from __future__ import annotations

from datetime import datetime
from typing import Any, Dict, List, Optional, Tuple

from intel.models import Candidate
from intel.utils import parse_dt

from . import cisa_kev, github_global, html_links, nvd_api, osv_api, rss_feed


HANDLERS = {
    "ghsa-global": github_global.fetch,
    "osv-batch": osv_api.fetch,
    "kev-json": cisa_kev.fetch,
    "nvd-search": nvd_api.fetch,
    "rss-feed": rss_feed.fetch,
    "html-links": html_links.fetch,
}


def _passes_since(candidate: Candidate, since_dt: Optional[datetime], include_undated: bool) -> bool:
    if since_dt is None:
        return True
    timestamps = [parse_dt(candidate.updated_at), parse_dt(candidate.published_at)]
    valid = [item for item in timestamps if item is not None]
    if not valid:
        return include_undated
    return max(valid) >= since_dt


def collect_candidates(
    source_map: Dict[str, Any],
    since_dt: Optional[datetime] = None,
    tier: Optional[str] = None,
    include_undated: bool = False,
) -> Tuple[List[Candidate], List[str]]:
    all_candidates: List[Candidate] = []
    failures: List[str] = []

    for system in source_map["systems"]:
        if tier and system.get("tier") != tier:
            continue
        for bucket_name in ("official_sources", "ecosystem_sources", "research_sources"):
            for source in system.get(bucket_name, []):
                handler = HANDLERS.get(source["kind"])
                if handler is None:
                    failures.append(f"Unsupported source kind {source['kind']} for {system['system_id']}")
                    continue
                try:
                    items = handler(system, source)
                    for item in items:
                        if _passes_since(item, since_dt, include_undated):
                            all_candidates.append(item)
                except Exception as exc:
                    failures.append(f"{system['system_id']}::{source['name']}::{exc.__class__.__name__}")
    return all_candidates, failures