/**
 * {color组件}
 * @author chensbox <chensbox@foxmail.com>
 * @date 2023/03/20 15:17:25
 */

import {
  css,
  html,
  bind,
  unbind,
  Component,
  outsideClick,
  clearOutsideClick,
  nextTick,
  offset,
  styleMap
} from 'wkit'

const EV_OPTION = { once: true }
const DOC = document
const ROOT = document.documentElement

// H: 色相, S: 饱和度, B/V: 亮度
export function hsb2rgb(hsb) {
  var h = hsb.h
  var s = Math.round((hsb.s * 255) / 100)
  var v = Math.round((hsb.b * 255) / 100)
  var r = 0
  var g = 0
  var b = 0

  if (s === 0) {
    r = g = b = v
  } else {
    var t1 = v
    var t2 = ((255 - s) * v) / 255
    var t3 = ((t1 - t2) * (h % 60)) / 60

    //
    if (h === 360) {
      h = 0
    }

    if (h < 60) {
      r = t1
      g = t2 + t3
      b = t2
    } else if (h < 120) {
      r = t1 - t3
      g = t1
      b = t2
    } else if (h < 180) {
      r = t2
      g = t1
      b = t2 + t3
    } else if (h < 240) {
      r = t2
      g = t1 - t3
      b = t1
    } else if (h < 300) {
      r = t2 + t3
      g = t2
      b = t1
    } else if (h < 360) {
      r = t1
      g = t2
      b = t1 - t3
    }
  }
  r = Math.round(r)
  g = Math.round(g)
  b = Math.round(b)

  return { r, g, b }
}

export function rgb2hex({ r, g, b }) {
  return [r, g, b].map(it => it.toString(16).padStart(2, '0')).join('')
}

export function hex2rgb(hex) {
  var r, g, b

  hex = hex.replace(/^#/, '').split('')

  if (hex.length === 3) {
    r = parseInt(hex[0] + hex[0], 16)
    g = parseInt(hex[1] + hex[1], 16)
    b = parseInt(hex[2] + hex[2], 16)
  } else {
    r = parseInt(hex[0] + hex[1], 16)
    g = parseInt(hex[2] + hex[3], 16)
    b = parseInt(hex[4] + hex[5], 16)
  }

  return { r, g, b }
}

export function rgb2hsb({ r, g, b }) {
  var hsb = { h: 0, s: 0, b: 0 }
  var max = Math.max(r, g, b)
  var min = Math.min(r, g, b)
  var delta = max - min

  hsb.b = max
  hsb.s = max === 0 ? 0 : (delta * 255) / max

  if (hsb.s === 0) {
    hsb.h = -1
  } else {
    if (r === max) {
      hsb.h = (g - b) / delta
    } else if (g === max) {
      hsb.h = 2 + (b - r) / delta
    } else {
      hsb.h = 4 + (r - g) / delta
    }
  }
  hsb.h *= 60

  if (hsb.h < 0) {
    hsb.h += 360
  }

  hsb.s *= 100 / 255
  hsb.b *= 100 / 255

  return hsb
}

export function hex2hsb(hex) {
  return rgb2hsb(hex2rgb(hex))
}

class Color extends Component {
  static props = {
    value: {
      type: String,
      default: '',
      observer(val) {
        if (this.#show) {
          this.#calc(val)
        }
      }
    },
    disabled: false
  }

  static styles = [
    css`
      :host {
        display: inline-flex;
      }
      .container {
        position: relative;
        width: 32px;
        height: 32px;
      }
      .alpha-bg {
        background: linear-gradient(
            45deg,
            var(--color-grey-1) 25%,
            transparent 25%,
            transparent 75%,
            var(--color-grey-1) 75%,
            var(--color-grey-1)
          ),
          linear-gradient(
            45deg,
            var(--color-grey-1) 25%,
            transparent 25%,
            transparent 75%,
            var(--color-grey-1) 75%,
            var(--color-grey-1)
          );
        background-size: 12px 12px;
        background-position: 0 0, 6px 6px;
      }
    `,
    // 预览
    css`
      .preview {
        display: flex;
        width: 100%;
        height: 100%;
        border: 1px solid var(--color-grey-2);
        border-radius: 3px;
        cursor: pointer;
        transition: box-shadow 0.15s linear;

        span {
          width: 100%;
          height: 100%;
          border: 3px solid #fff;
          border-radius: 3px;
          background: var(--value);
          outline: none;
        }

        &:focus-within {
          box-shadow: 0 0 0 2px var(--color-plain-a);
        }
      }
    `,
    // .color-panel
    css`
      .color-panel {
        display: var(--show, none);
        position: absolute;
        z-index: 1;
        left: 0;
        top: 38px;
        width: 310px;
        padding: 5px;
        background: #fff;
        box-shadow: 0 0 20px rgba(0, 0, 0, 0.15);
      }
      .dashboard {
        display: flex;
        justify-content: space-between;

