import type { BattleSession } from 'db://assets/mx/module/battle';
import type { EntityId } from 'db://assets/mx/module/ecs';
import { createAbilityContext } from 'db://assets/mx/module/battle/combat/AbilityContext';
import { EntityTag, HealthComp, TagComp } from 'db://assets/mx/module/battle';
import type { SkillPresentationContext } from '../skill/SkillPresentationTypes';
import { SkillPresentationEnv } from '../skill/SkillPresentationEnv';

/** Boss 不可被秒杀/斩杀 */
export function isBossEntity(entityId: EntityId, session?: BattleSession | null): boolean {
    const s = session ?? SkillPresentationEnv.getBattleSession();
    if (!s?.world.isAlive(entityId)) return false;
    return !!s.world.getComponent(entityId, TagComp)?.tags.includes(EntityTag.Boss);
}

/** 聚合已选词条 skill_special（含普攻 up_type=1） */
export function readSkillSpecialWan(caster: EntityId, specialType: number): number {
    let best = 0;
    for (const raw of SkillPresentationEnv.getSkillSpecials(caster)) {
        for (const seg of String(raw).split(';')) {
            const part = seg.trim();
            if (!part) continue;
            const nums = part.split(',').map(Number);
            if ((nums[0] ?? 0) !== specialType || nums.length < 2) continue;
            best = Math.max(best, Math.max(0, Number(nums[1]) || 0));
        }
    }
    return best;
}

function dealExecuteDamage(
    ctx: SkillPresentationContext,
    targetId: EntityId,
    damageType: string,
): boolean {
    const session = SkillPresentationEnv.getBattleSession();
    if (!session?.world.isAlive(targetId)) return false;
    const floatPos = SkillPresentationEnv.resolveKillFloaterWorldPos(targetId);
    const abilityCtx = createAbilityContext(session, ctx.caster, ctx.abilityId, [targetId]);
    abilityCtx.level = ctx.level;
    const amount = session.damage.dealToTarget(ctx.caster, targetId, {
        percentMaxHpWan: 10000,
        scale: 1,
        damageType,
        skillAtkBuff1: '',
        skillAtkBuff2: '',
    }, abilityCtx);
    if (amount > 0 && floatPos) {
        SkillPresentationEnv.playKillFloater(floatPos, damageType);
    }
    return amount > 0;
}

/**
 * 会话侧斩杀/秒杀扣血。
 * @param session 战斗会话
 * @param caster 来源
 * @param target 目标
 * @param damageType 伤害类型
 * @param fromPassiveResult 是否被动 result
 */
function dealExecuteDamageSession(
    session: BattleSession,
    caster: EntityId,
    target: EntityId,
    damageType: string,
    fromPassiveResult: boolean,
): boolean {
    if (!session.world.isAlive(target)) return false;
    const floatPos = SkillPresentationEnv.resolveKillFloaterWorldPos(target);
    const abilityCtx = createAbilityContext(session, caster, `passive_execute_${damageType}`, [target]);
    const amount = session.damage.dealToTarget(caster, target, {
        percentMaxHpWan: 10000,
        scale: 1,
        damageType,
        fromPassiveResult,
        skillAtkBuff1: '',
        skillAtkBuff2: '',
    }, abilityCtx);
    if (amount > 0 && floatPos) {
        SkillPresentationEnv.playKillFloater(floatPos, damageType);
    }
    return amount > 0;
}

/** skill_special 类型 10：概率秒杀（Boss 无效） */
export function tryInstantKill(
    ctx: SkillPresentationContext,
    targetId: EntityId,
    killWan: number,
    damageType = 'instant_kill',
): boolean {
    if (killWan <= 0 || isBossEntity(targetId)) return false;
    const rng = SkillPresentationEnv.getBattleRng();
    const roll = (rng?.next() ?? Math.random()) * 10000;
    if (roll >= killWan) return false;
    return dealExecuteDamage(ctx, targetId, damageType);
}

/** skill_special 类型 11：HP 比例斩杀（Boss 无效） */
export function tryExecuteByThreshold(
    ctx: SkillPresentationContext,
    targetId: EntityId,
    thresholdWan: number,
    damageType = 'execute',
): boolean {
    if (thresholdWan <= 0 || isBossEntity(targetId)) return false;
    const session = SkillPresentationEnv.getBattleSession();
    if (!session?.world.isAlive(targetId)) return false;
    const hp = session.world.getComponent(targetId, HealthComp);
    if (!hp || hp.maxHp <= 0) return false;
    if (hp.hp / hp.maxHp > thresholdWan / 10000) return false;
    return dealExecuteDamage(ctx, targetId, damageType);
}

/**
 * 被动 result 16：概率秒杀。
 * @param session 会话
 * @param caster 来源
 * @param target 目标
 * @param killWan 概率万分比
 */
export function tryInstantKillSession(
    session: BattleSession,
    caster: EntityId,
    target: EntityId,
    killWan: number,
): boolean {
    if (killWan <= 0 || isBossEntity(target, session)) return false;
    if (session.rng.next() * 10000 >= killWan) return false;
    return dealExecuteDamageSession(session, caster, target, 'instant_kill', true);
}

/**
 * 被动 result 15：低血量斩杀（可再掷概率）。
 * @param session 会话
 * @param caster 来源
 * @param target 目标
 * @param thresholdWan 血量比例万分比
 * @param chanceWan 斩杀概率万分比
 */
export function tryExecuteByThresholdSession(
    session: BattleSession,
    caster: EntityId,
    target: EntityId,
    thresholdWan: number,
    chanceWan = 10000,
): boolean {
    if (thresholdWan <= 0 || isBossEntity(target, session)) return false;
    if (!session.world.isAlive(target)) return false;
    const hp = session.world.getComponent(target, HealthComp);
    if (!hp || hp.maxHp <= 0) return false;
    if (hp.hp / hp.maxHp > thresholdWan / 10000) return false;
    if (chanceWan < 10000 && session.rng.next() * 10000 >= chanceWan) return false;
    return dealExecuteDamageSession(session, caster, target, 'execute', true);
}