import os
import re
import sys

from functools import wraps
from collections import defaultdict
from datetime import datetime

from peekable import Peekable

from index import wget_output_path, parse_json_link_index, write_link_index
from links import links_after_timestamp
from config import (
    CHROME_BINARY,
    FETCH_WGET,
    FETCH_WGET_REQUISITES,
    FETCH_PDF,
    FETCH_SCREENSHOT,
    FETCH_DOM,
    FETCH_WARC,
    FETCH_GIT,
    FETCH_MEDIA,
    RESOLUTION,
    CHECK_SSL_VALIDITY,
    SUBMIT_ARCHIVE_DOT_ORG,
    FETCH_FAVICON,
    WGET_USER_AGENT,
    CHROME_USER_DATA_DIR,
    CHROME_SANDBOX,
    TIMEOUT,
    MEDIA_TIMEOUT,
    ANSI,
    ARCHIVE_DIR,
    GIT_DOMAINS,
)
from util import (
    check_dependencies,
    progress,
    chmod_file,
    pretty_path,
    run, PIPE, DEVNULL
)


_RESULTS_TOTALS = {   # globals are bad, mmkay
    'skipped': 0,
    'succeded': 0,
    'failed': 0,
}

def archive_links(archive_path, links, source=None, resume=None):
    check_dependencies()

    to_archive = Peekable(links_after_timestamp(links, resume))
    idx, link = 0, to_archive.peek(0)

    try:
        for idx, link in enumerate(to_archive):
            link_dir = os.path.join(ARCHIVE_DIR, link['timestamp'])
            archive_link(link_dir, link)
    
    except (KeyboardInterrupt, SystemExit, Exception) as e:
        print('{lightyellow}[X] [{now}] Downloading paused on link {timestamp} ({idx}/{total}){reset}'.format(
            **ANSI,
            now=datetime.now().strftime('%Y-%m-%d %H:%M:%S'),
            idx=idx+1,
            timestamp=link['timestamp'],
            total=len(links),
        ))
        print('    Continue where you left off by running:')
        print('        {} {}'.format(
            pretty_path(sys.argv[0]),
            link['timestamp'],
        ))
        if not isinstance(e, KeyboardInterrupt):
            raise e
        raise SystemExit(1)


def archive_link(link_dir, link, overwrite=True):
    """download the DOM, PDF, and a screenshot into a folder named after the link's timestamp"""

    update_existing = os.path.exists(link_dir)
    if update_existing:
        link = {
            **parse_json_link_index(link_dir),
            **link,
        }
    else:
        os.makedirs(link_dir)
    
    log_link_archive(link_dir, link, update_existing)

    if FETCH_FAVICON:
        link = fetch_favicon(link_dir, link, overwrite=overwrite)

    if FETCH_WGET:
        link = fetch_wget(link_dir, link, overwrite=overwrite)

    if FETCH_PDF:
        link = fetch_pdf(link_dir, link, overwrite=overwrite)

    if FETCH_SCREENSHOT:
        link = fetch_screenshot(link_dir, link, overwrite=overwrite)

    if FETCH_DOM:
        link = fetch_dom(link_dir, link, overwrite=overwrite)

    if SUBMIT_ARCHIVE_DOT_ORG:
        link = archive_dot_org(link_dir, link, overwrite=overwrite)

    if FETCH_GIT:
        link = fetch_git(link_dir, link, overwrite=overwrite)

    if FETCH_MEDIA:
        link = fetch_media(link_dir, link, overwrite=overwrite)


    write_link_index(link_dir, link)
    
    return link

def log_link_archive(link_dir, link, update_existing):
    print('[{symbol_color}{symbol}{reset}] [{now}] "{title}"\n    {blue}{url}{reset}'.format(
        symbol='*' if update_existing else '+',
        symbol_color=ANSI['black' if update_existing else 'green'],
        now=datetime.now().strftime('%Y-%m-%d %H:%M:%S'),
        **link,
        **ANSI,
    ))

    print('    > {}{}'.format(pretty_path(link_dir), '' if update_existing else ' (new)'))
    if link['type']:
        print('      i {}'.format(link['type']))



