"""Albanian Supreme Court (Gjykata e Lartë) via the Gatsby page-data JSON API.

Decisions are published as periodic and thematic bulletins under
`/sq/lajme/buletini/`. Each bulletin's detail page exposes its decisions
inline as HTML strings inside `result.data.api.newsArticle.body[].content[].text_sq`,
so we can extract full text without touching the pre-2020 .doc archive.

Civil filter: keep decisions tagged "Kolegji Civil" (Civil College) or
"Kolegjet e Bashkuara" (United Colleges, mixed civil/penal).
"""

import html
import logging
import re
import time
from datetime import date
from typing import Any

import requests

from legex.models.base import Case
from legex.scrapers.base import BaseScraper

log = logging.getLogger(__name__)

API_BASE = "https://www.gjykataelarte.gov.al/page-data"
PUBLIC_BASE = "https://www.gjykataelarte.gov.al"
USER_AGENT = "legex-research (open-data, friendly)"
DELAY_SECONDS = 1.0
MAX_LIST_PAGES = 15

# New-format header (periodik/tematik bulletins 2024+) — standalone line:
#   Vendimi nr. 00-2025-1613 (255), datë 21.10.2025 i Kolegjit Penal
# Followed by Maksima / Fjalë kyçe / Përmbledhje sections.
_DECISION_HEADER_RE = re.compile(
    r"(Vendimi?\s+nr\.?\s*[\w\-\(\)\s]+?,?\s*dat[ëe]\s+\d{1,2}\.\d{1,2}\.\d{4}\s+i\s+Kolegj[a-zëÇçë ]+)",
    re.IGNORECASE,
)

# Old-format mention (informativ/tematik bulletins 2022-2023) — appears inline:
#   Në vendimin nr.00-2022-635, datë 01.04.2022, ...
# College is set by a section heading above ("Kolegji Civil i Gjykatës së Lartë").
_OLD_DECISION_RE = re.compile(
    r"N[ëe]\s+vendim(?:in)?\s+nr[\.\s]*([\d\(\)\s\-––]+?)\s*,?\s*dat[ëe]\s+(\d{1,2})[\.,](\d{1,2})[\.,](\d{4})",
    re.IGNORECASE,
)
_COLLEGE_HEADING_RE = re.compile(
    r"Kolegj[i]?\s+(Civil|Penal|Administrativ|Administrative|Tregtar|"
    r"Bashkuar)[a-zëçÇË]*\s+(?:i\s+)?Gjykat",
    re.IGNORECASE,
)
# Short aliases used inline (KCGJL = Kolegji Civil, KPGJL = Kolegji Penal, KAGJL = Kolegji Administrativ)
_INLINE_COLLEGE_RE = re.compile(r"\bK(C|P|A)GJL\b")
_DOC_LINK_RE = re.compile(
    r"https?://gjykata-media\.s3\.eu-central-1\.amazonaws\.com/[\w\-\.\/]+\.doc",
    re.IGNORECASE,
)

_DECISION_NUM_RE = re.compile(r"nr\.?\s*([\d\-\(\)\s]+?)\s*,", re.IGNORECASE)
_DATE_RE = re.compile(r"dat[ëe]\s+(\d{1,2})\.(\d{1,2})\.(\d{4})")
_KEYWORD_RE = re.compile(
    r"Fjal[ëe]\s*ky[çc]e\s*[-–—]\s*(.+?)(?=P[ëe]rmbledhje|Maksima|$)",
    re.DOTALL | re.IGNORECASE,
)
_MAXIMA_RE = re.compile(
    r"Maksima\s*[-–—]\s*(.+?)(?=Fjal[ëe]\s*ky[çc]e|P[ëe]rmbledhje|$)",
    re.DOTALL | re.IGNORECASE,
)


def _strip_html(raw: str) -> str:
    """Remove HTML tags, decode entities, collapse whitespace."""
    text = re.sub(r"<[^>]+>", "\n", raw)
    text = html.unescape(text)
    text = re.sub(r"\n{3,}", "\n\n", text)
    return text.strip()


def _detect_college(header: str) -> str:
    h = header.lower()
    if "civil" in h:
        return "civil"
    if "penal" in h:
        return "penal"
    if "administrat" in h:
        return "administrative"
    if "bashk" in h:
        return "united"
    return "unknown"


