package game

import (
	"fmt"
	"strconv"

	"thehouseoficarus/internal/behavior"
	"thehouseoficarus/internal/color"
	"thehouseoficarus/internal/net"
	"thehouseoficarus/internal/player"
)

// effectScope controls which subset of a StepAction's effects applyStepAction
// will fire. The three scopes cover the three callers of the unified executor:
//
//   - scopePlayer:     inline triggers (talk nodes, on_use, on_look,
//                      on_kill, exit traversal). Receives all
//                      player-targeted effects (flags, items, heal, credits,
//                      teleport, aps_node). Broadcast is allowed (so on_kill
//                      can announce to the room); broadcast_global is not
//                      (there's no per-tick sequence owner to author it).
//   - scopePlayerSeq:  on_enter steps + trigger player sequences. Same as
//                      scopePlayer plus broadcast_global (a sequence can
//                      shout to the whole world) and spawn_mob/despawn_mob
//                      (player-owned transient mobs).
//   - scopeGlobal:     trigger global sequences. No player is involved; only
//                      broadcasts, global flag mutations, and world-owned
//                      spawn/despawn fire.
type effectScope int

const (
	scopePlayer effectScope = iota
	scopePlayerSeq
	scopeGlobal
)

// applyStepAction is the single effect executor used by every conditional
// interaction and timed step in the game: talk nodes, talk options,
// on_use/on_look/on_kill interactions, exit traversal, on_enter steps, and
// room/global trigger sequences. The previous fireEnterStep /
// executeTriggerStep / executeGlobalTriggerStep / applyNodeAction executors
// are all thin wrappers over this one.
//
// flagValue (may be nil) is substituted into %v in any message/broadcast
// template; playerName (derived from p when non-nil) is substituted into %p.
// scopeGlobal ignores p entirely.
//
// The fixed effect order (matching the original executors, normalized):
//   1. message (player/seq scopes — skipped for scopeGlobal)
//   2. broadcast → all in room (seq/global scopes)
//   3. broadcast_global → all online (seq/global scopes)
//   4. set_global_flags (scopeGlobal only; player scopes handle globals in step 5
//      via applyFlagMutations so they aren't set twice)
//   5. set_player_flags (player/seq scopes; cascades via setPlayerFlag)
//   6. take_item (player/seq scopes)
//   7. give_item (player/seq scopes; honors 28-slot inventory limit)
//   8. heal (player/seq scopes; clamps to MaxHP)
//   9. credits (player/seq scopes; negative is gated by affordability)
//  10. spawn_mob (seq/global scopes; player-owned when seq)
//  11. despawn_mob (seq/global scopes; filtered by owner when seq)
//  12. teleport (player/seq scopes; re-runs look + on_enter of target)
//  13. aps_node (player/seq scopes; marks "aps_node_<roomID>" player flag)

// writePlayerMessage expands the message template (player name, flag value),
// colorizes inline {spec}text{/} tags under the caller's color mode, and writes
// it to sess. It is the single path used by every per-player message emission
// in the interaction system (applyStepAction step 1, applyInteraction's
// Interaction.Message, completeMove's on_traverse Message, and
// advanceUseInteraction's d.Message) so color tags render consistently.
func (g *Game) writePlayerMessage(sess *net.Session, msg string, playerName string, flagValue any) {
	if sess == nil || msg == "" {
		return
	}
	rendered := expandTemplate(msg, playerName, flagValue)
	seqSpec := g.resolveColor(sess, "sequence")
	mode := g.colorMode(sess)
	rendered = color.ExpandTagsDefault(mode, seqSpec, rendered)
	sess.WriteLine(rendered)
}

func (g *Game) applyStepAction(sess *net.Session, p *player.Player, step *behavior.StepAction, roomID int, sc effectScope, flagValue any) {
	if step == nil {
		return
	}

	var playerName string
	if p != nil {
		playerName = p.Name
	}

	// 1. message — direct to the triggering session. Skipped for scopeGlobal
	// (no per-player session is the target).
	if sc != scopeGlobal {
		g.writePlayerMessage(sess, step.Message, playerName, flagValue)
	}

	// 2 & 3. broadcast / broadcast_global — re-render color tags per recipient
	// so each player sees them in their own color mode.
	broadcastSpec := g.resolveColor(nil, "broadcast")
	if (sc == scopePlayerSeq || sc == scopeGlobal) && g.Hub != nil {
		if step.Broadcast != "" {
			raw := expandTemplate(step.Broadcast, playerName, flagValue)
			for _, other := range g.Hub.PlayersInRoom(roomID) {
				otherMode := g.colorMode(other)
				rendered := color.ExpandTagsDefault(otherMode, broadcastSpec, raw)
				other.WriteLine(g.colorize(other, "broadcast", rendered))
			}
		}
		if step.BroadcastGlobal != "" {
			raw := expandTemplate(step.BroadcastGlobal, playerName, flagValue)
			for _, other := range g.Hub.AllSessions() {
				if other.Player == nil {
					continue
				}
				otherMode := g.colorMode(other)
				rendered := color.ExpandTagsDefault(otherMode, broadcastSpec, raw)
				other.WriteLine(g.colorize(other, "broadcast", rendered))
			}
		}
	}

	// 4. set_global_flags — scopeGlobal has no player, so it sets globals here
	// (cascades via OnChange). Player scopes handle globals in step 5 alongside
	// player flags (applyFlagMutations sets both atomically per-scope), avoiding
	// a redundant second SetAll.
	if sc == scopeGlobal && len(step.SetGlobalFlags) > 0 {
		g.GlobalFlags.SetAll(step.SetGlobalFlags)
	}