def attach_result_to_link(method):
    """
    Instead of returning a result={output:'...', status:'success'} object,
    attach that result to the links's history & latest fields, then return
    the updated link object.
    """
    def decorator(fetch_func):
        @wraps(fetch_func)
        def timed_fetch_func(link_dir, link, overwrite=False, **kwargs):
            # initialize methods and history json field on link
            link['latest'] = link.get('latest') or {}
            link['latest'][method] = link['latest'].get(method) or None
            link['history'] = link.get('history') or {}
            link['history'][method] = link['history'].get(method) or []

            start_ts = datetime.now().timestamp()

            # if a valid method output is already present, dont run the fetch function
            if link['latest'][method] and not overwrite:
                print('      √ {}'.format(method))
                result = None
            else:
                print('      > {}'.format(method))
                result = fetch_func(link_dir, link, **kwargs)

            end_ts = datetime.now().timestamp()
            duration = str(end_ts * 1000 - start_ts * 1000).split('.')[0]

            # append a history item recording fail/success
            history_entry = {
                'timestamp': str(start_ts).split('.')[0],
            }
            if result is None:
                history_entry['status'] = 'skipped'
            elif isinstance(result.get('output'), Exception):
                history_entry['status'] = 'failed'
                history_entry['duration'] = duration
                history_entry.update(result or {})
                link['history'][method].append(history_entry)
            else:
                history_entry['status'] = 'succeded'
                history_entry['duration'] = duration
                history_entry.update(result or {})
                link['history'][method].append(history_entry)
                link['latest'][method] = result['output']

            _RESULTS_TOTALS[history_entry['status']] += 1
            
            return link
        return timed_fetch_func
    return decorator


@attach_result_to_link('wget')
def fetch_wget(link_dir, link, requisites=FETCH_WGET_REQUISITES, warc=FETCH_WARC, timeout=TIMEOUT):
    """download full site using wget"""

    domain_dir = os.path.join(link_dir, link['domain'])
    existing_file = wget_output_path(link)
    if os.path.exists(domain_dir) and existing_file:
        return {'output': existing_file, 'status': 'skipped'}

    if warc:
        warc_dir = os.path.join(link_dir, 'warc')
        os.makedirs(warc_dir, exist_ok=True)
        warc_path = os.path.join('warc', str(int(datetime.now().timestamp())))

    # WGET CLI Docs: https://www.gnu.org/software/wget/manual/wget.html
    CMD = [
        'wget',
        # '--server-response',  # print headers for better error parsing
        '--no-verbose',
        '--adjust-extension',
        '--convert-links',
        '--force-directories',
        '--backup-converted',
        '--span-hosts',
        '--no-parent',
        '--restrict-file-names=unix',
        '--timeout={}'.format(timeout),
        *(() if warc else ('--timestamping',)),
        *(('--warc-file={}'.format(warc_path),) if warc else ()),
        *(('--page-requisites',) if FETCH_WGET_REQUISITES else ()),
        *(('--user-agent="{}"'.format(WGET_USER_AGENT),) if WGET_USER_AGENT else ()),
        *((() if CHECK_SSL_VALIDITY else ('--no-check-certificate',))),
        link['url'],
    ]
    end = progress(timeout, prefix='      ')
    try:
        result = run(CMD, stdout=PIPE, stderr=PIPE, cwd=link_dir, timeout=timeout)  # index.html
        end()
        output = wget_output_path(link, look_in=domain_dir)

