from __future__ import absolute_import

import json
import datetime
import os
import os.path
import sys
import traceback

from distutils import log

from .base import BaseBuildCommand


class BuildAssetsCommand(BaseBuildCommand):
    user_options = BaseBuildCommand.user_options + [
        ('asset-json-path=', None,
         'Relative path for JSON manifest. Defaults to {dist_name}/assets.json'),
        ('inplace', 'i',
         "ignore build-lib and put compiled javascript files into the source " +
         "directory alongside your pure Python modules"),
        ('force', 'f',
         "Force rebuilding of static content. Defaults to rebuilding on version "
         "change detection."),
    ]

    description = 'build static media assets'

    def initialize_options(self):
        self.asset_json_path = '{}/assets.json'.format(
            self.distribution.get_name(),
        )
        BaseBuildCommand.initialize_options(self)

    def get_dist_paths(self):
        return [
            'src/sentry/static/sentry/dist',
        ]

    def get_manifest_additions(self):
        return (
            'src/' + self.asset_json_path,
        )

    def _get_package_version(self):
        """
        Attempt to get the most correct current version of Sentry.
        """
        pkg_path = os.path.join(self.work_path, 'src')

        sys.path.insert(0, pkg_path)
        try:
            import sentry
        except Exception:
            version = None
            build = None
        else:
            log.info('pulled version information from \'sentry\' module'.format(
                     sentry.__file__))
            version = self.distribution.get_version()
            build = sentry.__build__
        finally:
            sys.path.pop(0)

        if not (version and build):
            json_path = self.get_asset_json_path()
            try:
                with open(json_path) as fp:
                    data = json.loads(fp.read())
            except Exception:
                pass
            else:
                log.info('pulled version information from \'{}\''.format(
                    json_path,
                ))
                version, build = data['version'], data['build']

        return {
            'version': version,
            'build': build,
        }

    def _needs_static(self, version_info):
        json_path = self.get_asset_json_path()
        if not os.path.exists(json_path):
            return True

        with open(json_path) as fp:
            data = json.load(fp)
        if data.get('version') != version_info.get('version'):
            return True
        if data.get('build') != version_info.get('build'):
            return True
        return False

    def _needs_built(self):
        if BaseBuildCommand._needs_built(self):
            return True
        version_info = self._get_package_version()
        return self._needs_static(version_info)

    def _build(self):
        version_info = self._get_package_version()
        log.info('building assets for {} v{} (build {})'.format(
            self.distribution.get_name(),
            version_info['version'] or 'UNKNOWN',
            version_info['build'] or 'UNKNOWN',
        ))
        if not version_info['version'] or not version_info['build']:
            log.fatal('Could not determine sentry version or build')
            sys.exit(1)

        try:
            self._build_static()
        except Exception:
            traceback.print_exc()
            log.fatal('unable to build Sentry\'s static assets!\n'
                      'Hint: You might be running an invalid version of NPM.')
            sys.exit(1)

        log.info('writing version manifest')
        manifest = self._write_version_file(version_info)
        log.info('recorded manifest\n{}'.format(
            json.dumps(manifest, indent=2),
        ))

    def _build_static(self):
        # By setting NODE_ENV=production, a few things happen
        #   * React optimizes out certain code paths
        #   * Webpack will add version strings to built/referenced assets
        env = dict(os.environ)
        env['SENTRY_STATIC_DIST_PATH'] = self.sentry_static_dist_path
        env['NODE_ENV'] = 'production'
        self._run_command(['node_modules/.bin/webpack', '-p', '--bail'],
                          env=env)

    def _write_version_file(self, version_info):
        manifest = {
            'createdAt': datetime.datetime.utcnow().isoformat() + 'Z',
            'version': version_info['version'],
            'build': version_info['build'],
        }
        with open(self.get_asset_json_path(), 'w') as fp:
            json.dump(manifest, fp)
        return manifest

    @property
    def sentry_static_dist_path(self):
        return os.path.abspath(os.path.join(
            self.build_lib, 'sentry/static/sentry/dist'))

    def get_asset_json_path(self):
        return os.path.abspath(os.path.join(
            self.build_lib, self.asset_json_path))
