/**
 * terminal.js - term.js terminal element for blessed
 * Copyright (c) 2013-2015, Christopher Jeffrey and contributors (MIT License).
 * https://github.com/chjj/blessed
 */

/**
 * Modules
 */

const nextTick = global.setImmediate || process.nextTick.bind(process)

const Node = require('./node')
const Box = require('./box')

/**
 * Terminal
 */

function Terminal(options) {
  if (!(this instanceof Node)) {
    return new Terminal(options)
  }

  options = options || {}
  options.scrollable = false

  Box.call(this, options)

  // XXX Workaround for all motion
  if (this.screen.program.tmux && this.screen.program.tmuxVersion >= 2) {
    this.screen.program.enableMouse()
  }

  this.handler = options.handler
  this.shell = options.shell || process.env.SHELL || 'sh'
  this.args = options.args || []

  this.cursor = this.options.cursor
  this.cursorBlink = this.options.cursorBlink
  this.screenKeys = this.options.screenKeys

  this.style = this.style || {}
  this.style.bg = this.style.bg || 'default'
  this.style.fg = this.style.fg || 'default'

  this.termName =
    options.terminal || options.term || process.env.TERM || 'xterm'

  this.bootstrap()
}

Object.setPrototypeOf(Terminal.prototype, Box.prototype)

Terminal.prototype.type = 'terminal'

Terminal.prototype.bootstrap = function () {
  const self = this

  const element = {
    // window
    get document() {
      return element
    },
    navigator: { userAgent: 'node.js' },

    // document
    get defaultView() {
      return element
    },
    get documentElement() {
      return element
    },
    createElement: function () {
      return element
    },

    // element
    get ownerDocument() {
      return element
    },
    addEventListener: function () {},
    removeEventListener: function () {},
    getElementsByTagName: function () {
      return [element]
    },
    getElementById: function () {
      return element
    },
    parentNode: null,
    offsetParent: null,
    appendChild: function () {},
    removeChild: function () {},
    setAttribute: function () {},
    getAttribute: function () {},
    style: {},
    focus: function () {},
    blur: function () {},
    console: console
  }

  element.parentNode = element
  element.offsetParent = element

  this.term = require('term.js')({
    termName: this.termName,
    cols: this.width - this.iwidth,
    rows: this.height - this.iheight,
    context: element,
    document: element,
    body: element,
    parent: element,
    cursorBlink: this.cursorBlink,
    screenKeys: this.screenKeys
  })

  this.term.refresh = function () {
    self.screen.render()
  }

  this.term.keyDown = function () {}
  this.term.keyPress = function () {}

  this.term.open(element)

  // Emits key sequences in html-land.
  // Technically not necessary here.
  // In reality if we wanted to be neat, we would overwrite the keyDown and
  // keyPress methods with our own node.js-keys->terminal-keys methods, but
  // since all the keys are already coming in as escape sequences, we can just
  // send the input directly to the handler/socket (see below).
  // this.term.on('data', function(data) {
  //   self.handler(data);
  // });

  // Incoming keys and mouse inputs.
  // NOTE: Cannot pass mouse events - coordinates will be off!
  this.screen.program.input.on(
    'data',
    (this._onData = function (data) {
      if (self.screen.focused === self && !self._isMouse(data)) {
        self.handler(data)
      }
    })
  )

  this.onScreenEvent('mouse', function (data) {
    if (self.screen.focused !== self) {
      return
    }

    if (data.x < self.aleft + self.ileft) {
      return
    }
    if (data.y < self.atop + self.itop) {
      return
    }
    if (data.x > self.aleft - self.ileft + self.width) {
      return
    }
    if (data.y > self.atop - self.itop + self.height) {
      return
    }

    if (
      self.term.x10Mouse ||
      self.term.vt200Mouse ||
      self.term.normalMouse ||
      self.term.mouseEvents ||
      self.term.utfMouse ||
      self.term.sgrMouse ||
      self.term.urxvtMouse
    ) {
    } else {
      return
    }

    let b = data.raw[0],
      x = data.x - self.aleft,
      y = data.y - self.atop,
      s

    if (self.term.urxvtMouse) {
      if (self.screen.program.sgrMouse) {
        b += 32
      }
      s = '\x1b[' + b + ';' + (x + 32) + ';' + (y + 32) + 'M'
    } else if (self.term.sgrMouse) {
      if (!self.screen.program.sgrMouse) {
        b -= 32
      }
      s =
        '\x1b[<' +
        b +
        ';' +
        x +
        ';' +
        y +
        (data.action === 'mousedown' ? 'M' : 'm')
    } else {
      if (self.screen.program.sgrMouse) {
        b += 32
      }
      s =
        '\x1b[M' +
        String.fromCharCode(b) +
        String.fromCharCode(x + 32) +
        String.fromCharCode(y + 32)
    }

    self.handler(s)
  })

  this.on('focus', function () {
    self.term.focus()
  })

  this.on('blur', function () {
    self.term.blur()
  })

  this.term.on('title', function (title) {
    self.title = title
    self.emit('title', title)
  })

  this.term.on('passthrough', function (data) {
    self.screen.program.flush()
    self.screen.program._owrite(data)
  })

  this.on('resize', function () {
    nextTick(function () {
      self.term.resize(self.width - self.iwidth, self.height - self.iheight)
    })
  })

  this.once('render', function () {
    self.term.resize(self.width - self.iwidth, self.height - self.iheight)
  })

  this.on('destroy', function () {
    self.kill()
    self.screen.program.input.removeListener('data', self._onData)
  })