def _parse_iso_date(header: str) -> str | None:
    m = _DATE_RE.search(header)
    if not m:
        return None
    return f"{m.group(3)}-{m.group(2).zfill(2)}-{m.group(1).zfill(2)}"


def _parse_decision_number(header: str) -> str | None:
    m = _DECISION_NUM_RE.search(header)
    if not m:
        return None
    return re.sub(r"\s+", "", m.group(1))


def _fetch_json(session: requests.Session, url: str) -> dict[str, Any] | None:
    try:
        resp = session.get(url, timeout=30)
    except requests.RequestException as e:
        log.warning("AL request error %s: %s", url, e)
        return None
    if resp.status_code == 404:
        return None
    if resp.status_code != 200:
        log.warning("AL HTTP %d for %s", resp.status_code, url)
        return None
    try:
        return resp.json()
    except ValueError:
        log.warning("AL non-JSON response from %s", url)
        return None


def _list_bulletin_slugs(session: requests.Session) -> list[dict[str, Any]]:
    slugs: list[dict[str, Any]] = []
    for page in range(1, MAX_LIST_PAGES + 1):
        url = (
            f"{API_BASE}/sq/lajme/buletini/page-data.json"
            if page == 1
            else f"{API_BASE}/sq/lajme/buletini/{page}/page-data.json"
        )
        data = _fetch_json(session, url)
        if not data:
            break
        articles = (
            data.get("result", {}).get("pageContext", {}).get("articles", [])
        )
        if not articles:
            break
        for a in articles:
            slug = a.get("slug")
            if not slug:
                continue
            title_obj = a.get("title")
            if isinstance(title_obj, dict):
                title = title_obj.get("text_sq", "") or title_obj.get("text_en", "")
            else:
                title = title_obj or ""
            slugs.append(
                {
                    "slug": slug,
                    "publish_date": a.get("publishDate"),
                    "title": title,
                }
            )
        log.info("AL list page %d: %d bulletins (cumulative %d)", page, len(articles), len(slugs))
        time.sleep(DELAY_SECONDS)
    return slugs


def _fetch_bulletin_html(session: requests.Session, slug: str) -> str:
    url = f"{API_BASE}/sq/lajme/buletini/{slug}/page-data.json"
    data = _fetch_json(session, url)
    if not data:
        return ""
    try:
        body = data["result"]["data"]["api"]["newsArticle"]["body"]
    except (KeyError, TypeError):
        return ""
    chunks: list[str] = []
    for block in body:
        if "Paragraph" not in block.get("__typename", ""):
            continue
        for content in block.get("content", []) or []:
            txt = content.get("text_sq") or content.get("text_en") or ""
            if txt:
                chunks.append(txt)
    return "".join(chunks)


def _parse_decisions(
    bulletin_html: str, slug: str, bulletin_title: str
) -> list[dict[str, Any]]:
    plain = _strip_html(bulletin_html)
    parts = _DECISION_HEADER_RE.split(plain)
    if len(parts) < 3:
        # Fall back to the older bulletin layout where decisions are
        # introduced inline by "Në vendimin nr. X, datë Y" mentions.
        return _parse_old_format(plain, slug, bulletin_title)
    decisions: list[dict[str, Any]] = []
    i = 1
    while i < len(parts) - 1:
        header = parts[i].strip()
        body = parts[i + 1].strip()
        i += 2
        if len(body) < 200:
            continue
        decisions.append(
            {
                "header": header,
                "body": body,
                "decision_number": _parse_decision_number(header),
                "iso_date": _parse_iso_date(header),
                "college": _detect_college(header),
                "maxima": (m.group(1).strip() if (m := _MAXIMA_RE.search(body)) else None),
                "keywords": (
                    [k.strip() for k in re.split(r"[,;]", km.group(1)) if k.strip()]
                    if (km := _KEYWORD_RE.search(body))
                    else []
                ),
                "bulletin_slug": slug,
                "bulletin_title": bulletin_title,
                "doc_link": None,
                "format": "new",
            }
        )
    return decisions


def _section_college_at(plain: str, pos: int) -> str:
    """Return the most recent college heading before pos in plain text."""
    head = plain[:pos]
    last: str = "unknown"
    for m in _COLLEGE_HEADING_RE.finditer(head):
        last = _detect_college(m.group(0))
    return last


