# This file is part of the MapProxy project.
# Copyright (C) 2012 Omniscale <http://omniscale.de>
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from __future__ import print_function, division

import os
import re
import shlex
import sys
import optparse

import yaml

from mapproxy.srs import SRS
from mapproxy.config.coverage import load_coverage
from mapproxy.config.loader import (
    load_configuration, ConfigurationError,
    CacheConfiguration, GridConfiguration,
    ProxyConfiguration
)
from mapproxy.util.coverage import BBOXCoverage
from mapproxy.seed.util import ProgressLog, format_bbox
from mapproxy.seed.seeder import SeedTask, seed_task
from mapproxy.config import spec as conf_spec
from mapproxy.util.ext.dictspec.validator import validate, ValidationError

__all__ = [
    'SRS', 'load_coverage', 'load_configuration', 'ConfigurationError', 'CacheConfiguration', 'GridConfiguration',
    'ProxyConfiguration', 'BBOXCoverage']


def parse_levels(level_str):
    """
    >>> parse_levels('1,2,3,6')
    [1, 2, 3, 6]
    >>> parse_levels('1..6')
    [1, 2, 3, 4, 5, 6]
    >>> parse_levels('1..6, 8, 9, 13..14')
    [1, 2, 3, 4, 5, 6, 8, 9, 13, 14]
    """
    levels = set()
    for part in level_str.split(','):
        part = part.strip()
        if re.match(r'\d+..\d+', part):
            from_level, to_level = part.split('..')
            levels.update(list(range(int(from_level), int(to_level) + 1)))
        else:
            levels.add(int(part))

    return sorted(levels)


def resolve_source(source_name, conf):
    """
    Resolves the source with the given name.

    >>> config = ProxyConfiguration({'sources': {'mysource': {'type': 'wms'}}})
    >>> resolve_source('mysource', config)
    (<mapproxy.config.loader.WMSSourceConfiguration object at 0x...>, False)

    >>> config = ProxyConfiguration({'caches': {'mysource': {}}})
    >>> resolve_source('mysource', config)
    (<mapproxy.config.loader.CacheConfiguration object at 0x...>, True)

    >>> config = ProxyConfiguration({'caches': {'mysource': {'type': 'foo'}}})
    >>> resolve_source('nonexistingsource', config)
    (None, None)

    :param source_name: The name of the source to resolve.
    :param conf: The mapproxy config to resolve from.
    :rtype: (dict, bool) A tuple containing the resolved source and a boolean
        indicating if the resolved source is a cache (True), or a source (False).
    """
    resolved_source = conf.sources.get(source_name)
    if resolved_source is not None:
        return resolved_source, False
    resolved_source = conf.caches.get(source_name)
    if resolved_source is not None:
        return resolved_source, True
    return None, None


def parse_grid_definition(definition):
    """
    >>> sorted(parse_grid_definition("res=[10000,1000,100,10] srs=EPSG:4326 bbox=5,50,10,60").items())
    [('bbox', '5,50,10,60'), ('res', [10000, 1000, 100, 10]), ('srs', 'EPSG:4326')]
    """
    args = shlex.split(definition)
    grid_conf = {}
    for arg in args:
        key, value = arg.split('=')
        value = yaml.safe_load(value)
        grid_conf[key] = value

    validate(conf_spec.grid_opts, grid_conf)
    return grid_conf


def supports_tiled_access(mgr):
    if len(mgr.sources) == 1 and getattr(mgr.sources[0], 'supports_meta_tiles') is False:
        return True
    return False


def format_export_task(task, custom_grid):
    info = []
    if custom_grid:
        grid = "custom grid"
    else:
        grid = "grid '%s'" % task.md['grid_name']

    info.append("Exporting cache '%s' to '%s' with %s in %s" % (
        task.md['cache_name'], task.md['dest'], grid, task.grid.srs.srs_code))
    if task.coverage:
        info.append('  Limited to: %s (EPSG:4326)' % (format_bbox(task.coverage.extent.llbbox), ))
    info.append('  Levels: %s' % (task.levels, ))

    return '\n'.join(info)


def export_command(args=None):
    parser = optparse.OptionParser("%prog export [options] mapproxy_conf")
    parser.add_option("-f", "--mapproxy-conf", dest="mapproxy_conf",
                      help="MapProxy configuration")

    parser.add_option("-q", "--quiet",
                      action="count", dest="quiet", default=0,
                      help="reduce number of messages to stdout, repeat to disable progress output")

    parser.add_option("--source", dest="source",
                      help="source to export (source or cache)")

    parser.add_option("--grid",
                      help="grid for export. either the name of an existing grid or "
                      "the grid definition as a string")

    parser.add_option("--dest",
                      help="destination of the export (directory or filename)")

    parser.add_option("--type",
                      help="type of the export format")

    parser.add_option("--levels",
                      help="levels to export: e.g 1,2,3 or 1..10")

    parser.add_option("--fetch-missing-tiles", dest="fetch_missing_tiles",
                      action='store_true', default=False,
                      help="if missing tiles should be fetched from the sources")

    parser.add_option("--force",
                      action='store_true', default=False,
                      help="overwrite/append to existing --dest files/directories")

    parser.add_option("-n", "--dry-run",
                      action="store_true", default=False,
                      help="do not export, just print output")

    parser.add_option("-c", "--concurrency", type="int",
                      dest="concurrency", default=1,
                      help="number of parallel export processes")