        # Check for common failure cases
        if result.returncode > 0:
            print('        Got wget response code {}:'.format(result.returncode))
            print('\n'.join('          ' + line for line in (result.stdout + result.stderr).decode().rsplit('\n', 3)[-3:] if line.strip()))
            if b'403: Forbidden' in result.stderr:
                raise Exception('403 Forbidden (try changing WGET_USER_AGENT)')
            if b'404: Not Found' in result.stderr:
                raise Exception('404 Not Found')
            if b'ERROR 500: Internal Server Error' in result.stderr:
                raise Exception('500 Internal Server Error')
            raise Exception('Got an error from the server')
    except Exception as e:
        end()
        print('        {}Some resources were skipped: {}{}'.format(ANSI['lightyellow'], e, ANSI['reset']))
        print('        Run to see full output:')
        print('            cd {};'.format(link_dir))
        print('            {}'.format(' '.join(CMD)))
        output = e

    return {
        'cmd': CMD,
        'output': output,
    }


@attach_result_to_link('pdf')
def fetch_pdf(link_dir, link, timeout=TIMEOUT, user_data_dir=CHROME_USER_DATA_DIR):
    """print PDF of site to file using chrome --headless"""

    if link['type'] in ('PDF', 'image'):
        return {'output': wget_output_path(link)}
    
    if os.path.exists(os.path.join(link_dir, 'output.pdf')):
        return {'output': 'output.pdf', 'status': 'skipped'}

    CMD = [
        *chrome_headless(user_data_dir=user_data_dir),
        '--print-to-pdf',
        '--hide-scrollbars',
        '--timeout={}'.format((timeout) * 1000),
        *(() if CHECK_SSL_VALIDITY else ('--disable-web-security', '--ignore-certificate-errors')),
        link['url']
    ]
    end = progress(timeout, prefix='      ')
    try:
        result = run(CMD, stdout=PIPE, stderr=PIPE, cwd=link_dir, timeout=timeout)  # output.pdf
        end()
        if result.returncode:
            print('     ', (result.stderr or result.stdout).decode())
            raise Exception('Failed to print PDF')
        chmod_file('output.pdf', cwd=link_dir)
        output = 'output.pdf'
    except Exception as e:
        end()
        print('        {}Failed: {} {}{}'.format(ANSI['red'], e.__class__.__name__, e, ANSI['reset']))
        print('        Run to see full output:')
        print('            cd {};'.format(link_dir))
        print('            {}'.format(' '.join(CMD)))
        output = e

    return {
        'cmd': CMD,
        'output': output,
    }

@attach_result_to_link('screenshot')
def fetch_screenshot(link_dir, link, timeout=TIMEOUT, user_data_dir=CHROME_USER_DATA_DIR, resolution=RESOLUTION):
    """take screenshot of site using chrome --headless"""

    if link['type'] in ('PDF', 'image'):
        return {'output': wget_output_path(link)}
    
    if os.path.exists(os.path.join(link_dir, 'screenshot.png')):
        return {'output': 'screenshot.png', 'status': 'skipped'}

    CMD = [
        *chrome_headless(user_data_dir=user_data_dir),
        '--screenshot',
        '--window-size={}'.format(resolution),
        '--hide-scrollbars',
        '--timeout={}'.format((timeout) * 1000),
        *(() if CHECK_SSL_VALIDITY else ('--disable-web-security', '--ignore-certificate-errors')),
        # '--full-page',   # TODO: make this actually work using ./bin/screenshot fullPage: true
        link['url'],
    ]
    end = progress(timeout, prefix='      ')
    try:
        result = run(CMD, stdout=PIPE, stderr=PIPE, cwd=link_dir, timeout=timeout)  # sreenshot.png
        end()
        if result.returncode:
            print('     ', (result.stderr or result.stdout).decode())
            raise Exception('Failed to take screenshot')
        chmod_file('screenshot.png', cwd=link_dir)
        output = 'screenshot.png'
    except Exception as e:
        end()
        print('        {}Failed: {} {}{}'.format(ANSI['red'], e.__class__.__name__, e, ANSI['reset']))
        print('        Run to see full output:')
        print('            cd {};'.format(link_dir))
        print('            {}'.format(' '.join(CMD)))
        output = e

    return {
        'cmd': CMD,
        'output': output,
    }
    
@attach_result_to_link('dom')
def fetch_dom(link_dir, link, timeout=TIMEOUT, user_data_dir=CHROME_USER_DATA_DIR):
    """print HTML of site to file using chrome --dump-html"""

    if link['type'] in ('PDF', 'image'):
        return {'output': wget_output_path(link)}
    
    output_path = os.path.join(link_dir, 'output.html')

    if os.path.exists(output_path):
        return {'output': 'output.html', 'status': 'skipped'}

