import type { EntityId } from 'db://assets/mx/module/battle/ecs/EntityId';
import type { AbilityContext } from 'db://assets/mx/module/battle/combat/AbilityContext';
import type { Cell } from 'db://assets/mx/module/battle/battlefield/Cell';
import type { UnitDefId, EffectSpec } from 'db://assets/mx/module/battle/config/BattleConfigTypes';
import { BattlePhase } from 'db://assets/mx/module/battle/core/BattlePhase';
import { BattleEventType } from './BattleEventType';

/** 战斗事件联合类型（type 字段必须使用 BattleEventType 枚举） */
export type BattleEvent =
    | { type: BattleEventType.PhaseChanged; phase: BattlePhase; prev: BattlePhase }
    | { type: BattleEventType.UnitPlaced; entity: EntityId; playerId: number; cell: Cell }
    | { type: BattleEventType.UnitSold; entity: EntityId; playerId: number }
    | { type: BattleEventType.AbilityCast; ctx: AbilityContext }
    | {
        type: BattleEventType.PresentationCue;
        caster: EntityId;
        abilityId: string;
        cueId: string;
        params: Record<string, unknown>;
        atMs: number;
        castInstanceId: number;
        targetEntityIds: EntityId[];
    }
    | {
        type: BattleEventType.AbilityCastEnd;
        caster: EntityId;
        abilityId: string;
        castInstanceId: number;
        durationSec: number;
    }
    | { type: BattleEventType.DamageDealt; caster: EntityId; target: EntityId; amount: number; damageType?: string; fromPassiveResult?: boolean }
    | { type: BattleEventType.AttackBefore; caster: EntityId; targets: EntityId[]; abilityId?: string }
    | { type: BattleEventType.HitAfter; caster: EntityId; target: EntityId; amount: number; isCrit: boolean; abilityId?: string; damageType?: string }
    | { type: BattleEventType.BuffApplied; target: EntityId; buffId: string; duration: number; caster: EntityId }
    | { type: BattleEventType.BuffRemoved; target: EntityId; buffId: string }
    | { type: BattleEventType.ProjectileSpawned; projectile: EntityId; caster: EntityId; prefab?: string }
    | { type: BattleEventType.ProjectileHit; projectile: EntityId; caster: EntityId; target: EntityId; hitEffects: EffectSpec[] }
    | { type: BattleEventType.EntityKilled; killer: EntityId; victim: EntityId; damageType?: string; fromPassiveResult?: boolean }
    | { type: BattleEventType.UnitDespawned; entity: EntityId }
    | { type: BattleEventType.WallDamaged; playerId: number; amount: number; remain: number }
    | { type: BattleEventType.WaveStart; waveIndex: number; playerId?: number }
    | { type: BattleEventType.WaveEnd; waveIndex: number; playerId?: number }
    | { type: BattleEventType.UnitSpawned; entity: EntityId; unitDefId: UnitDefId; spawnPort: number; hp: number }
    | { type: BattleEventType.BattleEnd; win: boolean; reason?: string }
    | { type: BattleEventType.Custom; name: string; payload?: unknown };

/** 战斗事件监听器 */
export type BattleEventListener = (event: BattleEvent) => void;