    parser.add_option("--coverage",
                      help="the coverage for the export as a BBOX string, WKT file "
                      "or OGR datasource")
    parser.add_option("--srs",
                      help="the SRS of the coverage")
    parser.add_option("--where",
                      help="filter for OGR coverages")

    from mapproxy.script.util import setup_logging
    import logging
    setup_logging(logging.WARN)

    if args:
        args = args[1:]  # remove script name

    (options, args) = parser.parse_args(args)

    if not options.mapproxy_conf:
        if len(args) != 1:
            parser.print_help()
            sys.exit(1)
        else:
            options.mapproxy_conf = args[0]

    required_options = ['mapproxy_conf', 'grid', 'source', 'dest', 'levels']
    for required in required_options:
        if not getattr(options, required):
            print('ERROR: missing required option --%s' % required.replace('_', '-'), file=sys.stderr)
            parser.print_help()
            sys.exit(1)

    try:
        conf = load_configuration(options.mapproxy_conf)
    except IOError as e:
        print('ERROR: ', "%s: '%s'" % (e.strerror, e.filename), file=sys.stderr)
        sys.exit(2)
    except ConfigurationError as e:
        print(e, file=sys.stderr)
        print('ERROR: invalid configuration (see above)', file=sys.stderr)
        sys.exit(2)

    if '=' in options.grid:
        try:
            grid_conf = parse_grid_definition(options.grid)
        except ValidationError as ex:
            print('ERROR: invalid grid configuration', file=sys.stderr)
            for error in ex.errors:
                print(' ', error, file=sys.stderr)
            sys.exit(2)
        except ValueError:
            print('ERROR: invalid grid configuration', file=sys.stderr)
            sys.exit(2)
        options.grid = 'tmp_mapproxy_export_grid'
        grid_conf['name'] = options.grid
        custom_grid = True
        conf.grids[options.grid] = GridConfiguration(grid_conf, conf)
    else:
        custom_grid = False

    if os.path.exists(options.dest) and not options.force:
        print('ERROR: destination exists, remove first or use --force', file=sys.stderr)
        sys.exit(2)

    cache_conf = {
        'name': 'export',
        'grids': [options.grid],
        'sources': [options.source],
    }

    resolved_source, source_is_cache = resolve_source(options.source, conf)
    if source_is_cache:
        image_format = resolved_source.conf.get('format') or resolved_source.defaults.get('format')
        if image_format is not None:
            cache_conf['format'] = image_format
        if image_format == 'mixed':
            request_format = resolved_source.conf.get('request_format') or 'image/png'
            cache_conf['request_format'] = request_format

    if options.type == 'mbtile':
        cache_conf['cache'] = {
            'type': 'mbtiles',
            'filename': options.dest,
        }
    elif options.type == 'sqlite':
        cache_conf['cache'] = {
            'type': 'sqlite',
            'directory': options.dest,
        }
    elif options.type == 'geopackage':
        cache_conf['cache'] = {
            'type': 'geopackage',
            'filename': options.dest,
        }
    elif options.type == 'compact-v1':
        cache_conf['cache'] = {
            'type': 'compact',
            'version': 1,
            'directory': options.dest,
        }
    elif options.type == 'compact-v2':
        cache_conf['cache'] = {
            'type': 'compact',
            'version': 2,
            'directory': options.dest,
        }
    elif options.type in ('tc', 'mapproxy'):
        cache_conf['cache'] = {
            'type': 'file',
            'directory': options.dest,
        }
    elif options.type == 'arcgis':
        cache_conf['cache'] = {
            'type': 'file',
            'directory_layout': 'arcgis',
            'directory': options.dest,
        }
    elif options.type in ('tms', None):  # default
        cache_conf['cache'] = {
            'type': 'file',
            'directory_layout': 'tms',
            'directory': options.dest,
        }
    else:
        print('ERROR: unsupported --type %s' % (options.type, ), file=sys.stderr)
        sys.exit(2)

    if not options.fetch_missing_tiles:
        for source in conf.sources.values():
            source.conf['seed_only'] = True

    tile_grid, extent, mgr = CacheConfiguration(cache_conf, conf).caches()[0]

    levels = parse_levels(options.levels)
    if levels[-1] >= tile_grid.levels:
        print('ERROR: destination grid only has %d levels' % tile_grid.levels, file=sys.stderr)
        sys.exit(2)

    if options.srs:
        srs = SRS(options.srs)
    else:
        srs = tile_grid.srs

    if options.coverage:
        seed_coverage = load_coverage(
            {'datasource': options.coverage, 'srs': srs, 'where': options.where},
            base_path=os.getcwd())
    else:
        seed_coverage = BBOXCoverage(tile_grid.bbox, tile_grid.srs)

    if not supports_tiled_access(mgr):
        print('WARN: grids are incompatible. needs to scale/reproject tiles for export.', file=sys.stderr)

    md = dict(name='export', cache_name='cache', grid_name=options.grid, dest=options.dest)
    task = SeedTask(md, mgr, levels, 1, seed_coverage)

    print(format_export_task(task, custom_grid=custom_grid))

    logger = ProgressLog(verbose=options.quiet == 0, silent=options.quiet >= 2)
    try:
        seed_task(task, progress_logger=logger, dry_run=options.dry_run,
                  concurrency=options.concurrency)
    except KeyboardInterrupt:
        print('stopping...', file=sys.stderr)
        sys.exit(2)