    CMD = [
        *chrome_headless(user_data_dir=user_data_dir),
        '--dump-dom',
        '--timeout={}'.format((timeout) * 1000),
        link['url']
    ]
    end = progress(timeout, prefix='      ')
    try:
        with open(output_path, 'w+') as f:
            result = run(CMD, stdout=f, stderr=PIPE, cwd=link_dir, timeout=timeout)  # output.html
        end()
        if result.returncode:
            print('     ', (result.stderr).decode())
            raise Exception('Failed to fetch DOM')
        chmod_file('output.html', cwd=link_dir)
        output = 'output.html'
    except Exception as e:
        end()
        print('        {}Failed: {} {}{}'.format(ANSI['red'], e.__class__.__name__, e, ANSI['reset']))
        print('        Run to see full output:')
        print('            cd {};'.format(link_dir))
        print('            {}'.format(' '.join(CMD)))
        output = e

    return {
        'cmd': CMD,
        'output': output,
    }

@attach_result_to_link('archive_org')
def archive_dot_org(link_dir, link, timeout=TIMEOUT):
    """submit site to archive.org for archiving via their service, save returned archive url"""

    path = os.path.join(link_dir, 'archive.org.txt')
    if os.path.exists(path):
        archive_org_url = open(path, 'r').read().strip()
        return {'output': archive_org_url, 'status': 'skipped'}

    submit_url = 'https://web.archive.org/save/{}'.format(link['url'])

    success = False
    CMD = [
        'curl',
        '--location',
        '--head',
        '--max-time', str(timeout),
        '--get',
        *(() if CHECK_SSL_VALIDITY else ('--insecure',)),
        submit_url,
    ]
    end = progress(timeout, prefix='      ')
    try:
        result = run(CMD, stdout=PIPE, stderr=DEVNULL, cwd=link_dir, timeout=timeout)  # archive.org.txt
        end()

        # Parse archive.org response headers
        headers = defaultdict(list)

        # lowercase all the header names and store in dict
        for header in result.stdout.splitlines():
            if b':' not in header or not header.strip():
                continue
            name, val = header.decode().split(':', 1)
            headers[name.lower().strip()].append(val.strip())

        # Get successful archive url in "content-location" header or any errors
        content_location = headers['content-location']
        errors = headers['x-archive-wayback-runtime-error']

        if content_location:
            saved_url = 'https://web.archive.org{}'.format(content_location[0])
            success = True
        elif len(errors) == 1 and 'RobotAccessControlException' in errors[0]:
            output = submit_url
            # raise Exception('Archive.org denied by {}/robots.txt'.format(link['domain']))
        elif errors:
            raise Exception(', '.join(errors))
        else:
            raise Exception('Failed to find "content-location" URL header in Archive.org response.')
    except Exception as e:
        end()
        print('        {}Failed: {} {}{}'.format(ANSI['red'], e.__class__.__name__, e, ANSI['reset']))
        print('        Run to see full output:')
        print('            {}'.format(' '.join(CMD)))
        output = e

    if success:
        with open(os.path.join(link_dir, 'archive.org.txt'), 'w', encoding='utf-8') as f:
            f.write(saved_url)
        chmod_file('archive.org.txt', cwd=link_dir)
        output = saved_url

    return {
        'cmd': CMD,
        'output': output,
    }

@attach_result_to_link('favicon')
def fetch_favicon(link_dir, link, timeout=TIMEOUT):
    """download site favicon from google's favicon api"""

    if os.path.exists(os.path.join(link_dir, 'favicon.ico')):
        return {'output': 'favicon.ico', 'status': 'skipped'}

