import type { Layer } from '@/components/editor/canvas/types'
import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
import { useComponentTemplates } from '@/composables/useComponentTemplates'

const RE_TPL_PREFIX = /^tpl_/
const RE_DEFAULT_NAME = /^模板 \d+$/

// 模拟 @vueuse/core 的 useLocalStorage
// useComponentTemplates 通过 useLocalStorage 管理持久化，
// 测试中用 ref 替代以隔离 localStorage 副作用
vi.mock('@vueuse/core', async () => {
  const { ref } = await import('vue')
  return {
    useLocalStorage: (_key: string, defaultValue: any) => ref(defaultValue),
  }
})

function createMockLayer(overrides: Partial<Layer> = {}): Layer {
  return {
    id: `layer_${Math.random().toString(36).slice(2, 6)}`,
    type: 'rect',
    x: 0,
    y: 0,
    width: 100,
    height: 50,
    ...overrides,
  }
}

describe('useComponentTemplates', () => {
  let tpl: ReturnType<typeof useComponentTemplates>

  beforeEach(() => {
    vi.useFakeTimers()
    tpl = useComponentTemplates()
  })

  afterEach(() => {
    vi.useRealTimers()
  })

  // ──── saveTemplate() ────

  describe('saveTemplate() 保存模板', () => {
    it('应保存模板并返回模板对象', () => {
      const layers = [createMockLayer()]
      const result = tpl.saveTemplate('测试模板', layers)

      expect(result).not.toBeNull()
      expect(result!.name).toBe('测试模板')
      expect(result!.layers).toHaveLength(1)
      expect(result!.id).toMatch(RE_TPL_PREFIX)
      expect(result!.createdAt).toBeTypeOf('number')
    })

    it('空图层数组时应返回 null', () => {
      const result = tpl.saveTemplate('空模板', [])

      expect(result).toBeNull()
    })

    it('名称为空字符串时应使用默认名称', () => {
      const layers = [createMockLayer()]
      const result = tpl.saveTemplate('', layers)

      expect(result).not.toBeNull()
      expect(result!.name).toMatch(RE_DEFAULT_NAME)
    })

    it('名称含前后空格时应自动 trim', () => {
      const layers = [createMockLayer()]
      const result = tpl.saveTemplate('  模板名称  ', layers)

      expect(result!.name).toBe('模板名称')
    })

    it('应深拷贝图层数据，修改原图层不影响模板', () => {
      const layer = createMockLayer({ x: 10 })
      const layers = [layer]
      const result = tpl.saveTemplate('深拷贝测试', layers)

      // 修改原图层
      layer.x = 999

      expect(result!.layers[0].x).toBe(10)
    })

    it('多次保存应生成不同的 id', () => {
      const layers = [createMockLayer()]

      vi.setSystemTime(new Date('2026-01-01T00:00:00Z'))
      const t1 = tpl.saveTemplate('模板1', layers)

      vi.setSystemTime(new Date('2026-01-01T00:00:01Z'))
      const t2 = tpl.saveTemplate('模板2', layers)

      expect(t1!.id).not.toBe(t2!.id)
    })
  })

  // ──── templates（sortedTemplates）────

  describe('templates 排序', () => {
    it('空状态返回空数组', () => {
      expect(tpl.templates.value).toEqual([])
    })

    it('应按 createdAt 降序排列（新模板在前）', () => {
      const layers = [createMockLayer()]

      vi.setSystemTime(new Date('2026-01-01T00:00:00Z'))
      tpl.saveTemplate('旧模板', layers)

      vi.setSystemTime(new Date('2026-01-02T00:00:00Z'))
      tpl.saveTemplate('新模板', layers)

      expect(tpl.templates.value).toHaveLength(2)
      expect(tpl.templates.value[0].name).toBe('新模板')
      expect(tpl.templates.value[1].name).toBe('旧模板')
    })
  })

  // ──── getTemplate() ────

  describe('getTemplate() 按 id 获取模板', () => {
    it('存在时返回模板对象', () => {
      const layers = [createMockLayer()]
      const saved = tpl.saveTemplate('查找测试', layers)!

      const found = tpl.getTemplate(saved.id)

      expect(found).not.toBeNull()
      expect(found!.id).toBe(saved.id)
      expect(found!.name).toBe('查找测试')
    })

    it('不存在时返回 null', () => {
      expect(tpl.getTemplate('nonexistent_id')).toBeNull()
    })
  })

  // ──── removeTemplate() ────

  describe('removeTemplate() 删除模板', () => {
    it('应按 id 删除指定模板', () => {
      const layers = [createMockLayer()]
      const t1 = tpl.saveTemplate('模板1', layers)!
      const t2 = tpl.saveTemplate('模板2', layers)!

      tpl.removeTemplate(t1.id)

      expect(tpl.templates.value).toHaveLength(1)
      expect(tpl.templates.value[0].id).toBe(t2.id)
    })

    it('删除不存在的 id 不应报错', () => {
      const layers = [createMockLayer()]
      tpl.saveTemplate('模板', layers)

      expect(() => tpl.removeTemplate('nonexistent')).not.toThrow()
      expect(tpl.templates.value).toHaveLength(1)
    })
  })

  // ──── renameTemplate() ────

  describe('renameTemplate() 重命名模板', () => {
    it('应更新指定模板的名称', () => {
      const layers = [createMockLayer()]
      const saved = tpl.saveTemplate('原始名称', layers)!

      tpl.renameTemplate(saved.id, '新名称')

      const updated = tpl.getTemplate(saved.id)
      expect(updated!.name).toBe('新名称')
    })

    it('名称含空格时应自动 trim', () => {
      const layers = [createMockLayer()]
      const saved = tpl.saveTemplate('原始', layers)!

      tpl.renameTemplate(saved.id, '  修改后  ')

      expect(tpl.getTemplate(saved.id)!.name).toBe('修改后')
    })

    it('重命名不存在的 id 不应报错', () => {
      expect(() => tpl.renameTemplate('nonexistent', '新名称')).not.toThrow()
    })

    it('重命名不应影响其他字段', () => {
      const layers = [createMockLayer({ x: 42 })]
      const saved = tpl.saveTemplate('原始', layers)!
      const originalCreatedAt = saved.createdAt

      tpl.renameTemplate(saved.id, '新名称')

      const updated = tpl.getTemplate(saved.id)!
      expect(updated.createdAt).toBe(originalCreatedAt)
      expect(updated.layers[0].x).toBe(42)
    })
  })

  // ──── 边界情况 ────

  describe('边界情况', () => {
    it('保存含多个图层的模板', () => {
      const layers = [
        createMockLayer({ x: 0, y: 0 }),
        createMockLayer({ x: 100, y: 100 }),
        createMockLayer({ x: 200, y: 200 }),
      ]
      const result = tpl.saveTemplate('多图层模板', layers)

      expect(result!.layers).toHaveLength(3)
    })

    it('图层含嵌套 config 对象时应深拷贝', () => {
      const config = { fill: 'red', nested: { value: 1 } }
      const layer = createMockLayer({ config })
      const result = tpl.saveTemplate('嵌套配置', [layer])

      // 修改原始 config
      config.nested.value = 999

      expect(result!.layers[0].config!.nested.value).toBe(1)
    })
  })
})