import os
import json

from datetime import datetime
from string import Template
from typing import List, Tuple, Iterator, Optional
from dataclasses import fields

try:
    from distutils.dir_util import copy_tree
except ImportError:
    print('[X] Missing "distutils" python package. To install it, run:')
    print('    pip install distutils')

from schema import Link, ArchiveIndex, ArchiveResult
from config import (
    OUTPUT_DIR,
    TEMPLATES_DIR,
    GIT_SHA,
    FOOTER_INFO,
    TIMEOUT,
)
from util import (
    merge_links,
    chmod_file,
    urlencode,
    derived_link_info,
    wget_output_path,
    ExtendedEncoder,
    enforce_types,
    TimedProgress,
)
from parse import parse_links
from links import validate_links
from logs import (
    log_indexing_process_started,
    log_indexing_started,
    log_indexing_finished,
    log_parsing_started,
    log_parsing_finished,
)

TITLE_LOADING_MSG = 'Not yet archived...'


### Homepage index for all the links

@enforce_types
def write_links_index(out_dir: str, links: List[Link], finished: bool=False) -> None:
    """create index.html file for a given list of links"""

    log_indexing_process_started()

    log_indexing_started(out_dir, 'index.json')
    timer = TimedProgress(TIMEOUT * 2, prefix='      ')
    write_json_links_index(out_dir, links)
    timer.end()
    log_indexing_finished(out_dir, 'index.json')
    
    log_indexing_started(out_dir, 'index.html')
    timer = TimedProgress(TIMEOUT * 2, prefix='      ')
    write_html_links_index(out_dir, links, finished=finished)
    timer.end()
    log_indexing_finished(out_dir, 'index.html')


@enforce_types
def load_links_index(out_dir: str=OUTPUT_DIR, import_path: Optional[str]=None) -> Tuple[List[Link], List[Link]]:
    """parse and load existing index with any new links from import_path merged in"""

    existing_links: List[Link] = []
    if out_dir:
        existing_links = list(parse_json_links_index(out_dir))

    new_links: List[Link] = []
    if import_path:
        # parse and validate the import file
        log_parsing_started(import_path)
        raw_links, parser_name = parse_links(import_path)
        new_links = list(validate_links(raw_links))

    # merge existing links in out_dir and new links
    all_links = list(validate_links(existing_links + new_links))
    num_new_links = len(all_links) - len(existing_links)

    if import_path and parser_name:
        log_parsing_finished(num_new_links, parser_name)

    return all_links, new_links


@enforce_types
def write_json_links_index(out_dir: str, links: List[Link]) -> None:
    """write the json link index to a given path"""

    assert isinstance(links, List), 'Links must be a list, not a generator.'
    assert isinstance(links[0].history, dict)
    assert isinstance(links[0].sources, list)

    if links[0].history.get('title'):
        assert isinstance(links[0].history['title'][0], ArchiveResult)

    if links[0].sources:
        assert isinstance(links[0].sources[0], str)

    path = os.path.join(out_dir, 'index.json')

    index_json = ArchiveIndex(
        info='ArchiveBox Index',
        source='https://github.com/pirate/ArchiveBox',
        docs='https://github.com/pirate/ArchiveBox/wiki',
        version=GIT_SHA,
        num_links=len(links),
        updated=datetime.now(),
        links=links,
    )

    assert isinstance(index_json._asdict(), dict)

    with open(path, 'w', encoding='utf-8') as f:
        json.dump(index_json._asdict(), f, indent=4, cls=ExtendedEncoder)

    chmod_file(path)


@enforce_types
def parse_json_links_index(out_dir: str=OUTPUT_DIR) -> Iterator[Link]:
    """parse a archive index json file and return the list of links"""

    allowed_fields = {f.name for f in fields(Link)}

    index_path = os.path.join(out_dir, 'index.json')
    if os.path.exists(index_path):
        with open(index_path, 'r', encoding='utf-8') as f:
            links = json.load(f)['links']
            for link_json in links:
                yield Link(**{
                    key: val
                    for key, val in link_json.items()
                    if key in allowed_fields
                })

    return ()


