var util = require('../../utils/util')

Component({
  properties: {
    duration: { type: Number, value: 60 },
    remaining: { type: Number, value: 60 },
    size: { type: Number, value: 280 },
    ringWidth: { type: Number, value: 14 },
    status: { type: String, value: 'idle' },
    primaryColor: { type: String, value: '#FF6B35' },
    primaryLightColor: { type: String, value: '#FF8C5A' }
  },

  data: {
    displayTime: '00:00',
    statusText: '准备开始'
  },

  observers: {
    'remaining, status, duration, size, ringWidth, primaryColor': function () {
      var texts = { idle: '准备开始', running: '坚持住', paused: '已暂停', completed: '完成!' }
      this.setData({
        displayTime: util.formatTime(this.data.remaining),
        statusText: texts[this.data.status] || ''
      })
      this._draw()
    }
  },

  lifetimes: {
    ready: function () {
      var self = this
      var query = this.createSelectorQuery()
      query.select('#ringCanvas')
        .fields({ node: true, size: true })
        .exec(function (res) {
          if (!res || !res[0] || !res[0].node) return
          var canvas = res[0].node
          var dpr = wx.getSystemInfoSync().pixelRatio || 2
          var displaySize = self.data.size
          canvas.width = displaySize * dpr
          canvas.height = displaySize * dpr
          self._ctx = canvas.getContext('2d')
          self._dpr = dpr
          self._draw()
        })
    }
  },

  methods: {
    _draw: function () {
      var ctx = this._ctx
      if (!ctx) return

      var size = this.data.size
      var dpr = this._dpr
      var ringWidth = this.data.ringWidth
      var duration = this.data.duration
      var remaining = this.data.remaining
      var primaryColor = this.data.primaryColor

      var w = size * dpr
      var h = size * dpr
      ctx.clearRect(0, 0, w, h)

      var cx = w / 2
      var cy = h / 2
      var radius = (size - ringWidth) / 2 * dpr
      var lw = ringWidth * dpr

      // track ring
      ctx.beginPath()
      ctx.arc(cx, cy, radius, 0, Math.PI * 2)
      ctx.strokeStyle = '#EEEEEE'
      ctx.lineWidth = lw
      ctx.lineCap = 'round'
      ctx.stroke()

      // progress arc (clockwise from 12 o'clock, represents remaining time)
      var ratio = duration > 0 ? Math.max(0, Math.min(1, remaining / duration)) : 0
      if (ratio > 0.001) {
        var startAngle = -Math.PI / 2
        var endAngle = startAngle + ratio * Math.PI * 2
        ctx.beginPath()
        ctx.arc(cx, cy, radius, startAngle, endAngle)
        ctx.strokeStyle = primaryColor
        ctx.lineWidth = lw
        ctx.lineCap = 'round'
        ctx.stroke()
      }
    }
  }
})