/**
 * 战斗事件工厂
 * 所有 logic → view 的事件须通过此处构造，避免散落字符串字面量。
 */
export const BattleEventFactory = {
    /** @returns 阶段切换事件 */
    phaseChanged(phase: BattlePhase, prev: BattlePhase): BattleEvent {
        return { type: BattleEventType.PhaseChanged, phase, prev };
    },
    /** @returns 单位部署事件 */
    unitPlaced(entity: EntityId, playerId: number, cell: Cell): BattleEvent {
        return { type: BattleEventType.UnitPlaced, entity, playerId, cell };
    },
    /** @returns 单位出售事件 */
    unitSold(entity: EntityId, playerId: number): BattleEvent {
        return { type: BattleEventType.UnitSold, entity, playerId };
    },
    /** @returns 技能施放事件 */
    abilityCast(ctx: AbilityContext): BattleEvent {
        return { type: BattleEventType.AbilityCast, ctx };
    },
    /** @returns 表现 cue 事件（逻辑 → 表现层语义阶段） */
    presentationCue(args: {
        caster: EntityId;
        abilityId: string;
        cueId: string;
        params?: Record<string, unknown>;
        atMs?: number;
        castInstanceId: number;
        targetEntityIds?: EntityId[];
    }): BattleEvent {
        return {
            type: BattleEventType.PresentationCue,
            caster: args.caster,
            abilityId: args.abilityId,
            cueId: args.cueId,
            params: args.params ?? {},
            atMs: args.atMs ?? 0,
            castInstanceId: args.castInstanceId,
            targetEntityIds: args.targetEntityIds ?? [],
        };
    },
    /** @returns 技能施法结束事件 */
    abilityCastEnd(
        caster: EntityId,
        abilityId: string,
        castInstanceId: number,
        durationSec: number,
    ): BattleEvent {
        return {
            type: BattleEventType.AbilityCastEnd,
            caster,
            abilityId,
            castInstanceId,
            durationSec,
        };
    },
    /** @returns 造成伤害事件 */
    damageDealt(caster: EntityId, target: EntityId, amount: number, damageType?: string, fromPassiveResult?: boolean): BattleEvent {
        return { type: BattleEventType.DamageDealt, caster, target, amount, damageType, fromPassiveResult };
    },
    /** @returns 攻击前事件（伤害结算前） */
    attackBefore(caster: EntityId, targets: EntityId[], abilityId?: string): BattleEvent {
        return { type: BattleEventType.AttackBefore, caster, targets, abilityId };
    },
    /** @returns 命中后事件（伤害结算后） */
    hitAfter(caster: EntityId, target: EntityId, amount: number, isCrit: boolean, abilityId?: string, damageType?: string): BattleEvent {
        return { type: BattleEventType.HitAfter, caster, target, amount, isCrit, abilityId, damageType };
    },
    /** @returns Buff 施加事件 */
    buffApplied(target: EntityId, buffId: string, duration: number, caster: EntityId): BattleEvent {
        return { type: BattleEventType.BuffApplied, target, buffId, duration, caster };
    },
    /** @returns Buff 移除事件 */
    buffRemoved(target: EntityId, buffId: string): BattleEvent {
        return { type: BattleEventType.BuffRemoved, target, buffId };
    },
    /** @returns 投射物生成事件 */
    projectileSpawned(projectile: EntityId, caster: EntityId, prefab?: string): BattleEvent {
        return { type: BattleEventType.ProjectileSpawned, projectile, caster, prefab };
    },
    /** @returns 投射物命中事件 */
    projectileHit(projectile: EntityId, caster: EntityId, target: EntityId, hitEffects: EffectSpec[]): BattleEvent {
        return { type: BattleEventType.ProjectileHit, projectile, caster, target, hitEffects };
    },
    /** @returns 实体击杀事件 */
    entityKilled(killer: EntityId, victim: EntityId, damageType?: string, fromPassiveResult?: boolean): BattleEvent {
        return { type: BattleEventType.EntityKilled, killer, victim, damageType, fromPassiveResult };
    },
    /** @returns 实体无击杀结算移除事件 */
    unitDespawned(entity: EntityId): BattleEvent {
        return { type: BattleEventType.UnitDespawned, entity };
    },
    /** @returns 城墙受伤事件 */
    wallDamaged(playerId: number, amount: number, remain: number): BattleEvent {
        return { type: BattleEventType.WallDamaged, playerId, amount, remain };
    },
    /** @returns 波次开始事件 */
    waveStart(waveIndex: number, playerId?: number): BattleEvent {
        return { type: BattleEventType.WaveStart, waveIndex, playerId };
    },
    /** @returns 波次结束事件 */
    waveEnd(waveIndex: number, playerId?: number): BattleEvent {
        return { type: BattleEventType.WaveEnd, waveIndex, playerId };
    },
    /** @returns 怪物生成事件 */
    unitSpawned(entity: EntityId, unitDefId: UnitDefId, spawnPort: number, hp: number): BattleEvent {
        return { type: BattleEventType.UnitSpawned, entity, unitDefId, spawnPort, hp };
    },
    /** @returns 战斗结束事件 */
    battleEnd(win: boolean, reason?: string): BattleEvent {
        return { type: BattleEventType.BattleEnd, win, reason };
    },
    /** @returns 自定义事件 */
    custom(name: string, payload?: unknown): BattleEvent {
        return { type: BattleEventType.Custom, name, payload };
    },
} as const;