import { effectScope, nextTick, type EffectScope } from 'vue'
import { afterEach, describe, expect, it, vi } from 'vitest'
import { useTheme } from './useTheme'
import { readFileSync } from 'node:fs'

let scope: EffectScope | undefined
afterEach(() => {
    scope?.stop()
    scope = undefined
    localStorage.clear()
    delete document.documentElement.dataset.theme
    document.documentElement.style.colorScheme = ''
    vi.unstubAllGlobals()
    vi.restoreAllMocks()
})

/** 可控系统主题，验证跟随模式与事件清理，不依赖测试机器偏好。 */
function setup(dark = false) {
    const listeners = new Set<(event: MediaQueryListEvent) => void>()
    vi.stubGlobal('matchMedia', () => ({
        matches: dark,
        addEventListener: (_: string, listener: (event: MediaQueryListEvent) => void) => listeners.add(listener),
        removeEventListener: (_: string, listener: (event: MediaQueryListEvent) => void) => listeners.delete(listener)
    }))
    scope = effectScope()
    const state = scope.run(useTheme)!
    return {
        ...state,
        listeners,
        change: (matches: boolean) => listeners.forEach(listener => listener({ matches } as MediaQueryListEvent))
    }
}

/** 将十六进制颜色换算为 sRGB 相对亮度。 */
function luminance(hex: string) {
    const channels = [1, 3, 5].map(index => {
        const value = parseInt(hex.slice(index, index + 2), 16) / 255
        return value <= 0.04045 ? value / 12.92 : ((value + 0.055) / 1.055) ** 2.4
    })
    return channels[0]! * 0.2126 + channels[1]! * 0.7152 + channels[2]! * 0.0722
}

/** 检查主题文字对比度，避免绿色按钮和浅色选中项难以辨认。 */
function contrast(foreground: string, background: string) {
    const values = [luminance(foreground), luminance(background)]
    return (Math.max(...values) + 0.05) / (Math.min(...values) + 0.05)
}

describe('微信风格明暗主题', () => {
    it('默认跟随系统并实时响应，销毁时移除监听', async () => {
        const state = setup()
        expect(state.preference.value).toBe('system')
        expect(document.documentElement.dataset.theme).toBe('light')
        state.change(true)
        await nextTick()
        expect(state.isDark.value).toBe(true)
        expect(document.documentElement.style.colorScheme).toBe('dark')
        expect(state.listeners.size).toBe(1)
        scope!.stop()
        expect(state.listeners.size).toBe(0)
    })

    it('手动选择优先于系统，并持久化到下一次挂载', async () => {
        const state = setup(true)
        state.preference.value = 'light'
        await nextTick()
        state.change(true)
        await nextTick()
        expect(state.isDark.value).toBe(false)
        expect(localStorage.getItem('drama-studio-theme')).toBe('light')
        scope!.stop()
        const restored = setup(true)
        expect(restored.preference.value).toBe('light')
        expect(restored.theme.value).toBeNull()
    })

    it('深浅模式同时更新 Naive 主题和业务颜色标记', async () => {
        const state = setup()
        expect(state.overrides.value.common?.primaryColor).toBe('#07c160')
        expect(state.overrides.value.common?.bodyColor).toBe('#ededed')
        state.preference.value = 'dark'
        await nextTick()
        expect(state.theme.value?.name).toBe('dark')
        expect(state.overrides.value.common?.primaryColor).toBe('#07c160')
        expect(state.overrides.value.common?.bodyColor).toBe('#111111')
        expect(state.overrides.value.Button?.textColorPrimary).toBe('#082b17')
        expect(document.documentElement.dataset.theme).toBe('dark')
    })

    it.each([false, true])('明暗模式 %s 的组件表面、语义色与业务 CSS 一致，主要文字保持可读', dark => {
        const state = setup(dark)
        const { common, Menu, Button, Layout } = state.overrides.value
        const css = readFileSync('src/admin.css', 'utf8')
        const lightTokens = css.match(/:root\s*\{([^}]+)\}/)![1]!
        const darkTokens = css.match(/:root\[data-theme='dark'\]\s*\{([^}]+)\}/)![1]!
        const tokens = Object.fromEntries(
            [...(lightTokens + (dark ? darkTokens : '')).matchAll(/--app-([\w-]+):\s*(#[\da-f]+);/g)].map(match => [
                match[1],
                match[2]
            ])
        )
        expect(common).toMatchObject({
            bodyColor: tokens.body,
            cardColor: tokens.surface,
            modalColor: tokens.surface,
            tableColor: tokens.surface,
            inputColor: tokens.surface,
            borderColor: tokens.border,
            textColor1: tokens.ink,
            textColor3: tokens.muted,
            primaryColor: tokens.accent,
            successColor: tokens.success,
            errorColor: tokens.danger
        })
        expect(Layout).toMatchObject({ color: tokens.body, headerColor: tokens.surface, siderColor: tokens.subtle })
        expect(Menu).toMatchObject({ itemColorActive: tokens.selected, itemTextColorActive: tokens['accent-text'] })
        expect(Button?.textColorPrimary).toBe(tokens['on-accent'])
        for (const background of [common!.primaryColor!, common!.primaryColorHover!, common!.primaryColorPressed!]) {
            expect(contrast(String(Button!.textColorPrimary), background)).toBeGreaterThanOrEqual(4.5)
        }
        expect(contrast(tokens.ink!, tokens.surface!)).toBeGreaterThanOrEqual(4.5)
        expect(contrast(tokens.muted!, tokens.subtle!)).toBeGreaterThanOrEqual(4.5)
        expect(contrast(tokens['accent-text']!, tokens.selected!)).toBeGreaterThanOrEqual(4.5)
    })

    it('系统切换时浏览器主题色与页面同步', async () => {
        const meta = document.createElement('meta')
        meta.name = 'theme-color'
        document.head.appendChild(meta)
        try {
            const state = setup()
            expect(meta.content).toBe('#ededed')
            state.change(true)
            await nextTick()
            expect(meta.content).toBe('#111111')
            state.preference.value = 'light'
            await nextTick()
            expect(meta.content).toBe('#ededed')
        } finally {
            meta.remove()
        }
    })

    it('无效存储回退系统模式', () => {
        localStorage.setItem('drama-studio-theme', 'unexpected')
        const state = setup(true)
        expect(state.preference.value).toBe('system')
        expect(state.isDark.value).toBe(true)
    })

    it('禁用存储仍能切换当前会话的主题', async () => {
        vi.spyOn(Storage.prototype, 'getItem').mockImplementation(() => {
            throw new Error('storage blocked')
        })
        vi.spyOn(Storage.prototype, 'setItem').mockImplementation(() => {
            throw new Error('storage blocked')
        })
        const state = setup()
        state.preference.value = 'dark'
        await nextTick()
        expect(document.documentElement.dataset.theme).toBe('dark')
    })
})