// Copyright (c) 2013 Adobe Systems Incorporated. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
import eve from './eve.js'
import { Snap } from './svg.js'
import { is } from './utils.js'
import { SEPARATOR } from './lib/constants.js'
import { parseColor } from './lib/color.js'
import { Matrix } from './matrix.js'

let names = {},
  reUnit = /[%a-z]+$/i,
  Str = String
names.stroke = names.fill = 'colour'
function getEmpty(item) {
  let l = item[0]
  switch (l.toLowerCase()) {
    case 't':
      return [l, 0, 0]
    case 'm':
      return [l, 1, 0, 0, 1, 0, 0]
    case 'r':
      if (item.length == 4) {
        return [l, 0, item[2], item[3]]
      } else {
        return [l, 0]
      }
    case 's':
      if (item.length == 5) {
        return [l, 1, 1, item[3], item[4]]
      } else if (item.length == 3) {
        return [l, 1, 1]
      } else {
        return [l, 1]
      }
  }
}
function equaliseTransform(t1, t2, getBBox) {
  t1 = t1 || new Matrix()
  t2 = t2 || new Matrix()
  t1 = Snap.parseTransformString(t1.toTransformString()) || []
  t2 = Snap.parseTransformString(t2.toTransformString()) || []
  let maxlength = Math.max(t1.length, t2.length),
    from = [],
    to = [],
    i = 0,
    j,
    jj,
    tt1,
    tt2
  for (; i < maxlength; i++) {
    tt1 = t1[i] || getEmpty(t2[i])
    tt2 = t2[i] || getEmpty(tt1)
    if (
      tt1[0] != tt2[0] ||
      (tt1[0].toLowerCase() == 'r' && (tt1[2] != tt2[2] || tt1[3] != tt2[3])) ||
      (tt1[0].toLowerCase() == 's' && (tt1[3] != tt2[3] || tt1[4] != tt2[4]))
    ) {
      t1 = Snap._.transform2matrix(t1, getBBox())
      t2 = Snap._.transform2matrix(t2, getBBox())
      from = [['m', t1.a, t1.b, t1.c, t1.d, t1.e, t1.f]]
      to = [['m', t2.a, t2.b, t2.c, t2.d, t2.e, t2.f]]
      break
    }
    from[i] = []
    to[i] = []
    for (j = 0, jj = Math.max(tt1.length, tt2.length); j < jj; j++) {
      j in tt1 && (from[i][j] = tt1[j])
      j in tt2 && (to[i][j] = tt2[j])
    }
  }
  return {
    from: path2array(from),
    to: path2array(to),
    f: getPath(from)
  }
}
function getNumber(val) {
  return val
}
function getUnit(unit) {
  return function (val) {
    return +val.toFixed(3) + unit
  }
}
function getViewBox(val) {
  return val.join(' ')
}
function getColour(clr) {
  return Snap.rgb(clr[0], clr[1], clr[2], clr[3])
}
function getPath(path) {
  let k = 0,
    i,
    ii,
    j,
    jj,
    out,
    a,
    b = []
  for (i = 0, ii = path.length; i < ii; i++) {
    out = '['
    a = ['"' + path[i][0] + '"']
    for (j = 1, jj = path[i].length; j < jj; j++) {
      a[j] = 'val[' + k++ + ']'
    }
    out += a + ']'
    b[i] = out
  }
  return Function('val', 'return Snap.path.toString.call([' + b + '])')
}
function path2array(path) {
  let out = []
  for (let i = 0, ii = path.length; i < ii; i++) {
    for (let j = 1, jj = path[i].length; j < jj; j++) {
      out.push(path[i][j])
    }
  }
  return out
}
function isNumeric(obj) {
  return isFinite(obj)
}
function arrayEqual(arr1, arr2) {
  if (!is(arr1, 'array') || !is(arr2, 'array')) {
    return false
  }
  return arr1.toString() == arr2.toString()
}

eve.on('snap.util.equal', function (name, b) {
  let A,
    B,
    a = Str(this.attr(name) || ''),
    el = this
  if (names[name] == 'colour') {
    A = parseColor(a)
    B = parseColor(b)
    return {
      from: [A.r, A.g, A.b, A.opacity],
      to: [B.r, B.g, B.b, B.opacity],
      f: getColour
    }
  }
  if (name == 'viewBox') {
    A = this.attr(name).vb.split(' ').map(Number)
    B = b.split(' ').map(Number)
    return {
      from: A,
      to: B,
      f: getViewBox
    }
  }
  if (
    name == 'transform' ||
    name == 'gradientTransform' ||
    name == 'patternTransform'
  ) {
    if (typeof b == 'string') {
      b = Str(b).replace(/\.{3}|\u2026/g, a)
    }
    a = this.matrix
    if (!Snap._.rgTransform.test(b)) {
      b = Snap._.transform2matrix(Snap._.svgTransform2string(b), this.getBBox())
    } else {
      b = Snap._.transform2matrix(b, this.getBBox())
    }
    return equaliseTransform(a, b, function () {
      return el.getBBox(1)
    })
  }
  if (name == 'd' || name == 'path') {
    A = Snap.path.toCubic(a, b)
    return {
      from: path2array(A[0]),
      to: path2array(A[1]),
      f: getPath(A[0])
    }
  }
  if (name == 'points') {
    A = Str(a).split(SEPARATOR)
    B = Str(b).split(SEPARATOR)
    return {
      from: A,
      to: B,
      f: function (val) {
        return val
      }
    }
  }
  if (isNumeric(a) && isNumeric(b)) {
    return {
      from: parseFloat(a),
      to: parseFloat(b),
      f: getNumber
    }
  }
  let aUnit = a.match(reUnit),
    bUnit = Str(b).match(reUnit)
  if (aUnit && arrayEqual(aUnit, bUnit)) {
    return {
      from: parseFloat(a),
      to: parseFloat(b),
      f: getUnit(aUnit)
    }
  } else {
    return {
      from: this.asPX(name),
      to: this.asPX(name, b),
      f: getNumber
    }
  }
})