// Native
const { homedir } = require('os');
const { resolve: resolvePath, join: joinPaths } = require('path');
const EventEmitter = require('events');

// Packages
const bytes = require('bytes');
const chalk = require('chalk');
const resumer = require('resumer');
const retry = require('async-retry');
const splitArray = require('split-array');
const { parse: parseIni } = require('ini');
const { readFile, stat, lstat } = require('fs-promise');

// Ours
const { npm: getNpmFiles, docker: getDockerFiles } = require('./get-files');
const ua = require('./ua');
const hash = require('./hash');
const Agent = require('./agent');
const readMetaData = require('./read-metadata');

// How many concurrent HTTP/2 stream uploads
const MAX_CONCURRENT = 10;

// Check if running windows
const IS_WIN = process.platform.startsWith('win');
const SEP = IS_WIN ? '\\' : '/';

module.exports = class Now extends EventEmitter {
  constructor(url, token, { forceNew = false, debug = false }) {
    super();
    this._token = token;
    this._debug = debug;
    this._forceNew = forceNew;
    this._agent = new Agent(url, { debug });
    this._onRetry = this._onRetry.bind(this);
  }

  async create(
    path,
    {
      wantsPublic,
      quiet = false,
      env = {},
      followSymlinks = true,
      forceNew = false,
      forceSync = false,
      forwardNpm = false,
      deploymentType = 'npm',
      deploymentName,
      isStatic = false
    }
  ) {
    this._path = path;
    this._static = isStatic;

    let files;

    const meta = await readMetaData(path, {
      deploymentType,
      deploymentName,
      quiet,
      isStatic
    });
    const { pkg, name, description, nowConfig, hasNowJson } = meta;
    deploymentType = meta.deploymentType;

    if (this._debug) {
      console.time('> [debug] Getting files');
    }

    const opts = { debug: this._debug, hasNowJson };
    if (deploymentType === 'npm') {
      files = await getNpmFiles(path, pkg, nowConfig, opts);
    } else {
      files = await getDockerFiles(path, nowConfig, opts);
    }

    if (this._debug) {
      console.timeEnd('> [debug] Getting files');
    }

    forwardNpm = forwardNpm || (nowConfig && nowConfig.forwardNpm);

    // Read .npmrc
    let npmrc = {};
    let authToken;
    if (deploymentType === 'npm' && forwardNpm) {
      try {
        npmrc = await readFile(resolvePath(path, '.npmrc'), 'utf8');
        npmrc = parseIni(npmrc);
        authToken = npmrc['//registry.npmjs.org/:_authToken'];
      } catch (err) {
        // Do nothing
      }

      if (!authToken) {
        try {
          npmrc = await readFile(resolvePath(homedir(), '.npmrc'), 'utf8');
          npmrc = parseIni(npmrc);
          authToken = npmrc['//registry.npmjs.org/:_authToken'];
        } catch (err) {
          // Do nothing
        }
      }
    }

    if (this._debug) {
      console.time('> [debug] Computing hashes');
    }

    const pkgDetails = {};
    pkgDetails.name = name;

    Object.assign(pkgDetails, pkg);

    const hashes = await hash(files, isStatic, pkgDetails);

    if (this._debug) {
      console.timeEnd('> [debug] Computing hashes');
    }

    this._files = hashes;

    const engines = (nowConfig && nowConfig.engines) || pkg.engines;

    const deployment = await this.retry(async bail => {
      if (this._debug) {
        console.time('> [debug] /now/create');
      }

      // Flatten the array to contain files to sync where each nested input
      // array has a group of files with the same sha but different path
      const files = await Promise.all(
        Array.prototype.concat.apply(
          [],
          await Promise.all(
            Array.from(this._files).map(async ([sha, { data, names }]) => {
              const statFn = followSymlinks ? stat : lstat;

              return names.map(async name => {
                let mode;

                const getMode = async () => {
                  const st = await statFn(name);
                  return st.mode;
                };

                if (this._static) {
                  if (toRelative(name, this._path) === 'package.json') {
                    mode = 33261;
                  } else {
                    mode = await getMode();
                    name = this.pathInsideContent(name);
                  }
                } else {
                  mode = await getMode();
                }

                return {
                  sha,
                  size: data.length,
                  file: toRelative(name, this._path),
                  mode
                };
              });
            })
          )
        )
      );

      const res = await this._fetch('/now/create', {
        method: 'POST',
        body: {
          env,
          public: wantsPublic,
          forceNew,
          forceSync,
          name,
          description,
          deploymentType,
          registryAuthToken: authToken,
          files,
          engines
        }
      });

