'use strict';
import { BufferLengthError } from './errors/BufferLengthError';
import { InvalidValueError } from './errors/InvalidValueError';
import { DPT } from './definitions';

/**
 * <strong>19.001</strong> Date & Time
 *
 * <pre>
 *             +-7-+-6-+-5-+-4-+-3-+-2-+-1-+-0-+-7-+-6-+-5-+-4-+-3-+-2-+-1-+-0-+
 * Field Names | (Year)                        | 0   0   0   0   (Month)       |
 * Encoding    | U   U   U   U   U   U   U   U | r   r   r   r   U   U   U   U |
 *             +-7-+-6-+-5-+-4-+-3-+-2-+-1-+-0-+-7-+-6-+-5-+-4-+-3-+-2-+-1-+-0-+
 *             | 0   0   0   (Day Of Month)    | (DayOfWeek) (Hour)            |
 *             | r   r   r   U   U   U   U   U | U   U   U   U   U   U   U   U |
 *             +-7-+-6-+-5-+-4-+-3-+-2-+-1-+-0-+-7-+-6-+-5-+-4-+-3-+-2-+-1-+-0-+
 *             | 0   0   (Minutes)             | 0   0   (Seconds)             |
 *             | r   r   U   U   U   U   U   U | r   r   U   U   U   U   U   U |
 *             +-7-+-6-+-5-+-4-+-3-+-2-+-1-+-0-+-7-+-6-+-5-+-4-+-3-+-2-+-1-+-0-+
 *             | F  WD  NWD NY  ND  NDoW NT SST| CLQ SRC 0   0   0   0   0   0 |
 *             | B   B   B   B   B   B   B   B | B   B   r   r   r   r   r   r |
 *             +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
 * Format:     8 octets (U<sub>8</sub> [r<sub>4</sub>U<sub>4</sub>] [r<sub>3</sub>U<sub>5</sub>] [r<sub>3</sub>U<sub>5</sub>] [r<sub>2</sub>U<sub>6</sub>] [r<sub>2</sub>U<sub>6</sub>] B<sub>16</sub>)
 * Encoding:
 *             Year  = [0 .. 255]
 *                0 = year 1900
 *                255 = year 2155
 *             Month = [1 .. 12]
 *             DayOfMonth = [1 .. 31]
 *             DayOfWeek = [0 .. 7]
 *                1 = Monday, 2 = Tuesday, 3 = Wednesday, 4 = Thursday, 5 = Friday, 6 = Saturday, 7 = Sunday, 0 = any day
 *             Hour    = [0 .. 24]
 *             Minutes = [0 .. 59]
 *             Seconds = [0 .. 59]
 *             (F)   Fault = {0, 1}
 *                        0 = Normal (no fault)
 *                        1 = Fault
 *             (WD)   WorkingDay = {0, 1}
 *                        0 = No Working Day
 *                        1 = Working Day
 *             (NWD)  NoWorkingDay = {0, 1}
 *                        0 = WorkingDay field valid
 *                        1 = WorkingDay field not valid
 *             (NY)   NoYear = {0, 1}
 *                        0 = Year field valid
 *                        1 = Year field not valid
 *             (ND)   NoDate = {0, 1}
 *                        0 = Month and DayOfMonth fields valid
 *                        1 = Month and DayOfMonth fields not valid
 *             (NDoW) NoDayOfWeek = {0, 1}
 *                        0 = DayOfWeek field valid
 *                        1 = DayOfWeek field not valid
 *             (NT)   NoTime = {0, 1}
 *                        0 = Hour, Minutes and Seconds valid
 *                        1 = Hour, Minutes and Seconds not valid
 *             (SST)  Standard Summer Time = {0, 1}
 *                        0 = UTC+x (standard time)
 *                        1 = UTC+x +1h (summer daylight saving time)
 *             (CLQ)  QualityOfClock = {0, 1}
 *                        0 = Clock without external synchronization signal
 *                        1 = Clock with external synchronization signal (DCF 77, VideoText, ...)
 *             (SRC)  SynchronisationSourceReliability = {0, 1}
 *                        0 = Unreliable Synchronisation (mains, local quartz)
 *                        1 = Reliable Synchronisation (radio, internet)
 * </pre>
 * <p>
 * The encoding of the hour is within the range [0 .. 24] instead of [0 .. 23]. When the hour is set to "24", the
 * values of octet 3 (Minutes) and 2 (Seconds) have to be set to zero.
 * <p>
 * "Fault" is set if one ore more supported fields of the Date & Time information are corrupted. "Fault" is set e.g.
 * power-down if battery backup was not sufficient, after 1st start up of device (clock un-configured) or radio-clock
 * (DCF 77) had no reception for a very long time. "Fault" is usually cleared automatically by the device if the
 * local clock is set or clock data is refreshed
 * <p>
 * The receiver (e.g. a room unit, MMI) will interpret Date&Time with "Fault" as corrupted and will either ignore
 * the message or show --:--:-- or blinking 00:00:00 (as known from Video recorders after power-up).
 */
export class DPT19Result {
  dateTime: Date = new Date()
  dayOfWeek: number = undefined
  f: boolean = false
  wd: boolean = false
  nwd: boolean = false
  ny: boolean = false
  nd: boolean = false
  ndow: boolean = false
  nt: boolean = false
  sst: boolean = false
  internalClock: boolean = true // Assume external clock
  reliability: boolean = false;
}
export class DPT19 implements DPT {
  id = '19';
  name = '8-byte Date+Time';
  bufferLength = 8;

