/*
 * Offer functions for Canvas backups
 *
 */

/* eslint-disable no-console */

import sharp from 'sharp';
import fs from 'fs';
import { commandOptions } from 'redis';

import Palette from './Palette';
import { TILE_SIZE } from './constants';


/*
 * take chunk buffer and pad it to a specific length
 * Fill missing pixels with zeros
 * @param length target length
 */
function padChunk(chunk, length) {
  let retChunk = chunk;
  if (!chunk || !chunk.length) {
    retChunk = Buffer.alloc(length);
  } else if (chunk.length < length) {
    const padding = Buffer.alloc(length - chunk.length);
    retChunk = Buffer.concat([chunk, padding]);
  }
  return retChunk;
}

/*
 * Copy canvases from one redis instance to another
 * @param canvasRedis redis from where to get the data
 * @param backupRedis redis where to write the data to
 * @param canvases Object with all canvas informations
 */
export async function updateBackupRedis(canvasRedis, backupRedis, canvases) {
  const ids = Object.keys(canvases);
  for (let i = 0; i < ids.length; i += 1) {
    const id = ids[i];
    const canvas = canvases[id];
    if (canvas.v || canvas.hid) {
      // ignore 3D and hiddedn canvases
      continue;
    }
    const chunksXY = (canvas.size / TILE_SIZE);
    console.log('Copy Chunks to backup redis...');
    const startTime = Date.now();
    let amount = 0;
    for (let x = 0; x < chunksXY; x++) {
      for (let y = 0; y < chunksXY; y++) {
        const key = `ch:${id}:${x}:${y}`;
        let chunk = null;

        try {
          // eslint-disable-next-line no-await-in-loop
          chunk = await canvasRedis.get(
            commandOptions({ returnBuffers: true }),
            key,
          );
        } catch (error) {
          console.error(
            // eslint-disable-next-line max-len
            new Error(`Could not get chunk ${key} from redis: ${error.message}`),
          );
        }
        if (chunk) {
          try {
            // eslint-disable-next-line no-await-in-loop
            await backupRedis.set(key, chunk);
            amount += 1;
          } catch (error) {
            console.error(
              // eslint-disable-next-line max-len
              new Error(`Could not create chunk ${key} in backup-redis: ${error.message}`),
            );
          }
        }
      }
    }
    const time = Date.now() - startTime;
    console.log(`Finished Copying ${amount} chunks in ${time}ms.`);
  }
}


/*
 * Create incremential PNG tile backup between two redis canvases
 * @param canvasRedis redis from where to get the data
 * @param backupRedis redis where to write the data to
 * @param canvases Object with all canvas informations
 */
export async function incrementialBackupRedis(
  canvasRedis,
  backupRedis,
  canvases,
  backupDir,
) {
  const ids = Object.keys(canvases);
  for (let i = 0; i < ids.length; i += 1) {
    const id = ids[i];

    const canvas = canvases[id];
    if (canvas.v || canvas.hid) {
      // ignore 3D and hidden canvases
      continue;
    }

    const canvasBackupDir = `${backupDir}/${id}`;
    if (!fs.existsSync(canvasBackupDir)) {
      fs.mkdirSync(canvasBackupDir);
    }
    const date = new Date();
    let hours = date.getUTCHours();
    let minutes = date.getUTCMinutes();
    if (hours < 10) hours = `0${hours}`;
    if (minutes < 10) minutes = `0${minutes}`;
    const canvasTileBackupDir = `${canvasBackupDir}/${hours}${minutes}`;
    console.log(`Using folder ${canvasTileBackupDir}`);
    if (!fs.existsSync(canvasTileBackupDir)) {
      fs.mkdirSync(canvasTileBackupDir);
    }

    const palette = new Palette(canvas.colors);
    const chunksXY = (canvas.size / TILE_SIZE);
    console.log('Creating Incremential Backup...');
    const startTime = Date.now();
    let amount = 0;
    for (let x = 0; x < chunksXY; x++) {
      const xBackupDir = `${canvasTileBackupDir}/${x}`;
      let createdDir = false;

      for (let y = 0; y < chunksXY; y++) {
        const key = `ch:${id}:${x}:${y}`;

        let curChunk = null;
        try {
          // eslint-disable-next-line no-await-in-loop
          curChunk = await canvasRedis.get(
            commandOptions({ returnBuffers: true }),
            key,
          );
        } catch (error) {
          console.error(
            // eslint-disable-next-line max-len
            new Error(`Could not get chunk ${key} from redis: ${error.message}`),
          );
        }

        let oldChunk = null;
        try {
          // eslint-disable-next-line no-await-in-loop
          oldChunk = await backupRedis.get(
            commandOptions({ returnBuffers: true }),
            key,
          );
        } catch (error) {
          console.error(
            // eslint-disable-next-line max-len
            new Error(`Could not get chunk ${key} from backup-redis: ${error.message}`),
          );
        }