      if (this._debug) {
        console.timeEnd('> [debug] /now/create');
      }

      // No retry on 4xx
      let body;
      try {
        body = await res.json();
      } catch (err) {
        throw new Error('Unexpected response');
      }

      if (res.status === 429) {
        let msg = `You reached your 20 deployments limit in the OSS plan.\n`;
        msg += `${chalk.gray('>')} Please run ${chalk.gray('`')}${chalk.cyan('now upgrade')}${chalk.gray('`')} to proceed`;
        const err = new Error(msg);
        err.status = res.status;
        err.retryAfter = 'never';
        return bail(err);
      } else if (res.status >= 400 && res.status < 500) {
        const err = new Error(body.error.message);
        err.userError = true;
        return bail(err);
      } else if (res.status !== 200) {
        throw new Error(body.error.message);
      }

      return body;
    });

    // We report about files whose sizes are too big
    let missingVersion = false;
    if (deployment.warnings) {
      let sizeExceeded = 0;
      deployment.warnings.forEach(warning => {
        if (warning.reason === 'size_limit_exceeded') {
          const { sha, limit } = warning;
          const n = hashes.get(sha).names.pop();
          console.error(
            '> \u001B[31mWarning!\u001B[39m Skipping file %s (size exceeded %s)',
            n,
            bytes(limit)
          );
          hashes.get(sha).names.unshift(n); // Move name (hack, if duplicate matches we report them in order)
          sizeExceeded++;
        } else if (warning.reason === 'node_version_not_found') {
          const { wanted, used } = warning;
          console.error(
            '> \u001B[31mWarning!\u001B[39m Requested node version %s is not available',
            wanted,
            used
          );
          missingVersion = true;
        }
      });

      if (sizeExceeded) {
        console.error(
          `> \u001B[31mWarning!\u001B[39m ${sizeExceeded} of the files ` +
            'exceeded the limit for your plan.\n' +
            `> Please run ${chalk.gray('`')}${chalk.cyan('now upgrade')}${chalk.gray('`')} to upgrade.`
        );
      }
    }

    if (!quiet && deploymentType === 'npm' && deployment.nodeVersion) {
      if (engines && engines.node) {
        if (missingVersion) {
          console.log(
            `> Using Node.js ${chalk.bold(deployment.nodeVersion)} (default)`
          );
        } else {
          console.log(
            `> Using Node.js ${chalk.bold(deployment.nodeVersion)} (requested: ${chalk.dim(`\`${engines.node}\``)})`
          );
        }
      } else {
        console.log(
          `> Using Node.js ${chalk.bold(deployment.nodeVersion)} (default)`
        );
      }
    }

    this._id = deployment.deploymentId;
    this._host = deployment.url;
    this._missing = deployment.missing || [];

    return this._url;
  }

  pathInsideContent(position) {
    const relativePath = toRelative(position, this._path);
    const contentDir = joinPaths(this._path, 'content');
    const newPath = joinPaths(contentDir, relativePath);

    return newPath;
  }

  upload() {
    const parts = splitArray(this._missing, MAX_CONCURRENT);

    if (this._debug) {
      console.log(
        '> [debug] Will upload ' +
          `${this._missing.length} files in ${parts.length} ` +
          `steps of ${MAX_CONCURRENT} uploads.`
      );
    }

    const uploadChunk = () => {
      Promise.all(
        parts.shift().map(sha =>
          retry(
            async (bail, attempt) => {
              const file = this._files.get(sha);
              const { data, names } = file;

              if (this._debug) {
                console.time(`> [debug] /sync #${attempt} ${names.join(' ')}`);
              }

              const stream = resumer().queue(data).end();
              const res = await this._fetch('/now/sync', {
                method: 'POST',
                headers: {
                  'Content-Type': 'application/octet-stream',
                  'Content-Length': data.length,
                  'x-now-deployment-id': this._id,
                  'x-now-sha': sha,
                  'x-now-file': names
                    .map(name => {
                      if (this._static) {
                        name = this.pathInsideContent(name);
                      }

                      return toRelative(encodeURIComponent(name), this._path);
                    })
                    .join(','),
                  'x-now-size': data.length
                },
                body: stream
              });

              if (this._debug) {
                console.timeEnd(
                  `> [debug] /sync #${attempt} ${names.join(' ')}`
                );
              }