  /**
   * Decode a buffer
   *
   * @param buffer the buffer
   * @returns the DPT value
   */
  decoder(buffer: Buffer): DPT19Result {
    if (buffer.length !== this.bufferLength)
      throw new BufferLengthError(`Invalid buffer length ${buffer.length}/${buffer} for DPT8.  Expected ${this.bufferLength}.`);

    const byte8 = buffer.readUInt8(0)
    const byte7 = buffer.readUInt8(1)
    const byte6 = buffer.readUInt8(2)
    const byte5 = buffer.readUInt8(3)
    const byte4 = buffer.readUInt8(4)
    const byte3 = buffer.readUInt8(5)
    const byte2 = buffer.readUInt8(6)
    const byte1 = buffer.readUInt8(7)

    let year = byte8
    let month = byte7 & 0xF
    const dayOfMonth = byte6 & 0x1F
    let dayOfWeek = byte5 >> 5
    const hourOfDay = byte5 & 0x1F
    const minutes = byte4 & 0x3F
    const seconds = byte3 & 0x3F
    const f = !!(byte2 & 0x80)
    const wd = !!(byte2 & 0x40)
    const nwd = !!(byte2 & 0x20)
    const ny = !!(byte2 & 0x10)
    const nd = !!(byte2 & 0x8)
    const ndow = !!(byte2 & 0x4)
    const nt = !!(byte2 & 0x2)
    const suti = !!(byte2 & 0x1)
    const clq = !!(byte1 & 0x80)
    const reliability = !!(byte1 & 0x40)

    year += 1900

    // Convert month from knx to JavaScript (12 => 11, 11 => 10, ...)
    month -= 1

    // Convert day of week from knx to JavaScript (7 => 0, 0 => undefined)
    if (dayOfWeek === 7) {
      dayOfWeek = 0
    } else if (dayOfWeek === 0) {
      dayOfWeek = undefined
    }

    // Check minutes and seconds if hours equals 24
    if (hourOfDay === 24 && (minutes !== 0 || seconds !== 0)) {
      throw new RangeError('Invalid time (hour of day is 24, but minutes or seconds are not 0)')
    }

    return {
      dateTime: new Date(year, month, dayOfMonth, hourOfDay, minutes, seconds),
      dayOfWeek: dayOfWeek,
      f: f,
      wd: wd,
      nwd: nwd,
      ny: ny,
      nd: nd,
      ndow: ndow,
      nt: nt,
      sst: suti,
      internalClock: clq,
      reliability: reliability
    }
  };

  /**
   * Encode a buffer
   *
   * @param value the value to be converted to buffer
   * @returns the buffer
   */
  encoder(value: DPT19Result | Date): Buffer {
    if (value === undefined || value === null)
      throw new InvalidValueError(`Invalid value [${value}]`)

    let temp: DPT19Result;

    if (value.constructor.name === 'Date') {
      temp = new DPT19Result()
      temp.dateTime = value as Date
      temp.dayOfWeek = (value as Date).getDay()
    } else {
      temp = value as DPT19Result
    }

    let dayOfWeek = temp.dayOfWeek
    const f = !!temp.f ? 1 : 0
    const wd = !!temp.wd ? 1 : 0
    const nwd = !!temp.nwd ? 1 : 0
    const ny = !!temp.ny ? 1 : 0
    const nd = !!temp.nd ? 1 : 0
    const ndow = !!temp.ndow ? 1 : 0
    const nt = !!temp.nt ? 1 : 0
    const sst = !!temp.sst ? 1 : 0
    const clq = !!temp.internalClock ? 1 : 0
    const reliability = !!temp.reliability ? 1 : 0

    // Convert day of week from JavaScript to knx (0 => 7, undefined => 0)
    if (typeof dayOfWeek === 'undefined') {
      dayOfWeek = 0
    } else if (dayOfWeek === 0) {
      dayOfWeek = 7
    }

    const buffer = Buffer.alloc(8, 0)
    buffer.writeUInt8(temp.dateTime.getFullYear() - 1900, 0)
    buffer.writeUInt8(temp.dateTime.getMonth() + 1, 1)
    buffer.writeUInt8(temp.dateTime.getDate(), 2)
    buffer.writeUInt8((dayOfWeek << 5) | temp.dateTime.getHours(), 3)
    buffer.writeUInt8(temp.dateTime.getMinutes(), 4)
    buffer.writeUInt8(temp.dateTime.getSeconds(), 5)
    buffer.writeUInt8((f << 7) | (wd << 6) | (nwd << 5) | (ny << 4) | (nd << 3) | (ndow << 2) | (nt << 1) | sst, 6)
    buffer.writeUInt8(clq << 7 | reliability << 6, 7)

    return buffer
  }
  subtypes: {
    // 19.001
    '001': {
      name: 'DPT_DateTime',
      desc: 'datetime',
    },
  };

}