import { computed } from 'vue'
import { MutationTypes, useStore } from '@/store'
import { createRandomCode } from '@/utils/common'
import { getImageSize } from '@/utils/image'
import { VIEWPORT_SIZE } from '@/configs/canvas'
import { PPTLineElement, ChartType, PPTElement, TableCell, TableCellStyle, PPTShapeElement } from '@/types/slides'
import { ShapePoolItem } from '@/configs/shapes'
import { LinePoolItem } from '@/configs/lines'
import useHistorySnapshot from '@/hooks/useHistorySnapshot'

interface CommonElementPosition {
  top: number;
  left: number;
  width: number;
  height: number;
}

interface LineElementPosition {
  top: number;
  left: number;
  start: [number, number];
  end: [number, number];
}

export default () => {
  const store = useStore()
  const themeColor = computed(() => store.state.theme.themeColor)
  const fontColor = computed(() => store.state.theme.fontColor)
  const fontName = computed(() => store.state.theme.fontName)
  const viewportRatio = computed(() => store.state.viewportRatio)
  const creatingElement = computed(() => store.state.creatingElement)

  const { addHistorySnapshot } = useHistorySnapshot()

  // 创建（插入）一个元素并将其设置为被选中元素
  const createElement = (element: PPTElement) => {
    store.commit(MutationTypes.ADD_ELEMENT, element)
    store.commit(MutationTypes.SET_ACTIVE_ELEMENT_ID_LIST, [element.id])

    if (creatingElement.value) store.commit(MutationTypes.SET_CREATING_ELEMENT, null)
    setTimeout(() => {
      store.commit(MutationTypes.SET_EDITORAREA_FOCUS, true)
    }, 0)
    addHistorySnapshot()
  }

  /**
   * 创建图片元素
   * @param src 图片地址
   */
  const createImageElement = (src: string) => {
    getImageSize(src).then(({ width, height }) => {
      const scale = height / width
  
      if (scale < viewportRatio.value && width > VIEWPORT_SIZE) {
        width = VIEWPORT_SIZE
        height = width * scale
      }
      else if (height > VIEWPORT_SIZE * viewportRatio.value) {
        height = VIEWPORT_SIZE * viewportRatio.value
        width = height / scale
      }

      createElement({
        type: 'image',
        id: createRandomCode(),
        src,
        width,
        height,
        left: (VIEWPORT_SIZE - width) / 2,
        top: (VIEWPORT_SIZE * viewportRatio.value - height) / 2,
        fixedRatio: true,
        rotate: 0,
      })
    })
  }
  
  /**
   * 创建图表元素
   * @param chartType 图表类型
   */
  const createChartElement = (chartType: ChartType) => {
    createElement({
      type: 'chart',
      id: createRandomCode(),
      chartType,
      left: 300,
      top: 81.25,
      width: 400,
      height: 400,
      themeColor: themeColor.value,
      gridColor: fontColor.value,
      data: {
        labels: ['类别1', '类别2', '类别3', '类别4', '类别5'],
        series: [
          [12, 19, 5, 2, 18],
        ],
      },
    })
  }
  
  /**
   * 创建表格元素
   * @param row 行数
   * @param col 列数
   */
  const createTableElement = (row: number, col: number) => {
    const style: TableCellStyle = {
      fontname: fontName.value,
      color: fontColor.value,
    }
    const data: TableCell[][] = []
    for (let i = 0; i < row; i++) {
      const rowCells: TableCell[] = []
      for (let j = 0; j < col; j++) {
        rowCells.push({ id: createRandomCode(), colspan: 1, rowspan: 1, text: '', style })
      }
      data.push(rowCells)
    }

    const DEFAULT_CELL_WIDTH = 100
    const DEFAULT_CELL_HEIGHT = 36

    const colWidths: number[] = new Array(col).fill(1 / col)

    const width = col * DEFAULT_CELL_WIDTH
    const height = row * DEFAULT_CELL_HEIGHT

    createElement({
      type: 'table',
      id: createRandomCode(),
      width,
      height,
      colWidths,
      data,
      left: (VIEWPORT_SIZE - width) / 2,
      top: (VIEWPORT_SIZE * viewportRatio.value - height) / 2,
      outline: {
        width: 2,
        style: 'solid',
        color: '#eeece1',
      },
      theme: {
        color: themeColor.value,
        rowHeader: true,
        rowFooter: false,
        colHeader: false,
        colFooter: false,
      },
    })
  }
  
  /**
   * 创建文本元素
   * @param position 位置大小信息
   * @param content 文本内容
   */
  const createTextElement = (position: CommonElementPosition, content = '请输入内容') => {
    const { left, top, width, height } = position
    createElement({
      type: 'text',
      id: createRandomCode(),
      left, 
      top, 
      width, 
      height,
      content,
      rotate: 0,
      defaultFontName: fontName.value,
      defaultColor: fontColor.value,
    })
  }
  
  /**
   * 创建形状元素
   * @param position 位置大小信息
   * @param data 形状路径信息
   */
  const createShapeElement = (position: CommonElementPosition, data: ShapePoolItem) => {
    const { left, top, width, height } = position
    const newElement: PPTShapeElement = {
      type: 'shape',
      id: createRandomCode(),
      left, 
      top, 
      width, 
      height,
      viewBox: data.viewBox,
      path: data.path,
      fill: themeColor.value,
      fixedRatio: false,
      rotate: 0,
    }
    if (data.special) newElement.special = true
    createElement(newElement)
  }
  
  /**
   * 创建线条元素
   * @param position 位置大小信息
   * @param data 线条的路径和样式
   */
  const createLineElement = (position: LineElementPosition, data: LinePoolItem) => {
    const { left, top, start, end } = position

    const newElement: PPTLineElement = {
      type: 'line',
      id: createRandomCode(),
      left, 
      top, 
      start,
      end,
      points: data.points,
      color: themeColor.value,
      style: data.style,
      width: 2,
    }
    if (data.isBroken) newElement.broken = [(start[0] + end[0]) / 2, (start[1] + end[1]) / 2]
    if (data.isCurve) newElement.curve = [(start[0] + end[0]) / 2, (start[1] + end[1]) / 2]
    createElement(newElement)
  }

  return {
    createImageElement,
    createChartElement,
    createTableElement,
    createTextElement,
    createShapeElement,
    createLineElement,
  }
}