  if (this.handler) {
    return
  }

  this.pty = require('pty.js').fork(this.shell, this.args, {
    name: this.termName,
    cols: this.width - this.iwidth,
    rows: this.height - this.iheight,
    cwd: process.env.HOME,
    env: this.options.env || process.env
  })

  this.on('resize', function () {
    nextTick(function () {
      try {
        self.pty.resize(self.width - self.iwidth, self.height - self.iheight)
      } catch (e) {}
    })
  })

  this.handler = function (data) {
    self.pty.write(data)
    self.screen.render()
  }

  this.pty.on('data', function (data) {
    self.write(data)
    self.screen.render()
  })

  this.pty.on('exit', function (code) {
    self.emit('exit', code || null)
  })

  this.onScreenEvent('keypress', function () {
    self.screen.render()
  })

  this.screen._listenKeys(this)
}

Terminal.prototype.write = function (data) {
  return this.term.write(data)
}

Terminal.prototype.render = function () {
  const ret = this._render()
  if (!ret) {
    return
  }

  this.dattr = this.sattr(this.style)

  let xi = ret.xi + this.ileft,
    xl = ret.xl - this.iright,
    yi = ret.yi + this.itop,
    yl = ret.yl - this.ibottom,
    cursor

  const scrollback = this.term.lines.length - (yl - yi)

  for (let y = Math.max(yi, 0); y < yl; y++) {
    const line = this.screen.lines[y]
    if (!line || !this.term.lines[scrollback + y - yi]) {
      break
    }

    if (
      y === yi + this.term.y &&
      this.term.cursorState &&
      this.screen.focused === this &&
      (this.term.ydisp === this.term.ybase || this.term.selectMode) &&
      !this.term.cursorHidden
    ) {
      cursor = xi + this.term.x
    } else {
      cursor = -1
    }

    for (let x = Math.max(xi, 0); x < xl; x++) {
      if (!line[x] || !this.term.lines[scrollback + y - yi][x - xi]) {
        break
      }

      line[x][0] = this.term.lines[scrollback + y - yi][x - xi][0]

      if (x === cursor) {
        if (this.cursor === 'line') {
          line[x][0] = this.dattr
          line[x][1] = '\u2502'
          continue
        } else if (this.cursor === 'underline') {
          line[x][0] = this.dattr | (2 << 18)
        } else if (this.cursor === 'block' || !this.cursor) {
          line[x][0] = this.dattr | (8 << 18)
        }
      }

      line[x][1] = this.term.lines[scrollback + y - yi][x - xi][1]

      // default foreground = 257
      if (((line[x][0] >> 9) & 0x1ff) === 257) {
        line[x][0] &= ~(0x1ff << 9)
        line[x][0] |= ((this.dattr >> 9) & 0x1ff) << 9
      }

      // default background = 256
      if ((line[x][0] & 0x1ff) === 256) {
        line[x][0] &= ~0x1ff
        line[x][0] |= this.dattr & 0x1ff
      }
    }

    line.dirty = true
  }

  return ret
}

Terminal.prototype._isMouse = function (buf) {
  let s = buf
  if (Buffer.isBuffer(s)) {
    if (s[0] > 127 && s[1] === undefined) {
      s[0] -= 128
      s = '\x1b' + s.toString('utf-8')
    } else {
      s = s.toString('utf-8')
    }
  }
  return (
    (buf[0] === 0x1b && buf[1] === 0x5b && buf[2] === 0x4d) ||
    /^\x1b\[M([\x00\u0020-\uffff]{3})/.test(s) ||
    /^\x1b\[(\d+;\d+;\d+)M/.test(s) ||
    /^\x1b\[<(\d+;\d+;\d+)([mM])/.test(s) ||
    /^\x1b\[<(\d+;\d+;\d+;\d+)&w/.test(s) ||
    /^\x1b\[24([0135])~\[(\d+),(\d+)\]\r/.test(s) ||
    /^\x1b\[(O|I)/.test(s)
  )
}

Terminal.prototype.setScroll = Terminal.prototype.scrollTo = function (offset) {
  this.term.ydisp = offset
  return this.emit('scroll')
}

Terminal.prototype.getScroll = function () {
  return this.term.ydisp
}

Terminal.prototype.scroll = function (offset) {
  this.term.scrollDisp(offset)
  return this.emit('scroll')
}

Terminal.prototype.resetScroll = function () {
  this.term.ydisp = 0
  this.term.ybase = 0
  return this.emit('scroll')
}

Terminal.prototype.getScrollHeight = function () {
  return this.term.rows - 1
}

Terminal.prototype.getScrollPerc = function () {
  return (this.term.ydisp / this.term.ybase) * 100
}

Terminal.prototype.setScrollPerc = function (i) {
  return this.setScroll(((i / 100) * this.term.ybase) | 0)
}

Terminal.prototype.screenshot = function (xi, xl, yi, yl) {
  xi = 0 + (xi || 0)
  if (xl != null) {
    xl = 0 + (xl || 0)
  } else {
    xl = this.term.lines[0].length
  }
  yi = 0 + (yi || 0)
  if (yl != null) {
    yl = 0 + (yl || 0)
  } else {
    yl = this.term.lines.length
  }
  return this.screen.screenshot(xi, xl, yi, yl, this.term)
}

Terminal.prototype.kill = function () {
  if (this.pty) {
    this.pty.destroy()
    this.pty.kill()
  }
  this.term.refresh = function () {}
  this.term.write('\x1b[H\x1b[J')
  if (this.term._blink) {
    clearInterval(this.term._blink)
  }
  this.term.destroy()
}

/**
 * Expose
 */

module.exports = Terminal