              // No retry on 4xx
              if (
                res.status !== 200 && (res.status >= 400 || res.status < 500)
              ) {
                if (this._debug) {
                  console.log(
                    '> [debug] bailing on creating due to %s',
                    res.status
                  );
                }

                return bail(responseError(res));
              }

              this.emit('upload', file);
            },
            { retries: 3, randomize: true, onRetry: this._onRetry }
          ))
      )
        .then(() => parts.length ? uploadChunk() : this.emit('complete'))
        .catch(err => this.emit('error', err));
    };

    uploadChunk();
  }

  async listSecrets() {
    return this.retry(async (bail, attempt) => {
      if (this._debug) {
        console.time(`> [debug] #${attempt} GET /secrets`);
      }

      const res = await this._fetch('/now/secrets');

      if (this._debug) {
        console.timeEnd(`> [debug] #${attempt} GET /secrets`);
      }

      const body = await res.json();
      return body.secrets;
    });
  }

  async list(app) {
    const query = app ? `?app=${encodeURIComponent(app)}` : '';

    const { deployments } = await this.retry(
      async bail => {
        if (this._debug) {
          console.time('> [debug] /list');
        }

        const res = await this._fetch('/now/list' + query);

        if (this._debug) {
          console.timeEnd('> [debug] /list');
        }

        // No retry on 4xx
        if (res.status >= 400 && res.status < 500) {
          if (this._debug) {
            console.log('> [debug] bailing on listing due to %s', res.status);
          }
          return bail(responseError(res));
        }

        if (res.status !== 200) {
          throw new Error('Fetching deployment list failed');
        }

        return res.json();
      },
      { retries: 3, minTimeout: 2500, onRetry: this._onRetry }
    );

    return deployments;
  }

  async listAliases(deploymentId) {
    return this.retry(async () => {
      const res = await this._fetch(
        deploymentId
          ? `/now/deployments/${deploymentId}/aliases`
          : '/now/aliases'
      );
      const body = await res.json();
      return body.aliases;
    });
  }

  async last(app) {
    const deployments = await this.list(app);

    const last = deployments
      .sort((a, b) => {
        return b.created - a.created;
      })
      .shift();

    if (!last) {
      const e = Error(`No deployments found for "${app}"`);
      e.userError = true;
      throw e;
    }

    return last;
  }

  async listDomains() {
    return this.retry(async (bail, attempt) => {
      if (this._debug) {
        console.time(`> [debug] #${attempt} GET /domains`);
      }

      const res = await this._fetch('/domains');

      if (this._debug) {
        console.timeEnd(`> [debug] #${attempt} GET /domains`);
      }

      const body = await res.json();
      return body.domains;
    });
  }

  async getDomain(domain) {
    return this.retry(async (bail, attempt) => {
      if (this._debug) {
        console.time(`> [debug] #${attempt} GET /domains/${domain}`);
      }

      const res = await this._fetch(`/domains/${domain}`);

      if (this._debug) {
        console.timeEnd(`> [debug] #${attempt} GET /domains/${domain}`);
      }

      return res.json();
    });
  }

  getNameservers(domain) {
    return new Promise((resolve, reject) => {
      let fallback = false;

      this.retry(async (bail, attempt) => {
        if (this._debug) {
          console.time(
            `> [debug] #${attempt} GET /whois-ns${fallback ? '-fallback' : ''}`
          );
        }

        const res = await this._fetch(
          `/whois-ns${fallback ? '-fallback' : ''}?domain=${encodeURIComponent(domain)}`
        );

        if (this._debug) {
          console.timeEnd(
            `> [debug] #${attempt} GET /whois-ns${fallback ? '-fallback' : ''}`
          );
        }

        const body = await res.json();

        if (res.status === 200) {
          if (
            (!body.nameservers || body.nameservers.length === 0) && !fallback
          ) {
            // If the nameservers are `null` it's likely
            // that our whois service failed to parse it
            fallback = true;
            throw new Error('Invalid whois response');
          }

          return body;
        }

        if (attempt > 1) {
          fallback = true;
        }

        throw new Error(`Whois error (${res.status}): ${body.error.message}`);
      })
        .then(body => {
          body.nameservers = body.nameservers.filter(ns => {
            // Temporary hack:
            // sometimes we get a response that looks like:
            // ['ns', 'ns', '', '']
            // so we filter the empty ones
            return ns.length;
          });
          resolve(body);
        })
        .catch(err => {
          reject(err);
        });
    });
  }

  // _ensures_ the domain is setup (idempotent)
  setupDomain(name, { isExternal } = {}) {
    return this.retry(async (bail, attempt) => {
      if (this._debug) {
        console.time(`> [debug] #${attempt} POST /domains`);
      }

      const res = await this._fetch('/domains', {
        method: 'POST',
        body: { name, isExternal: Boolean(isExternal) }
      });

      if (this._debug) {
        console.timeEnd(`> [debug] #${attempt} POST /domains`);
      }

      const body = await res.json();

      if (res.status === 403) {
        const code = body.error.code;
        let err;