        // is gonna be an Uint32Array
        let tileBuffer = null;

        try {
          if (!oldChunk && !curChunk) {
            continue;
          }
          if (oldChunk && !curChunk) {
            // one does not exist
            curChunk = Buffer.alloc(TILE_SIZE * TILE_SIZE);
            tileBuffer = palette.buffer2ABGR(curChunk);
          } else if (!oldChunk && curChunk) {
            tileBuffer = new Uint32Array(TILE_SIZE * TILE_SIZE);
            const pxl = 0;
            while (pxl < curChunk.length) {
              const clrIndex = curChunk[pxl] & 0x3F;
              if (clrIndex > 0) {
                const color = palette.abgr[clrIndex];
                tileBuffer[pxl] = color;
              }
            }
          } else {
            if (curChunk.length < oldChunk.length) {
              curChunk = padChunk(curChunk, oldChunk.length);
            } else if (curChunk.length > oldChunk.length) {
              oldChunk = padChunk(oldChunk, curChunk.length);
            }
            // both exist and are the same length
            tileBuffer = new Uint32Array(TILE_SIZE * TILE_SIZE);
            let pxl = 0;
            while (pxl < curChunk.length) {
              if (curChunk[pxl] !== oldChunk[pxl]) {
                const color = palette.abgr[curChunk[pxl] & 0x3F];
                tileBuffer[pxl] = color;
              }
              pxl += 1;
            }
          }
        } catch (error) {
          console.error(
            // eslint-disable-next-line max-len
            new Error(`Could not populate incremential backup data of chunk ${key}: ${error.message}`),
          );
          continue;
        }

        if (tileBuffer) {
          try {
            if (!createdDir && !fs.existsSync(xBackupDir)) {
              createdDir = true;
              fs.mkdirSync(xBackupDir);
            }
            const filename = `${xBackupDir}/${y}.png`;
            // eslint-disable-next-line no-await-in-loop
            await sharp(
              Buffer.from(tileBuffer.buffer), {
                raw: {
                  width: TILE_SIZE,
                  height: TILE_SIZE,
                  channels: 4,
                },
              },
            ).toFile(filename);
            amount += 1;
          } catch (error) {
            console.error(
              // eslint-disable-next-line max-len
              new Error(`Could not save incremential backup of chunk ${key}: ${error.message}`),
            );
            continue;
          }
        }
      }
    }
    const time = Date.now() - startTime;
    console.log(
      `Finished Incremential backup of ${amount} chunks in ${time}ms.`,
    );
  }
}


/*
 * Backup all tiles as PNG files into folder
 * @param redisClient RedisClient
 * @param canvases Object with the informations to all canvases
 * @param backupDir directory where to save png tiles
 */
export async function createPngBackup(
  redisClient,
  canvases,
  backupDir,
) {
  const ids = Object.keys(canvases);
  for (let i = 0; i < ids.length; i += 1) {
    const id = ids[i];

    const canvasBackupDir = `${backupDir}/${id}`;
    if (!fs.existsSync(canvasBackupDir)) {
      fs.mkdirSync(canvasBackupDir);
    }
    const canvasTileBackupDir = `${canvasBackupDir}/tiles`;
    if (!fs.existsSync(canvasTileBackupDir)) {
      fs.mkdirSync(canvasTileBackupDir);
    }

    const canvas = canvases[id];
    const palette = new Palette(canvas.colors);
    const chunksXY = (canvas.size / TILE_SIZE);
    console.log('Create PNG tiles from backup...');
    const startTime = Date.now();
    let amount = 0;
    for (let x = 0; x < chunksXY; x++) {
      const xBackupDir = `${canvasTileBackupDir}/${x}`;
      if (!fs.existsSync(xBackupDir)) {
        fs.mkdirSync(xBackupDir);
      }
      for (let y = 0; y < chunksXY; y++) {
        const key = `ch:${id}:${x}:${y}`;

        let chunk = null;
        try {
          // eslint-disable-next-line no-await-in-loop
          chunk = await redisClient.get(
            commandOptions({ returnBuffers: true }),
            key,
          );
        } catch (error) {
          console.error(
            // eslint-disable-next-line max-len
            new Error(`Could not get chunk ${key} from redis: ${error.message}`),
          );
        }
        if (chunk && chunk.length) {
          chunk = padChunk(chunk, TILE_SIZE * TILE_SIZE);
          const textureBuffer = palette.buffer2RGB(chunk);
          const filename = `${xBackupDir}/${y}.png`;
          try {
            // eslint-disable-next-line no-await-in-loop
            await sharp(
              Buffer.from(textureBuffer.buffer), {
                raw: {
                  width: TILE_SIZE,
                  height: TILE_SIZE,
                  channels: 3,
                },
              },
            ).toFile(filename);
          } catch (error) {
            console.error(
              // eslint-disable-next-line max-len
              new Error(`Could not save daily backup of chunk ${key}: ${error.message}`),
            );
            continue;
          }
          amount += 1;
        }
      }
    }
    const time = Date.now() - startTime;
    console.log(
      `Finished creating PNG backup of ${amount} chunks in ${time}ms.`,
    );
  }
}