        .scene {
          overflow: hidden;
          position: relative;
          width: 280px;
          height: 180px;
          background: linear-gradient(180deg, transparent, #000),
            linear-gradient(90deg, #fff, transparent), var(--scene);

          .thumb {
            position: absolute;
            z-index: 1;
            left: var(--x);
            top: var(--y);
            width: 0;
            height: 0;

            &::after {
              display: block;
              width: 10px;
              height: 10px;
              border: 1px solid #fff;
              border-radius: 50%;
              background: rgba(32, 32, 32, 0.3);
              transform: translate(-5px, -5px);
              content: '';
            }
          }
        }

        .pool {
          overflow: hidden;
          position: relative;
          width: 12px;
          height: 180px;
          background: linear-gradient(
            to bottom,
            #f00 0,
            #ff0 17%,
            #0f0 33%,
            #0ff 50%,
            #00f 67%,
            #f0f 83%,
            #f00
          );

          .thumb {
            position: absolute;
            left: 0;
            top: var(--ht);
            width: 12px;
            height: 0;

            &::after {
              display: block;
              width: 12px;
              height: 12px;
              border-radius: 50%;
              background: #fff;
              box-shadow: 0 0 3px rgba(0, 0, 0, 0.5);
              transform: translateY(-6px);
              content: '';
            }
          }
        }
      }
      .alpha-box {
        overflow: hidden;
        position: relative;
        width: 100%;
        height: 12px;
        margin: 12px 0;

        .bar {
          position: absolute;
          left: 0;
          top: 0;
          width: 100%;
          height: 12px;
          background: linear-gradient(90deg, transparent, var(--alpha));
        }

        .thumb {
          position: absolute;
          left: var(--at);
          top: 0;
          width: 0;
          height: 12px;

          &::after {
            display: block;
            width: 12px;
            height: 12px;
            border-radius: 50%;
            background: #fff;
            box-shadow: 0 0 3px rgba(0, 0, 0, 0.5);
            transform: translateX(-6px);
            content: '';
          }
        }

        .alpha {
          position: relative;
          display: block;
          width: 100%;
          height: 12px;
          opacity: 0;
        }
      }
    `,
    css`
      .input-box {
        display: flex;
        justify-content: space-between;
        align-items: center;
        padding: 6px 0;

        .input {
          width: 200px;
          height: 24px;
          padding: 0 6px;
          line-height: 22px;
          font: inherit;
          font-size: 12px;
          border: 2px solid var(--color-plain-2);
          border-radius: 4px;
          outline: none;
          color: var(--color-dark-1);
          transition: box-shadow 0.15s linear;

          &::placeholder {
            color: var(--color-grey-1);
          }
          &:focus {
            box-shadow: 0 0 0 2px var(--color-plain-a);
          }
        }

        .clear,
        .submit {
          font-size: 12px;
          cursor: pointer;
          user-select: none;
        }

        .clear {
          color: var(--color-grey-3);
        }

        .submit {
          padding: 2px 6px;
          border-radius: 2px;
          color: var(--color-plain-1);
          background: var(--color-teal-2);
          outline: none;
          transition: box-shadow 0.15s linear, background 0.15s linear;

          &:hover {
            background: var(--color-teal-1);
          }

          &:focus {
            box-shadow: 0 0 0 2px var(--color-teal-a);
          }
        }
      }
    `,

    css`
      :host([disabled]) {
        opacity: 0.6;

        .preview {
          cursor: not-allowed;

          &:focus-within {
            box-shadow: unset;
          }
        }
      }
    `
  ]

  #show = false

  // 临时的value, 组件内的操作, 修改的是这个值, 避免直接修改value触发太多的计算
  #value = ''
  #x = 0 // 场景触点的X坐标
  #y = 0 // 场景触点的Y坐标
  #ht = 0 // 颜色池的触点坐标
  #at = 100 // 透明度条的触点坐标
  #sceneBg = '#ff0000'
  #alphaBg = '#ff0000'

  #cache = {
    hsb: { h: 0, s: 100, b: 100 },
    rgba: { r: 255, g: 0, b: 0, a: 100 }
  }

  #calc(val) {
    var isHex
    var rgb

    val = val.toLowerCase()

    if (!val) {
      return
    }

    isHex = /^#[0-9a-f]{3,6}$/.test(val)

    if (isHex) {
      Object.assign(this.#cache.rgba, hex2rgb(val), { a: 100 })
    } else {
      var res = val.match(/rgba?\((\d+),\s*?(\d+),\s*?(\d+)[,\s]*?([\d\.]+)?\)/)
      if (res) {
        this.#cache.rgba = { r: +res[1], g: +res[2], b: +res[3], a: 100 }
        if (res[4] !== undefined) {
          this.#cache.rgba.a = ~~(res[4] * 100)
        }
      } else {
        return
      }
    }

    this.#cache.hsb = rgb2hsb(this.#cache.rgba)
  }

  toggleColorPanel() {
    if (this.disabled) {
      return
    }
    this.#show = true
    this.#updateView()
  }

