/**
 * 糖分突袭 · 视觉特效状态（飘字、粒子、连消横幅、震屏、闪屏）
 * 特效风格参考「开心消消乐」：糖果色星屑、弹性扩散光环、大消除闪屏。
 */
import { ref } from 'vue'

let fxSeq = 0
function nextFxId(prefix) {
    fxSeq += 1
    return `${prefix}-${fxSeq}-${Date.now()}`
}

// 开心消消乐式糖果色板（彩虹爆裂用）
const CANDY_COLORS = ['#FF5E9C', '#FFC93C', '#5BD16A', '#4D9DFF', '#FF8A3D', '#B57BFF', '#FF6F91', '#2FE6C8']
// 星屑字形
const STAR_GLYPHS = ['✦', '✧', '★', '✨']

export function useGameFx() {
    const floatingTexts = ref([])
    const burstParticles = ref([])
    const ripples = ref([])
    const comboBanner = ref({ show: false, text: '', tier: 1 })
    const screenShaking = ref(false)
    const flash = ref({ active: false, color: '#ffffff', opacity: 0 })

    let comboBannerTimer = null
    let shakeTimer = null
    let flashTimer = null
    let flashFadeTimer = null

    function spawnFloatingText(payload) {
        const id = nextFxId('ft')
        floatingTexts.value.push({ id, ...payload })
        const duration = payload.danger ? 1500 : payload.isCombo ? 1400 : 1200
        setTimeout(() => {
            floatingTexts.value = floatingTexts.value.filter((f) => f.id !== id)
        }, duration)
        return id
    }

    /**
     * 糖果爆裂粒子（星屑 + 圆点混合，上抛后受重力下落，带旋转与缓动）。
     * @param {number} cx,cy 爆裂中心（屏幕坐标）
     * @param {string} color 基础颜色
     * @param {number} count 粒子数量
     * @param {object} opts { star, rainbow, gravity, sizeMin, sizeMax, distMin, distMax, life }
     */
    function spawnBurst(cx, cy, color, count = 8, opts = {}) {
        const {
            star = true,
            rainbow = false,
            gravity = 64,
            sizeMin = 8,
            sizeMax = 16,
            distMin = 36,
            distMax = 110,
            life = 850
        } = opts
        const dur = (life / 1000).toFixed(2)

        for (let i = 0; i < count; i++) {
            const id = nextFxId('p')
            const isStar = star && Math.random() < 0.65
            const pSize = Math.random() * (sizeMax - sizeMin) + sizeMin
            const angle = Math.random() * Math.PI * 2
            const distance = Math.random() * (distMax - distMin) + distMin
            const tx = Math.cos(angle) * distance
            // 先上抛、再叠加重力下落，形成喷泉抛物线
            const ty = Math.sin(angle) * distance - distance * 0.35 + gravity
            const half = pSize / 2
            const pColor = rainbow
                ? CANDY_COLORS[Math.floor(Math.random() * CANDY_COLORS.length)]
                : color
            const rot = Math.random() * 720 - 360
            const glyph = isStar ? STAR_GLYPHS[Math.floor(Math.random() * STAR_GLYPHS.length)] : ''

            const particle = {
                id,
                left: cx - half,
                top: cy - half,
                size: pSize,
                color: pColor,
                char: glyph,
                opacity: 1,
                transform: 'scale(0.4) rotate(0deg)',
                transition: 'none'
            }
            burstParticles.value.push(particle)

            setTimeout(() => {
                particle.transition =
                    `left ${dur}s cubic-bezier(0.16,0.7,0.3,1), top ${dur}s cubic-bezier(0.3,0.1,0.4,1), opacity ${dur}s ease-in, transform ${dur}s ease-out`
                particle.left = cx - half + tx
                particle.top = cy - half + ty
                particle.opacity = 0
                particle.transform = `scale(${isStar ? 1.15 : 0.5}) rotate(${rot}deg)`
            }, 16)

            setTimeout(() => {
                burstParticles.value = burstParticles.value.filter((p) => p.id !== id)
            }, life + 80)
        }
    }

    /**
     * 弹性扩散发光光环（开心消消乐式的扩散光圈）。
     * @param {object} opts { thickness, life }
     */
    function spawnRipple(cx, cy, color, tier = 1, opts = {}) {
        const id = nextFxId('rp')
        const size = 36 + tier * 18
        const { thickness = Math.max(3, tier + 2), life = 600 } = opts
        ripples.value.push({
            id,
            left: cx,
            top: cy,
            size,
            color,
            thickness,
            opacity: 0.95
        })
        setTimeout(() => {
            ripples.value = ripples.value.filter((r) => r.id !== id)
        }, life)
    }

    /**
     * 全屏闪光（大消除瞬间的爆闪），先点亮再淡出。
     */
    function triggerFlash(color = '#ffffff', intensity = 0.5, life = 280) {
        if (flashFadeTimer) clearTimeout(flashFadeTimer)
        if (flashTimer) clearTimeout(flashTimer)
        flash.value = { active: true, color, opacity: intensity }
        flashFadeTimer = setTimeout(() => {
            flash.value = { ...flash.value, opacity: 0 }
        }, 24)
        flashTimer = setTimeout(() => {
            flash.value = { active: false, color, opacity: 0 }
        }, life)
    }

    function showComboBanner(chain, points) {
        if (chain <= 1) return
        const tier = chain >= 4 ? 3 : chain >= 3 ? 2 : 1
        comboBanner.value = {
            show: true,
            text: `连消 ×${chain}  +${points}`,
            tier
        }
        if (comboBannerTimer) clearTimeout(comboBannerTimer)
        comboBannerTimer = setTimeout(() => {
            comboBanner.value = { ...comboBanner.value, show: false }
        }, 1100)
    }

    function triggerShake(intensity = 1) {
        screenShaking.value = true
        if (shakeTimer) clearTimeout(shakeTimer)
        shakeTimer = setTimeout(() => {
            screenShaking.value = false
        }, intensity >= 2 ? 420 : 280)
    }

    function clearAll() {
        floatingTexts.value = []
        burstParticles.value = []
        ripples.value = []
        comboBanner.value = { show: false, text: '', tier: 1 }
        screenShaking.value = false
        flash.value = { active: false, color: '#ffffff', opacity: 0 }
    }

    return {
        floatingTexts,
        burstParticles,
        ripples,
        comboBanner,
        screenShaking,
        flash,
        spawnFloatingText,
        spawnBurst,
        spawnRipple,
        showComboBanner,
        triggerShake,
        triggerFlash,
        clearAll
    }
}