"""Company-metadata discovery: given just a name (plus optional user
hints), proposes official_website/industry/country/region/headquarters/
aliases/competitors/public_identifiers and a preview of sources the
pipeline would start monitoring - all before anything is persisted. This
is the "System performs company discovery" step between "user enters a
name" and "user confirms/edits" in the onboarding flow.

Two independent, deliberately-separated concerns per the architecture
direction:
- SearchProvider answers "where should we look" (this module's job).
- The LLM only ever analyzes evidence this module already gathered - see
  app/prompts/company_profile.py's docstring. It is never asked to recall
  facts about the company from its own training data.

Runs exactly once, at onboarding time, driven by an explicit user action
(the wizard's "Discover" step) - never re-triggered by scheduled monitoring
runs. Source *persistence* still happens exactly as it already did before
this module existed: lazily, on the company's first monitoring run (see
tasks/collection.py). This module only ever previews what that step would
find, via the same collector.discover() calls, without writing anything.
"""

from __future__ import annotations

from app.analysis.llm.base import LLMProvider
from app.collectors.base import CompanyContext
from app.collectors.extraction import extract_readable_text
from app.collectors.registry import get_collector
from app.collectors.robots import is_allowed
from app.core.config import Settings
from app.core.http import FetchError, SsrfBlockedError, fetch_with_retries
from app.core.logging import get_logger
from app.models.enums import SourceType
from app.prompts.company_profile import extract_company_profile
from app.schemas.discovery import DiscoveredCompanyProfile, PotentialSource
from app.search.base import SearchProvider

logger = get_logger(__name__)

# A "{name} official website" search frequently ranks a reference/social
# page above the company's own domain for well-known companies (observed
# live: Brave's top result for "Stripe official website" was Stripe's
# Wikipedia article, not stripe.com). Picking that as `official_website`
# then feeds a wrong base domain into every downstream source-preview
# collector. Skip these hosts when a better-ranked alternative exists in
# the same result set, rather than blindly taking the top hit.
_NON_CORPORATE_HOSTS = (
    "wikipedia.org",
    "linkedin.com",
    "crunchbase.com",
    "bloomberg.com",
    "facebook.com",
    "twitter.com",
    "x.com",
    "youtube.com",
    "reddit.com",
    "glassdoor.com",
)


def _is_non_corporate_host(url: str) -> bool:
    host = url.split("//", 1)[-1].split("/", 1)[0].lower()
    return any(host == d or host.endswith(f".{d}") for d in _NON_CORPORATE_HOSTS)


# Same set collection_service.py's discover_sources_for_company already
# discovers from for a real company - kept in sync deliberately, not
# imported, since this module previews without a persisted Company/Source
# and the coupling would only make both harder to read.
_PREVIEWABLE_TYPES = (
    SourceType.WEBSITE,
    SourceType.GITHUB,
    SourceType.SEC_EDGAR,
    SourceType.JOB_POSTING,
    SourceType.RSS,
    SourceType.GOV_CONTRACT,
    SourceType.PATENT,
)


async def _resolve_official_website(
    search: SearchProvider, name: str, hint: str | None
) -> tuple[str | None, list[str]]:
    if hint:
        return hint, []
    results = await search.search(f"{name} official website", count=3)
    if not results:
        return None, []
    best = next((r for r in results if not _is_non_corporate_host(r.url)), results[0])
    return best.url, [best.url]


async def _fetch_homepage_text(
    settings: Settings, official_website: str | None
) -> tuple[str | None, list[str]]:
    if not official_website:
        return None, []
    try:
        if not await is_allowed(official_website, settings=settings):
            return None, []
        result = await fetch_with_retries(official_website, settings=settings, max_attempts=1)
    except (FetchError, SsrfBlockedError) as exc:
        logger.info("discovery_homepage_fetch_failed", url=official_website, error=str(exc))
        return None, []

    if result.status_code >= 400:
        return None, []

    text, _method = extract_readable_text(result.text, official_website)
    return (text or None), [official_website]


async def _preview_sources(
    context: CompanyContext,
) -> list[PotentialSource]:
    previews: list[PotentialSource] = []
    for source_type in _PREVIEWABLE_TYPES:
        collector = get_collector(source_type)
        try:
            discovered = await collector.discover(context)
        except Exception as exc:  # pragma: no cover - defensive, preview is best-effort
            logger.warning(
                "discovery_source_preview_failed", source_type=source_type, error=str(exc)
            )
            continue
        previews.extend(
            PotentialSource(source_type=d.source_type, name=d.name, base_url=d.base_url)
            for d in discovered
        )
    return previews


async def discover_company_profile(
    search: SearchProvider,
    llm: LLMProvider,
    settings: Settings,
    *,
    name: str,
    official_website: str | None,
    monitoring_focus: str | None,
    competitor_names: list[str],
    alias_names: list[str],
) -> DiscoveredCompanyProfile:
    resolved_website, consulted_website = await _resolve_official_website(
        search, name, official_website
    )
    homepage_text, consulted_homepage = await _fetch_homepage_text(settings, resolved_website)

    search_results = []
    consulted_queries: list[str] = []
    for query in (f"{name} headquarters", f"{name} competitors", f"{name} formerly known as"):
        results = await search.search(query, count=3)
        search_results.extend({"query": query, **r.model_dump()} for r in results)
        consulted_queries.append(query)

    extraction = await extract_company_profile(
        llm,
        company_name=name,
        homepage_url=resolved_website,
        homepage_text=homepage_text,
        search_results=search_results,
    )

    context = CompanyContext(
        id="pending",
        name=name,
        official_website=resolved_website,
        monitoring_focus=monitoring_focus,
        uspto_api_key=settings.uspto_api_key,
    )
    # Individual collectors already handle a missing official_website
    # gracefully (e.g. JobPostingCollector.discover returns [] rather than
    # raising) - GitHub/SEC EDGAR search by name and don't need one at all.
    potential_sources = await _preview_sources(context)

    return DiscoveredCompanyProfile(
        name=name,
        official_website=resolved_website,
        description=extraction.description,
        monitoring_focus=monitoring_focus,
        industry=extraction.industry,
        country=extraction.country,
        region=extraction.region,
        headquarters=extraction.headquarters,
        aliases=alias_names or extraction.aliases,
        competitors=competitor_names or extraction.competitors,
        public_identifiers={pi.key: pi.value for pi in extraction.public_identifiers},
        potential_sources=potential_sources,
        sources_consulted=[*consulted_website, *consulted_homepage, *consulted_queries],
    )