        if (code === 'custom_domain_needs_upgrade') {
          err = new Error(
            `Custom domains are only enabled for premium accounts. Please upgrade at ${chalk.underline('https://zeit.co/account')}.`
          );
        } else {
          err = new Error(`Not authorized to access domain ${name}`);
        }

        err.userError = true;
        return bail(err);
      } else if (res.status === 409) {
        // Domain already exists
        if (this._debug) {
          console.log('> [debug] Domain already exists (noop)');
        }

        return { uid: body.error.uid, code: body.error.code };
      } else if (
        res.status === 401 &&
        body.error &&
        body.error.code === 'verification_failed'
      ) {
        const err = new Error(body.error.message);
        err.userError = true;
        return bail(err);
      } else if (res.status !== 200) {
        throw new Error(body.error.message);
      }

      return body;
    });
  }

  createCert(domain, { renew } = {}) {
    return this.retry(
      async (bail, attempt) => {
        if (this._debug) {
          console.time(`> [debug] /now/certs #${attempt}`);
        }

        const res = await this._fetch('/now/certs', {
          method: 'POST',
          body: {
            domains: [domain],
            renew
          }
        });

        if (res.status === 304) {
          console.log('> Certificate already issued.');
          return;
        }

        const body = await res.json();

        if (this._debug) {
          console.timeEnd(`> [debug] /now/certs #${attempt}`);
        }

        if (body.error) {
          const { code } = body.error;

          if (code === 'verification_failed') {
            const err = new Error(
              'The certificate issuer failed to verify ownership of the domain. ' +
                'This likely has to do with DNS propagation and caching issues. Please retry later!'
            );
            err.userError = true;
            // Retry
            throw err;
          } else if (code === 'rate_limited') {
            const err = new Error(body.error.message);
            err.userError = true;
            // Dont retry
            return bail(err);
          }

          throw new Error(body.error.message);
        }

        if (res.status !== 200 && res.status !== 304) {
          throw new Error('Unhandled error');
        }
        return body;
      },
      { retries: 5, minTimeout: 30000, maxTimeout: 90000 }
    );
  }

  deleteCert(domain) {
    return this.retry(async (bail, attempt) => {
      if (this._debug) {
        console.time(`> [debug] /now/certs #${attempt}`);
      }

      const res = await this._fetch(`/now/certs/${domain}`, {
        method: 'DELETE'
      });

      if (res.status !== 200) {
        const err = new Error(res.body.error.message);
        err.userError = false;

        if (res.status === 400 || res.status === 404) {
          return bail(err);
        }

        throw err;
      }
    });
  }

  async remove(deploymentId, { hard }) {
    const data = { deploymentId, hard };

    await this.retry(async bail => {
      if (this._debug) {
        console.time('> [debug] /remove');
      }

      const res = await this._fetch('/now/remove', {
        method: 'DELETE',
        body: data
      });

      if (this._debug) {
        console.timeEnd('> [debug] /remove');
      }

      // No retry on 4xx
      if (res.status >= 400 && res.status < 500) {
        if (this._debug) {
          console.log('> [debug] bailing on removal due to %s', res.status);
        }
        return bail(responseError(res));
      }

      if (res.status !== 200) {
        throw new Error('Removing deployment failed');
      }
    });

    return true;
  }

  retry(fn, { retries = 3, maxTimeout = Infinity } = {}) {
    return retry(fn, {
      retries,
      maxTimeout,
      onRetry: this._onRetry
    });
  }

  _onRetry(err) {
    if (this._debug) {
      console.log(`> [debug] Retrying: ${err}\n${err.stack}`);
    }
  }

  close() {
    this._agent.close();
  }

  get id() {
    return this._id;
  }

  get url() {
    return `https://${this._host}`;
  }

  get host() {
    return this._host;
  }

  get syncAmount() {
    if (!this._syncAmount) {
      this._syncAmount = this._missing
        .map(sha => this._files.get(sha).data.length)
        .reduce((a, b) => a + b, 0);
    }
    return this._syncAmount;
  }

  _fetch(_url, opts = {}) {
    opts.headers = opts.headers || {};
    opts.headers.authorization = `Bearer ${this._token}`;
    opts.headers['user-agent'] = ua;
    return this._agent.fetch(_url, opts);
  }
};

function toRelative(path, base) {
  const fullBase = base.endsWith(SEP) ? base : base + SEP;
  let relative = path.substr(fullBase.length);

  if (relative.startsWith(SEP)) {
    relative = relative.substr(1);
  }

  return relative.replace(/\\/g, '/');
}

function responseError(res) {
  const err = new Error('Response error');
  err.status = res.status;

  if (res.status === 429) {
    const retryAfter = res.headers.get('Retry-After');
    if (retryAfter) {
      err.retryAfter = parseInt(retryAfter, 10);
    }
  }

  return err;
}