import csv
import re
from datetime import datetime
from pathlib import Path
from typing import Any, Dict, List

EXPORT_DIR = Path("exports")
LATEST_CSV = EXPORT_DIR / "latest.csv"
ARCHIVE_PREFIX = "adm_export_"

CSV_FIELDS = ["Title", "UPC"]


def _clean_title(raw_title: str, studio: str = "") -> str:
    if not raw_title:
        return ""
    t = str(raw_title).strip()
    # Remove explicit URLs and common URL-like tokens
    t = re.sub(r"https?://\S+", "", t, flags=re.IGNORECASE)
    t = re.sub(r"www\.[^\s,]+", "", t, flags=re.IGNORECASE)
    # Remove stray backslashes left from escaped quotes in scraped text
    t = t.replace("\\", "")
    # Remove domain-like tokens (example.com, example.co.uk, cdn.example.com/...)
    t = re.sub(r"\b[\w-]+\.(?:com|net|org|io|co|uk|ca|de|jp|au|us|info|biz|online)(?:/[^\s]*)?\b", "", t, flags=re.IGNORECASE)
    # Remove "- DVD -" and variants (DVDs, DVD's, DVDS) between title and studio
    t = re.sub(r"\s*-\s*DVD(?:s|'s)?\s*-\s*", " - ", t, flags=re.IGNORECASE)

    # Remove parenthetical content that contains dvd or urls
    t = re.sub(r"\([^)]*(?:dvd|https?://|www\.|/)[^)]*\)", "", t, flags=re.IGNORECASE)
    # Remove standalone 'DVD' tokens and common variants like DVD's or DVDs
    t = re.sub(r"\bDVD(?:['’]s|s)?\b", "", t, flags=re.IGNORECASE)
    # Remove leftover multiple separators and repeated dashes
    t = re.sub(r"[-]{2,}", "-", t)
    t = re.sub(r"\s*[-–—]\s*", " - ", t)
    # Collapse multiple spaces
    t = re.sub(r"\s{2,}", " ", t).strip()

    # If the studio name is embedded in a longer marketing title, keep only
    # the title through the studio token and discard the trailing promo copy.
    s = (studio or "").strip()
    if s:
        studio_match = re.search(re.escape(s), t, flags=re.IGNORECASE)
        if studio_match:
            t = t[:studio_match.end()].strip()
        else:
            # Remove occurrences of studio name elsewhere to avoid duplicates,
            # then append the canonical studio suffix.
            try:
                t = re.sub(re.escape(s), "", t, flags=re.IGNORECASE)
            except re.error:
                pass
            t = t.strip(" -\t\n\r")
            if t:
                t = f"{t} - {s}"
            else:
                t = s

    # Final cleanup: trim and remove stray punctuation at ends
    t = t.strip()
    t = re.sub(r"^[\-\s,:;]+|[\-\s,:;]+$", "", t)
    return t


def _normalize_record(record: Dict[str, Any], fallback_studio: str = "") -> Dict[str, str]:
    raw_title = record.get("title") or record.get("Title") or ""
    studio = (record.get("studio_name") or record.get("studio") or fallback_studio or "").strip()
    title = _clean_title(raw_title, studio)
    # Final guarantee: keep only "Movie Title - Studio", drop everything after
    parts = title.split(" - ")
    if len(parts) > 2:
        title = " - ".join(parts[:2]).strip(" -,")
    return {
        "Title": title,
        "UPC": str(record.get("upc") or record.get("UPC") or "").strip(),
    }


def save_csv(records: List[Dict[str, Any]], fallback_studio: str = "") -> str:
    EXPORT_DIR.mkdir(exist_ok=True)
    timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
    archive_path = EXPORT_DIR / f"{ARCHIVE_PREFIX}{timestamp}.csv"

    rows = [_normalize_record(record, fallback_studio=fallback_studio) for record in records]

    filtered_rows = []
    seen_upc = set()
    for row in rows:
        upc = row.get("UPC", "").strip()
        if not upc:
            filtered_rows.append(row)
            continue
        if upc in seen_upc:
            continue
        seen_upc.add(upc)
        filtered_rows.append(row)

    for path in [archive_path, LATEST_CSV]:
        with path.open("w", newline="", encoding="utf-8-sig") as handle:
            writer = csv.DictWriter(handle, fieldnames=CSV_FIELDS)
            writer.writeheader()
            writer.writerows(filtered_rows)

    return str(LATEST_CSV)