	// Global triggers have no player — stop after the world-scoped effects.
	if sc == scopeGlobal {
		if step.SpawnMob != nil {
			g.spawnWorldTriggerMob(step.SpawnMob, roomID)
		}
		if step.DespawnMob != "" {
			g.despawnTriggerMobs(step.DespawnMob, "")
		}
		return
	}

	// Everything below needs a player.
	if p == nil {
		return
	}

	// 5. set_player_flags — cascade via setPlayerFlag (may synchronously re-fire
	// other player-flag triggers).
	if len(step.SetGlobalFlags) > 0 || len(step.SetPlayerFlags) > 0 {
		g.applyFlagMutations(p, step.SetGlobalFlags, step.SetPlayerFlags)
		g.AccountStore.SaveCharacter(p)
	}

	// 6. take_item
	if step.TakeItem != "" {
		if p.HasItem(step.TakeItem) {
			p.RemoveItem(step.TakeItem, 1)
			g.AccountStore.SaveCharacter(p)
		}
	}

	// 7. give_item
	if step.GiveItem != "" {
		slot := p.FirstFreeSlot()
		if slot == -1 {
			if sess != nil {
				sess.WriteLine("Your inventory is too full to receive that.")
			}
		} else {
			p.SetInvSlot(slot, &player.InventorySlot{ItemID: step.GiveItem, Quantity: 1})
			g.AccountStore.SaveCharacter(p)
		}
	}

	// 8. heal
	if step.Heal > 0 {
		p.HP += step.Heal
		if maxHP := p.MaxHP(); p.HP > maxHP {
			p.HP = maxHP
		}
		g.AccountStore.SaveCharacter(p)
		if sess != nil {
			sess.WriteLine(fmt.Sprintf("You regain %d hitpoints.", step.Heal))
		}
	}

	// 9. credits (signed; negative is gated)
	if step.Credits != 0 {
		if step.Credits < 0 {
			if p.Credits >= -step.Credits {
				p.Credits += step.Credits
				g.AccountStore.SaveCharacter(p)
			} else if sess != nil {
				sess.WriteLine(fmt.Sprintf("You don't have enough credits. (Need %d, have %d)", -step.Credits, p.Credits))
			}
		} else {
			p.Credits += step.Credits
			g.AccountStore.SaveCharacter(p)
		}
	}

	// 10/11. spawn_mob / despawn_mob — sequence-only effects. Inline callers
	// (scopePlayer) leave these empty; nothing fires.
	if sc == scopePlayerSeq && step.SpawnMob != nil {
		g.spawnTriggerMob(sess, p, step.SpawnMob, roomID)
	}
	if sc == scopePlayerSeq && step.DespawnMob != "" {
		g.despawnTriggerMobs(step.DespawnMob, p.Name)
	}

	// 12. teleport
	if step.Teleport > 0 && sess != nil {
		g.teleportPlayer(sess, p, step.Teleport)
	}

	// 13. aps_node — marks this current room as a discovered APS node on the
	// player's datapad. Kept as a dedicated effect because the room-id
	// substitution is dynamic (the player's current room), not expressible
	// via a static set_player_flags entry.
	if step.ApsNode {
		g.setPlayerFlag(p, "aps_node_"+strconv.Itoa(p.RoomID), true)
		g.AccountStore.SaveCharacter(p)
	}
}

// applyNodeAction is the inline-only convenience wrapper used by talk nodes,
// talk options, and any historical caller that holds a *NodeAction rather
// than a *StepAction. It wraps the NodeAction in a StepAction (sequence-only
// fields empty) and dispatches to applyStepAction with scopePlayer scoped
// to the player's current room.
func (g *Game) applyNodeAction(sess *net.Session, na *behavior.NodeAction) {
	p := sess.Player
	if p == nil || na == nil {
		return
	}
	g.applyStepAction(sess, p, &behavior.StepAction{NodeAction: *na}, p.RoomID, scopePlayer, nil)
}

// applyInteraction fires the first matching entry in a list of conditional
// interactions (on_use, on_look, on_kill, exit traversal). Returns true when
// an entry matched and fired. The action runs at scopePlayer (or scopePlayerSeq
// if allowSeq is set, for on_kill which may broadcast/spawn). The
// interaction's Message is written to the player first (if non-empty), then
// the Action fires via applyStepAction.
//
// itemMatch (optional) gates entries that carry an item_id: for on_look it
// requires the player to have the item in inventory; for on_kill it requires
// the player to be wielding it. nil means the item_id field is ignored (used
// by callers without an item filter, e.g. exit traversal). Entries are walked
// top-to-bottom; the first whose item filter, Condition, and the first-match-
// wins rule all pass fires.
func (g *Game) applyInteraction(sess *net.Session, p *player.Player, list []behavior.Interaction, roomID int, allowSeq bool, itemMatch func(string) bool) bool {
	sc := scopePlayer
	if allowSeq {
		sc = scopePlayerSeq
	}
	for _, it := range list {
		if it.Item != "" && itemMatch != nil && !itemMatch(it.Item) {
			continue
		}
		if it.Condition != nil && !g.checkCondition(sess, it.Condition) {
			continue
		}
		g.writePlayerMessage(sess, it.Message, p.Name, nil)
		g.applyStepAction(sess, p, it.Action, roomID, sc, nil)
		return true
	}
	return false
}