"""每资源版本检测票据和局部发布；拒绝较早检测的迟到结果。"""
from owned_thread import run_owned_thread
import uuid
from github_archive import commit_sha, source_signature
from github_source import select_github_token
from proxy_access import read_proxy_item


def _entry(versions, item_id):
    if not isinstance(versions, dict):
        raise ValueError('invalid version source')
    entry = versions.get(item_id)
    if entry is None:
        return {}
    if isinstance(entry, str):
        return {'hash': entry}
    if not isinstance(entry, dict):
        raise ValueError('invalid version record')
    return dict(entry)


def _without_cache(entry):
    return {key: value for key, value in entry.items()
            if key not in ('cached_at', 'zip_size') and not key.startswith('archive_')}


def begin_probe(store, item_id):
    item = read_proxy_item(store, item_id)
    token = select_github_token(item)
    source = source_signature(item, token)
    ticket = uuid.uuid4().hex
    def update(versions):
        entry = _entry(versions, item_id)
        entry['_probe_ticket'] = ticket
        entry['_probe_source'] = source
        versions[item_id] = entry
    store.atomic_update('versions.json', update, default_data={})
    return dict(item=item, token=token, source=source, ticket=ticket)


def finish_probe(store, operation, sha):
    sha = commit_sha(sha)
    item_id = operation['item']['id']
    current = read_proxy_item(store, item_id)
    if source_signature(current, select_github_token(current)) != operation['source']:
        return None
    def update(versions):
        entry = _entry(versions, item_id)
        if entry.get('_probe_ticket') != operation['ticket'] or entry.get('_probe_source') != operation['source']:
            return None
        changed = entry.get('hash') != sha[:7]
        if (changed or entry.get('version_source') not in (None, operation['source'])
                or entry.get('version_commit') not in (None, sha)
                or entry.get('archive_commit') not in (None, sha)):
            entry = _without_cache(entry)
        entry.update(hash=sha[:7], version_commit=sha, version_source=operation['source'])
        entry.pop('_probe_ticket', None); entry.pop('_probe_source', None)
        versions[item_id] = entry
        return dict(item=current, token=operation['token'], commit=sha, changed=changed)
    return store.atomic_update('versions.json', update, default_data={})


def invalidate_source(store, item_id):
    """旧编辑回调也读取最新资源；已属于最新来源的确认记录保持。"""
    current = read_proxy_item(store, item_id)
    try:
        source = source_signature(current, select_github_token(current))
    except ValueError:
        source = None
    def update(versions):
        entry = _entry(versions, item_id)
        if source is not None and entry.get('version_source') == source:
            return False
        entry = _without_cache(entry)
        for key in ('version_commit', '_probe_ticket', '_probe_source'):
            entry.pop(key, None)
        entry.update(hash='', version_source=source)
        versions[item_id] = entry
        return True
    return store.atomic_update('versions.json', update, default_data={})


async def refresh_resource_version(store, item_id):
    from 云端_定时版本检测引擎 import fetch_github_commit
    operation = await run_owned_thread(begin_probe, store, item_id)
    sha = await fetch_github_commit(operation['item']['link'], operation['token'])
    if not sha:
        return None
    return await run_owned_thread(finish_probe, store, operation, sha)