    CMD = [
        'curl',
        '--max-time', str(timeout),
        'https://www.google.com/s2/favicons?domain={domain}'.format(**link),
    ]
    fout = open('{}/favicon.ico'.format(link_dir), 'w')
    end = progress(timeout, prefix='      ')
    try:
        run(CMD, stdout=fout, stderr=DEVNULL, cwd=link_dir, timeout=timeout)  # favicon.ico
        fout.close()
        end()
        chmod_file('favicon.ico', cwd=link_dir)
        output = 'favicon.ico'
    except Exception as e:
        fout.close()
        end()
        print('        {}Failed: {} {}{}'.format(ANSI['red'], e.__class__.__name__, e, ANSI['reset']))
        print('        Run to see full output:')
        print('            {}'.format(' '.join(CMD)))
        output = e

    return {
        'cmd': CMD,
        'output': output,
    }

@attach_result_to_link('media')
def fetch_media(link_dir, link, timeout=MEDIA_TIMEOUT, overwrite=False):
    """Download playlists or individual video, audio, and subtitles using youtube-dl"""


    # import ipdb; ipdb.set_trace()
    output = os.path.join(link_dir, 'media')
    already_done = os.path.exists(output) and os.listdir(output)
    if already_done and not overwrite:
        return {'output': 'media', 'status': 'skipped'}

    os.makedirs(output, exist_ok=True)
    CMD = [
        'youtube-dl',
        '--write-description',
        '--write-info-json',
        '--write-annotations',
        '--yes-playlist',
        '--write-thumbnail',
        '--no-call-home',
        '--no-check-certificate',
        '--user-agent',
        '--all-subs',
        '-x',
        '-k',
        '--audio-format', 'mp3',
        '--audio-quality', '320K',
        '--embed-thumbnail',
        '--add-metadata',
        link['url'],
    ]

    end = progress(timeout, prefix='      ')
    try:
        result = run(CMD, stdout=PIPE, stderr=PIPE, cwd=output, timeout=timeout + 1)  # audio/audio.mp3
        end()
        if result.returncode:
            if b'ERROR: Unsupported URL' in result.stderr:
                pass
            else:
                print('        got youtubedl response code {}:'.format(result.returncode))
                print(result.stderr)
                raise Exception('Failed to download media')
    except Exception as e:
        end()
        print('        {}Failed: {} {}{}'.format(ANSI['red'], e.__class__.__name__, e, ANSI['reset']))
        print('        Run to see full output:')
        print('            cd {};'.format(link_dir))
        print('            {}'.format(' '.join(CMD)))
        output = e

    return {
        'cmd': CMD,
        'output': output,
    }


@attach_result_to_link('git')
def fetch_git(link_dir, link, timeout=TIMEOUT):
    """download full site using git"""

    if not (link['domain'] in GIT_DOMAINS
            or link['url'].endswith('.git')
            or link['type'] == 'git'):
        return

    if os.path.exists(os.path.join(link_dir, 'git')):
        return {'output': 'git', 'status': 'skipped'}

    CMD = ['git', 'clone', '--mirror', '--recursive', link['url'], 'git']
    output = 'git'

    end = progress(timeout, prefix='      ')
    try:
        result = run(CMD, stdout=PIPE, stderr=PIPE, cwd=link_dir, timeout=timeout + 1)  # git/<reponame>
        end()

        if result.returncode > 0:
            print('        got git response code {}:'.format(result.returncode))
            raise Exception('Failed git download')
    except Exception as e:
        end()
        print('        {}Failed: {} {}{}'.format(ANSI['red'], e.__class__.__name__, e, ANSI['reset']))
        print('        Run to see full output:')
        print('            cd {};'.format(link_dir))
        print('            {}'.format(' '.join(CMD)))
        output = e

    return {
        'cmd': CMD,
        'output': output,
    }

def chrome_headless(binary=CHROME_BINARY, user_data_dir=CHROME_USER_DATA_DIR):
    args = [binary, '--headless']  # '--disable-gpu'
    if not CHROME_SANDBOX:
        args.append('--no-sandbox')
    default_profile = os.path.expanduser('~/Library/Application Support/Google/Chrome/Default')
    if user_data_dir:
        args.append('--user-data-dir={}'.format(user_data_dir))
    elif os.path.exists(default_profile):
        args.append('--user-data-dir={}'.format(default_profile))
    return args