action`)

func (impl *dynamicCardImplementation) parseEffect(effect string) {
	if strings.Contains(effect, "can be played") {
		impl.parsePlayModification(effect)
	}

	if m := additionalActionRegex.FindStringSubmatch(effect); m != nil {
		impl.parseAdditionalAction(effect, m)
	}

	if m := freeActionRegex.FindStringSubmatch(effect); m != nil {
		impl.parseFreeAction(m[1], m[2])
	}

	// TODO: support gets and has effects
	if strings.Contains(effect, "equipped unit gets") {
		impl.parseEquipmentGetEffect(effect)
	}
	if strings.Contains(effect, "equipped unit has") {
		impl.parseEquipmentHasEffect(effect)
	}
}

func (impl *dynamicCardImplementation) parseFullAction(fullAction string) {
	var resolveProtos []ActionFuncPrototype
	gainRessourceRegex := regexp.MustCompile(`gain [1-9][0-9]* resource`)

	if find := gainRessourceRegex.Find([]byte(fullAction)); find != nil {
		tokens := strings.SplitN(string(find), " ", 3)
		gain, err := strconv.Atoi(tokens[1])
		if err != nil {
			log.Panicf("Failed to parse resource gain full action: %s", err)
		}

		resolveProto := func(a Action) ActionResolveFunc {
			u := a.Source().(*Unit)
			return func(*LocalState) {
				u.controller.gainResource(gain)
			}
		}
		resolveProtos = append(resolveProtos, resolveProto)
	}

	if resolveProtos != nil {
		impl.genFullActions = func(u *Unit) []*FullAction {
			fullActions := make([]*FullAction, 0, len(resolveProtos))

			for _, proto := range resolveProtos {
				fullActions = append(fullActions, newFullAction(u, proto, ""))
			}

			return fullActions
		}
	}
}

var freeActionRegex = regexp.MustCompile(`([^:]*):(.*)`)

func (impl *dynamicCardImplementation) parseFreeAction(cost, action string) {
	log.Error("Parsing free actions is not implemented yet")
}

func parseUnitConstrain(constrain string) func(ctx any, u *Unit) bool {
	enemy := strings.Contains(constrain, "enemy")
	if enemy {
		return func(ctx any, e *Unit) bool {
			p := ctx.(*Player)
			return p.IsEnemy(e.Controller())
		}
	} else {
		log.Error("Only enemy unit constrains are implemented yet")
	}

	return nil
}

func parseLocation(location string) func(any, *LocalState) []*Tile {
	r := -1
	var what string
	if strings.Contains(location, "on") {
		r = 0
		tokens := strings.SplitN(location, "on ", 2)
		what = tokens[1]

	} else if strings.Contains(location, "next to") {
		r = 1
		tokens := strings.SplitN(location, "next to ", 2)
		what = tokens[1]

	} else if strings.Contains(location, "in range") {
		tokens := strings.SplitN(location, "in range ", 2)
		afterRangePattern := tokens[1]

		var rangeStr string
		tokens = strings.SplitN(afterRangePattern, " ", 2)
		rangeStr, what = tokens[0], tokens[1]

		var err error
		r, err = strconv.Atoi(rangeStr)
		if err != nil {
			log.Panicf("Unsupported range pattern \"%s\" in \"%s\"", "range "+rangeStr, location)
		}
	}

	if r == -1 || what == "" {
		return nil
	}

	if strings.Contains(what, "unit") {
		constrainFunc := parseUnitConstrain(what)
		if constrainFunc != nil {
			return func(ctx any, s *LocalState) []*Tile {
				origins := s.Map().FilterTiles(func(t *Tile) bool {
					if t.Permanent != nil &&
						t.Permanent.Card().Type == CardTypes.Unit &&
						constrainFunc(ctx, t.Permanent.(*Unit)) {
						return true
					}
					return false
				})

				if r == 0 {
					return origins
				} else {
					tiles := []*Tile{}
					for _, origin := range origins {
						tiles = append(tiles, TilesInRangeFromOrigin(s.Map(), origin.Position, r)...)
					}
					return tiles
				}
			}
		}
	}
	log.Error("Only unit location constrains are implemented yet")
	return nil
}

func (impl *dynamicCardImplementation) parsePlayModification(effect string) {
	tokens := strings.SplitN(effect, " can be played ", 2)
	what, how := tokens[0], tokens[1]
	if what == strings.ToLower(impl.card.Name) {
		if locationFunc := parseLocation(how); locationFunc != nil {
			impl.spawnTilesFunc = func(p *LocalState, s *Player) []*Tile { return locationFunc(s, p) }
		} else {
			log.Error("Play modification other than locations are not implemented ")
		}
	} else {
		log.Error("Play modification for other cards are not implemented")
	}
}

func (impl *dynamicCardImplementation) parseAdditionalAction(effect string, matches []string) {
	log.Debug("additional action matches:", "matches", matches)
	switch matches[1] {
	case "attack":
		impl._onUpkeep = func(p Permanent) { u := p.(*Unit); u.AvailAttackActions = u.AvailAttackActions + 1 }
	case "move":
		impl._onUpkeep = func(p Permanent) { u := p.(*Unit); u.AvailMoveActions = u.AvailMoveActions + 1 }
	default:
		log.Warn("unhandled action", "action", matches[1])
	}
}

func (impl *dynamicCardImplementation) parseEquipmentGetEffect(effect string) {
	tokens := strings.SplitAfterN(effect, "equipped unit gets ", 2)
	tokens = tokens[1:]

	tokens = strings.Split(tokens[0], " and ")

	var (
		apply  []func(Permanent)
		remove []func(Permanent)
	)

	for _, token := range tokens {
		x, err := parseXEffect(token)
		if err == nil {
			if strings.Contains(x.raw, "movement") {
				apply = append(apply, func(p Permanent) { adjustMovement(p, x.x) })
				remove = append(apply, func(p Permanent) { adjustMovement(p, -1*x.x) })
			} else if strings.Contains(x.raw, "melee") {
				apply = append(apply, func(p Permanent) { adjustMelee(p, x.x) })
				remove = append(apply, func(p Permanent) { adjustMelee(p, -1*x.x) })
			} else if strings.Contains(x.raw, "health") {
				apply = append(apply, func(p Permanent) { adjustHealth(p, x.x) })
				remove = append(apply, func(p Permanent) { adjustHealth(p, -1*x.x) })
			} else if strings.Contains(x.raw, "armor") {
				apply = append(apply, func(p Permanent) { p.addTmpEffect(token) })
				remove = append(apply, func(p Permanent) { p.removeTmpEffect(token) })
			}
		}
	}

	if len(apply) == 0 {
		return
	}

	impl._onPile = func(p Permanent) {
		for _, a := range apply {
			a(p)
		}
	}
	impl._onUnpile = func(p Permanent) {
		for _, r := range remove {
			r(p)
		}
	}
}

func (impl *dynamicCardImplementation) parseEquipmentHasEffect(effect string) {
	tokens := strings.SplitAfterN(effect, "equipped unit has ", 2)
	tokens = tokens[1:]

	tokens = strings.Split(tokens[0], " and ")
	if len(tokens) == 0 {
		return
	}

	impl._onPile = func(p Permanent) {
		for _, token := range tokens {
			p.addTmpEffect(token)
		}
	}
	impl._onUnpile = func(p Permanent) {
		for _, token := range tokens {
			p.removeTmpEffect(token)
		}
	}
}