var path = require('path');
var fs = require('fs');

var Q = require('q');
var wrench = require('wrench');
var globby = require('globby');

var git = require('./git');

var copy = require('./util').copy;

function getCacheDir() {
  return path.relative(process.cwd(), path.resolve(__dirname, '../.cache'));
}

function getRemoteUrl(dir, remote) {
  var repo;
  return git(['config', '--get', 'remote.' + remote + '.url'], dir)
      .progress(function(chunk) {
        repo = String(chunk).split(/[\n\r]/).shift();
      })
      .then(function() {
        if (repo) {
          return Q.resolve(repo);
        } else {
          return Q.reject(new Error(
              'Failed to get repo URL from options or current directory.'));
        }
      })
      .fail(function(err) {
        return Q.reject(new Error(
            'Failed to get remote.' + remote + '.url (task must either be ' +
            'run in a git repository with a configured ' + remote + ' remote ' +
            'or must be configured with the "repo" option).'));
      });
}

function getRepo(options) {
  if (options.repo) {
    return Q.resolve(options.repo);
  } else {
    return getRemoteUrl(process.cwd(), options.remote);
  }
}


/**
 * Push a git branch to a remote (pushes gh-pages by default).
 * @param {string} basePath The base path.
 * @param {Object} config Publish options.
 * @param {Function} callback Callback.
 */
exports.publish = function publish(basePath, config, callback) {
  if (typeof config === 'function') {
    callback = config;
    config = {};
  }

  var defaults = {
    add: false,
    git: 'git',
    clone: getCacheDir(),
    dotfiles: false,
    branch: 'gh-pages',
    remote: 'origin',
    src: '**/*',
    only: '.',
    push: true,
    message: 'Updates',
    silent: false,
    logger: function() {}
  };

  // override defaults with any task options
  // TODO: Require Node >= 4 and use Object.assign
  var options = {};
  for (var d in defaults) {
    options[d] = defaults[d];
  }
  for (var c in config) {
    options[c] = config[c];
  }

  function log(message) {
    if (!options.silent) {
      options.logger(message);
    }
  }

  if (!callback) {
    callback = function(err) {
      if (err) {
        log(err.message);
      }
    };
  }

  function done(err) {
    try {
      callback(err);
    } catch (err2) {
      log('Publish callback threw: ', err2.message);
    }
  }

  try {
    if (!fs.statSync(basePath).isDirectory()) {
      done(new Error('The "base" option must be an existing directory'));
      return;
    }
  } catch (err) {
    done(err);
    return;
  }

  var files = globby.sync(options.src, {
    cwd: basePath,
    dot: options.dotfiles
  }).filter(function(file) {
    return !fs.statSync(path.join(basePath, file)).isDirectory();
  });

  if (!Array.isArray(files) || files.length === 0) {
    done(new Error('Files must be provided in the "src" property.'));
    return;
  }

  var only = globby.sync(options.only, {cwd: basePath});

  git.exe(options.git);

  var repoUrl;
  getRepo(options)
      .then(function(repo) {
        repoUrl = repo;
        log('Cloning ' + repo + ' into ' + options.clone);
        return git.clone(repo, options.clone, options.branch, options);
      })
      .then(function() {
        return getRemoteUrl(options.clone, options.remote)
            .then(function(url) {
              if (url !== repoUrl) {
                var message = 'Remote url mismatch.  Got "' + url + '" ' +
                    'but expected "' + repoUrl + '" in ' + options.clone +
                    '.  If you have changed your "repo" option, try ' +
                    'running the "clean" task first.';
                return Q.reject(new Error(message));
              } else {
                return Q.resolve();
              }
            });
      })
      .then(function() {
        // only required if someone mucks with the checkout between builds
        log('Cleaning');
        return git.clean(options.clone);
      })
      .then(function() {
        log('Fetching ' + options.remote);
        return git.fetch(options.remote, options.clone);
      })
      .then(function() {
        log('Checking out ' + options.remote + '/' +
            options.branch);
        return git.checkout(options.remote, options.branch,
            options.clone);
      })
      .then(function() {
        if (!options.add) {
          log('Removing files');
          return git.rm(only.join(' '), options.clone);
        } else {
          return Q.resolve();
        }
      })
      .then(function() {
        log('Copying files');
        return copy(files, basePath, options.clone);
      })
      .then(function() {
        log('Adding all');
        return git.add('.', options.clone);
      })
      .then(function() {
        if (options.user) {
          return git(['config', 'user.email', options.user.email],
              options.clone)
              .then(function() {
                return git(['config', 'user.name', options.user.name],
                    options.clone);
              });
        } else {
          return Q.resolve();
        }
      })
      .then(function() {
        log('Committing');
        return git.commit(options.message, options.clone);
      })
      .then(function() {
        if (options.tag) {
          log('Tagging');
          var deferred = Q.defer();
          git.tag(options.tag, options.clone)
            .then(function() {
              return deferred.resolve();
            })
            .fail(function(error) {
              // tagging failed probably because this tag alredy exists
              log('Tagging failed, continuing');
              options.logger(error);
              return deferred.resolve();
            });
          return deferred.promise;
        } else {
          return Q.resolve();
        }
      })
      .then(function() {
        if (options.push) {
          log('Pushing');
          return git.push(options.remote, options.branch,
              options.clone);
        } else {
          return Q.resolve();
        }
      })
      .then(function() {
        done();
      }, function(error) {
        if (options.silent) {
          error = new Error(
              'Unspecified error (run without silent option for detail)');
        }
        done(error);
      });
};


/**
 * Clean the cache directory.
 */
exports.clean = function clean() {
  wrench.rmdirSyncRecursive(getCacheDir(), true);
};