  // 透明度变化
  #changeAlpha(ev) {
    let a = +ev.target.value
    let { r, g, b } = this.#cache.rgba

    this.#cache.rgba.a = a
    this.#updateView()
  }
  // 色彩池变化
  #changeHue(h) {
    h = h < 0 ? 0 : h > 360 ? 360 : h
    let { s, b } = this.#cache.hsb
    let rgba = this.#cache.rgba
    let hsb = { h, s, b }

    Object.assign(rgba, hsb2rgb(hsb))

    this.#cache.hsb = hsb
    this.#cache.rgba = rgba

    this.#updateView()
  }
  //
  #changeColor(x, y) {
    let { hsb, rgba } = this.#cache
    hsb.s = ~~((100 * x) / 280)
    hsb.b = ~~((100 * (180 - y)) / 180)
    Object.assign(rgba, hsb2rgb(hsb))

    this.#cache.hsb = hsb
    this.#cache.rgba = rgba
    this.#updateView()
  }

  #sceneMousedown(ev) {
    let { x, y } = ev
    let { left, top } = offset(ev.currentTarget)
    let { scrollLeft, scrollTop } = ROOT
    let _x = left - scrollLeft
    let _y = top - scrollTop

    this.#changeColor(x - _x, y - _y)

    let callback = bind(DOC, 'mousemove', ({ x, y }) => {
      x -= _x
      y -= _y

      x = x < 0 ? 0 : x > 280 ? 280 : x
      y = y < 0 ? 0 : y > 180 ? 180 : y

      this.#changeColor(x, y)
    })
    bind(DOC, 'mouseup', _ => unbind(DOC, 'mousemove', callback), EV_OPTION)
  }

  #poolMousedown(ev) {
    let { y } = ev
    let { top } = offset(ev.currentTarget)
    let { scrollTop } = ROOT
    let { clientHeight: h } = ev.currentTarget
    let _y = top - scrollTop

    y -= _y

    this.#changeHue(~~((y / h) * 360))

    let callback = bind(DOC, 'mousemove', ({ y }) => {
      y -= _y
      this.#changeHue(~~((y / h) * 360))
    })
    bind(DOC, 'mouseup', _ => unbind(DOC, 'mousemove', callback), EV_OPTION)
  }

  #close(clear) {
    if (this.#show) {
      this.#show = false
      this.#calc(this.value)
      this.#updateView()
    }
  }

  #submit() {
    this.value = this.#value
    this.#close()
    this.$emit('change', { data: this.#value })
  }

  #updateView() {
    var { hsb, rgba } = this.#cache
    var sceneBg, color, alphaBg
    var x, y

    x = Math.ceil((hsb.s * 280) / 100)
    y = 180 - Math.ceil((hsb.b * 180) / 100)

    sceneBg = '#' + rgb2hex(hsb2rgb({ h: hsb.h, s: 100, b: 100 }))
    alphaBg = '#' + rgb2hex(rgba)

    if (rgba.a < 100) {
      color = `rgba(${rgba.r}, ${rgba.g}, ${rgba.b}, ${rgba.a / 100})`
    } else {
      color = alphaBg
    }

    this.#sceneBg = sceneBg
    this.#alphaBg = alphaBg
    this.#value = color
    this.#x = x
    this.#y = y
    this.#ht = hsb.h / 2
    this.#at = rgba.a
    this.$requestUpdate()
  }

  mounted() {
    // 更新一次视图
    this.#updateView()

    // 点击外部区别时,还原之前的颜色值
    this._outsideFn = outsideClick(this, ev => {
      this.#close()
    })
  }

  unmounted() {
    clearOutsideClick(this._outsideFn)
  }

  render() {
    let styles = styleMap({
      '--show': this.#show ? 'block' : 'none',
      '--value': this.#value,
      '--scene': this.#sceneBg,
      '--x': this.#x + 'px',
      '--y': this.#y + 'px',
      '--ht': this.#ht + 'px',
      '--at': this.#at + '%',
      '--alpha': this.#alphaBg
    })

    return html`
      <main class="container" style=${styles}>
        <section class="preview alpha-bg" @click=${this.toggleColorPanel}>
          <span tabindex=${this.disabled ? -1 : 0}></span>
        </section>

        <div class="color-panel">
          <section class="dashboard">
            <div class="scene" @mousedown.prevent=${this.#sceneMousedown}>
              <i class="thumb"></i>
            </div>
            <div class="pool" @mousedown.prevent=${this.#poolMousedown}>
              <i class="thumb"></i>
            </div>
          </section>

          <section class="alpha-box alpha-bg">
            <div class="bar"></div>
            <i class="thumb"></i>
            <input
              class="alpha"
              max="100"
              min="0"
              step="1"
              type="range"
              @input=${this.#changeAlpha}
            />
          </section>

          <section class="input-box">
            <input class="input" :value=${this.#value} maxlength="25" />
            <a class="clear" @click=${_ => this.#close(true)}>清除</a>
            <a tabindex="0" class="submit" @click=${this.#submit}>确定</a>
          </section>
        </div>
      </main>
    `
  }
}

Color.reg('color')