import json
import os
from datetime import datetime, timezone
from view_common import fmt_bytes, relative_time, BLOCKLISTS_DIR
from factory import e


def _blocklist_stats_html(cfg):
    rows = ''
    for bl in cfg.get('dns_blocking', {}).get('blocklists', []):
        name = e(bl.get('name', ''))
        save_as = bl.get('save_as', '')
        bl_path = f'{BLOCKLISTS_DIR}/{save_as}' if save_as else ''
        try:
            with open(bl_path) as f:
                entries = sum(1 for _ in f)
            mtime = int(os.path.getmtime(bl_path))
            size_str = fmt_bytes(os.path.getsize(bl_path))
            last_refreshed = (
                f'{datetime.fromtimestamp(mtime).strftime("%Y-%m-%d %H:%M")}'
                f' ({relative_time(mtime, datetime.now(tz=timezone.utc).timestamp())} ago)'
            )
        except Exception:
            entries, size_str, last_refreshed = '-', '-', 'Never'
        rows += (
            '<tr>'
            f'<td class="table-cell">{name}</td>'
            f'<td class="table-cell">{entries}</td>'
            f'<td class="table-cell">{size_str}</td>'
            f'<td class="table-cell">{e(last_refreshed)}</td>'
            '</tr>'
        )
    if not rows:
        return ''
    return (
        '<table class="data-table"><thead><tr>'
        '<th class="table-header">Blocklist</th>'
        '<th class="table-header">Entries</th>'
        '<th class="table-header">Size</th>'
        '<th class="table-header">Last Refreshed</th>'
        '</tr></thead>'
        f'<tbody>{rows}</tbody></table>'
    )


def collect_tokens(cfg):
    dns_blk_gen = cfg.get('dns_blocking', {}).get('general', {})
    return {
        'GENERAL_LOG_MAX_KB':         str(dns_blk_gen.get('log_max_kb', '-')),
        'GENERAL_LOG_ERRORS_ONLY':    'true' if dns_blk_gen.get('log_errors_only') else 'false',
        'GENERAL_DAILY_EXECUTE_TIME': str(dns_blk_gen.get('daily_execute_time_24hr_local', '-')),
        'BLOCKLIST_STATS_HTML':       _blocklist_stats_html(cfg),
        'BLOCKLIST_FORMAT_OPTIONS':   json.dumps([
            {'value': 'hosts',   'label': 'hosts (hosts file format)'},
            {'value': 'dnsmasq', 'label': 'dnsmasq (local=/ syntax)'},
        ]),
    }