def _inline_college_at(snippet: str) -> str:
    m = _INLINE_COLLEGE_RE.search(snippet)
    if not m:
        return "unknown"
    return {"C": "civil", "P": "penal", "A": "administrative"}.get(m.group(1), "unknown")


def _parse_old_format(
    plain: str, slug: str, bulletin_title: str
) -> list[dict[str, Any]]:
    matches = list(_OLD_DECISION_RE.finditer(plain))
    if not matches:
        return []

    decisions: list[dict[str, Any]] = []
    for idx, m in enumerate(matches):
        # body spans from this match to the next, capped at ~3000 chars.
        body_end = matches[idx + 1].start() if idx + 1 < len(matches) else m.end() + 3000
        body = plain[m.start():body_end].strip()
        if len(body) < 150:
            continue

        decision_num = re.sub(r"\s+", "", m.group(1))
        iso_date = f"{m.group(4)}-{m.group(3).zfill(2)}-{m.group(2).zfill(2)}"

        # Prefer a college signalled inline (KCGJL / KPGJL / KAGJL inside the
        # summary itself) over the section heading, since some bulletins mix
        # multiple colleges in a single section.
        college = _inline_college_at(body)
        if college == "unknown":
            college = _section_college_at(plain, m.start())

        doc_link_m = _DOC_LINK_RE.search(body)
        doc_link = doc_link_m.group(0) if doc_link_m else None

        decisions.append(
            {
                "header": body[:200],
                "body": body,
                "decision_number": decision_num,
                "iso_date": iso_date,
                "college": college,
                "maxima": None,
                "keywords": [],
                "bulletin_slug": slug,
                "bulletin_title": bulletin_title,
                "doc_link": doc_link,
                "format": "old",
            }
        )
    return decisions


class ALScraper(BaseScraper):
    country = "Albanien"

    def scrape(
        self,
        start_date: date | None = None,
        end_date: date | None = None,
    ) -> list[Case]:
        session = requests.Session()
        session.headers.update(
            {"User-Agent": USER_AGENT, "Accept": "application/json"}
        )

        slugs = _list_bulletin_slugs(session)
        log.info("AL discovered %d bulletins", len(slugs))

        seen: set[str] = set()
        cases: list[Case] = []
        for info in slugs:
            raw_html = _fetch_bulletin_html(session, info["slug"])
            time.sleep(DELAY_SECONDS)
            if not raw_html:
                continue
            decisions = _parse_decisions(raw_html, info["slug"], info["title"])
            log.info("AL %s: %d decisions", info["slug"], len(decisions))

            for d in decisions:
                decision_date: date | None = None
                if d["iso_date"]:
                    try:
                        decision_date = date.fromisoformat(d["iso_date"])
                    except ValueError:
                        decision_date = None
                if start_date and decision_date and decision_date < start_date:
                    continue
                if end_date and decision_date and decision_date > end_date:
                    continue

                case_id = d["decision_number"] or f"AL-{info['slug']}-{len(cases)}"
                if case_id in seen:
                    continue
                seen.add(case_id)

                full_text = f"{d['header']}\n\n{d['body']}" if d["format"] == "new" else d["body"]
                # Prefer the direct .doc URL on S3 (old-format bulletins expose
                # it); fall back to the bulletin page for new-format entries.
                link = d.get("doc_link") or f"{PUBLIC_BASE}/sq/lajme/buletini/{info['slug']}"

                cases.append(
                    Case(
                        case_id=case_id,
                        link=link,
                        decision_date=decision_date,
                        jurisdiction="al",
                        language="sq",
                        full_text=full_text,
                        metadata={
                            "college": d["college"],
                            "decision_number": d["decision_number"],
                            "bulletin_slug": d["bulletin_slug"],
                            "bulletin_title": d["bulletin_title"],
                            "maxima": d["maxima"],
                            "keywords": d["keywords"],
                            "format": d["format"],
                            "doc_link": d.get("doc_link"),
                        },
                    )
                )

        cases.sort(key=lambda c: c.decision_date or date.min, reverse=True)
        log.info("Collected %d Albania cases", len(cases))
        return cases

    @staticmethod
    def civil_filter(cases: list[Case]) -> list[Case]:
        kept = [
            c
            for c in cases
            if (c.metadata or {}).get("college") in {"civil", "united"}
        ]
        log.info("AL civil_filter kept %d/%d", len(kept), len(cases))
        return kept