@enforce_types
def write_html_links_index(out_dir: str, links: List[Link], finished: bool=False) -> None:
    """write the html link index to a given path"""

    path = os.path.join(out_dir, 'index.html')

    copy_tree(os.path.join(TEMPLATES_DIR, 'static'), os.path.join(out_dir, 'static'))

    with open(os.path.join(out_dir, 'robots.txt'), 'w+') as f:
        f.write('User-agent: *\nDisallow: /')

    with open(os.path.join(TEMPLATES_DIR, 'index.html'), 'r', encoding='utf-8') as f:
        index_html = f.read()

    with open(os.path.join(TEMPLATES_DIR, 'index_row.html'), 'r', encoding='utf-8') as f:
        link_row_html = f.read()

    link_rows = '\n'.join(
        Template(link_row_html).substitute(**{
            **derived_link_info(link),
            'title': (
                link.title
                or (link.base_url if link.is_archived else TITLE_LOADING_MSG)
            ),
            'tags': (link.tags or '') + (' {}'.format(link.extension) if link.is_static else ''),
            'favicon_url': (
                os.path.join('archive', link.timestamp, 'favicon.ico')
                # if link['is_archived'] else 'data:image/gif;base64,R0lGODlhAQABAAD/ACwAAAAAAQABAAACADs='
            ),
            'archive_url': urlencode(
                wget_output_path(link) or 'index.html'
            ),
        })
        for link in links
    )

    template_vars = {
        'num_links': len(links),
        'date_updated': datetime.now().strftime('%Y-%m-%d'),
        'time_updated': datetime.now().strftime('%Y-%m-%d %H:%M'),
        'footer_info': FOOTER_INFO,
        'git_sha': GIT_SHA,
        'short_git_sha': GIT_SHA[:8],
        'rows': link_rows,
        'status': 'finished' if finished else 'running',
    }

    with open(path, 'w', encoding='utf-8') as f:
        f.write(Template(index_html).substitute(**template_vars))

    chmod_file(path)


@enforce_types
def patch_links_index(link: Link, out_dir: str=OUTPUT_DIR) -> None:
    """hack to in-place update one row's info in the generated index html"""

    title = link.title or link.latest_outputs()['title']
    successful = link.num_outputs

    # Patch JSON index
    changed = False
    json_file_links = parse_json_links_index(out_dir)
    patched_links = []
    for saved_link in json_file_links:
        if saved_link.url == link.url:
            patched_links.append(saved_link.overwrite(
                title=title,
                history=link.history,
                updated=link.updated,
            ))
        else:
            patched_links.append(saved_link)
    
    write_json_links_index(out_dir, patched_links)

    # Patch HTML index
    html_path = os.path.join(out_dir, 'index.html')
    html = open(html_path, 'r').read().split('\n')
    for idx, line in enumerate(html):
        if title and ('<span data-title-for="{}"'.format(link.url) in line):
            html[idx] = '<span>{}</span>'.format(title)
        elif successful and ('<span data-number-for="{}"'.format(link.url) in line):
            html[idx] = '<span>{}</span>'.format(successful)
            break

    with open(html_path, 'w') as f:
        f.write('\n'.join(html))


### Individual link index

@enforce_types
def write_link_index(out_dir: str, link: Link) -> None:
    write_json_link_index(out_dir, link)
    write_html_link_index(out_dir, link)


@enforce_types
def write_json_link_index(out_dir: str, link: Link) -> None:
    """write a json file with some info about the link"""
    
    path = os.path.join(out_dir, 'index.json')

    with open(path, 'w', encoding='utf-8') as f:
        json.dump(link._asdict(), f, indent=4, cls=ExtendedEncoder)

    chmod_file(path)


@enforce_types
def parse_json_link_index(out_dir: str) -> Optional[Link]:
    """load the json link index from a given directory"""
    existing_index = os.path.join(out_dir, 'index.json')
    if os.path.exists(existing_index):
        with open(existing_index, 'r', encoding='utf-8') as f:
            link_json = json.load(f)
            return Link(**link_json)
    return None


@enforce_types
def load_json_link_index(out_dir: str, link: Link) -> Link:
    """check for an existing link archive in the given directory, 
       and load+merge it into the given link dict
    """
    existing_link = parse_json_link_index(out_dir)
    if existing_link:
        return merge_links(existing_link, link)
    return link


@enforce_types
def write_html_link_index(out_dir: str, link: Link) -> None:
    with open(os.path.join(TEMPLATES_DIR, 'link_index.html'), 'r', encoding='utf-8') as f:
        link_html = f.read()

    path = os.path.join(out_dir, 'index.html')

    with open(path, 'w', encoding='utf-8') as f:
        f.write(Template(link_html).substitute({
            **derived_link_info(link),
            'title': (
                link.title
                or (link.base_url if link.is_archived else TITLE_LOADING_MSG)
            ),
            'archive_url': urlencode(
                wget_output_path(link)
                or (link.domain if link.is_archived else 'about:blank')
            ),
            'extension': link.extension or 'html',
            'tags': link.tags or 'untagged',
            'status': 'archived' if link.is_archived else 'not yet archived',
            'status_color': 'success' if link.is_archived else 'danger',
        }))

    chmod_file(path)