import os
import re
import json
import shutil
import html
from pathlib import Path
from collections import defaultdict
from difflib import SequenceMatcher

SOURCE_DIR = Path("../original_index")
OUTPUT_DIR = Path("../output")

PAGES_DIR = Path(OUTPUT_DIR / "pages")
REGISTRY_PATH = Path(OUTPUT_DIR / "equivalence_registry.json")
REPORT_PATH = Path(OUTPUT_DIR / "migration_report.txt")

OUTPUT_DIR.mkdir(parents=True, exist_ok=True)
PAGES_DIR.mkdir(parents=True, exist_ok=True)

# --------------------------------------------------
# Helpers
# --------------------------------------------------

INVALID_WIN_CHARS = r'[<>:"/\\|?*]'
ARTICLE_ID_RE = re.compile(r'"wgArticleId":\s*(\d+)')
IS_REDIRECT_RE = re.compile(r'"wgIsRedirect"\s*:\s*true')
NAMESPACE_RE = re.compile(r'"wgCanonicalNamespace"\s*:\s*"([^"]*)"')
WG_TITLE_RE = re.compile(r'"wgTitle"\s*:\s*"([^"]+)"')
SHORT_SLUG_RE = re.compile(r"^[a-z0-9]+[0-9]*$")

def similarity(a, b):
    return SequenceMatcher(None, a, b).ratio()

def normalize_title(title: str) -> str:
    title = title.strip()
    title = title.replace("_", " ")
    title = re.sub(r"\s+", " ", title)
    return title.casefold()


def sanitize_filename(name: str) -> str:
    name = re.sub(INVALID_WIN_CHARS, "_", name)
    return name[:180]


def extract_wg_page_name(page_html: str) -> str | None:
    m = re.search(r'"wgPageName"\s*:\s*"([^"]+)"', page_html)
    if m:
        return html.unescape(m.group(1)).replace("_", " ")
    return None


def extract_page_identity(html: str):
    page = extract_wg_page_name(html)
    if page:
        return page
    m = re.search(r"<title>(.*?) -", html, re.I)
    if m:
        return html.unescape(m.group(1))
    return None


def extract_article_id(html: str) -> int | None:
    m = ARTICLE_ID_RE.search(html)
    if m:
        aid = int(m.group(1))
        if aid > 0:
            return aid
    return None


def extract_internal_redirect(page_html: str):
    m = re.search(r'"wgRedirectedFrom"\s*:\s*"([^"]+)"', page_html)
    if m:
        return html.unescape(m.group(1)).replace("_", " ")
    return None


def extract_namespace(html: str) -> str:
    m = NAMESPACE_RE.search(html)
    if m:
        return m.group(1)
    return ""


def extract_wg_title(page_html):
    m = WG_TITLE_RE.search(page_html)
    if m:
        return html.unescape(m.group(1))
    return None


def normalize_reference_key(key: str) -> str:
    key = normalize_title(key)

    # normalise namespace category
    key = re.sub(r"^category[\s:_]+", "", key)

    # collapse espaces
    key = re.sub(r"\s+", " ", key)

    return key.strip()


# --------------------------------------------------
# Registry structures
# --------------------------------------------------

ignored_pages = []
problems = []
redirects = {}
all_variants = defaultdict(list)

files = list(SOURCE_DIR.glob("*.html"))
print(f"{len(files)} fichiers trouvés")

# --------------------------------------------------
# PASS 1 — analyse et collecte des variantes
# --------------------------------------------------

for i, path in enumerate(files, 1):
    try:
        page_html = path.read_text(encoding="utf-8", errors="ignore")

        article_id = extract_article_id(page_html)
        if not article_id:
            ignored_pages.append(path.name)
            continue

        title = extract_page_identity(page_html)
        if not title:
            problems.append(f"No title: {path}")
            continue

        ns = extract_namespace(page_html)

        # Ignorer certains namespaces
        if ns in ("File", "Template", "User", "Talk", "File talk", "Category talk", "User talk"):
            ignored_pages.append(path.name)
            continue

        title = html.unescape(title)
        norm = normalize_title(title)
        page_name = extract_wg_page_name(page_html)
        full_title = normalize_title(page_name) if page_name else norm
        base_title = norm
        is_redirect = bool(IS_REDIRECT_RE.search(page_html))
        is_category = ns == "Category" or norm.startswith("category:")
        wg_title = extract_wg_title(page_html)

        # Categories
        if ns == "Category":
            m_title = re.search(r'"wgTitle"\s*:\s*"([^"]+)"', page_html)

            if m_title:
                wg_title = html.unescape(m_title.group(1))
                cat_base = normalize_title(wg_title)

                page_norm = normalize_title(page_name) if page_name else None

                if page_norm and page_norm != f"category:{cat_base}":
                    # page réelle déguisée en category
                    base_title = page_norm
                    is_category = False
                else:
                    base_title = cat_base
                    is_category = True
            else:
                base_title = norm.replace("category:", "", 1)
                is_category = True

        # redirect interne
        redir = extract_internal_redirect(page_html)
        if redir:
            redirects[full_title] = normalize_title(redir)

        canonical_key = normalize_reference_key(full_title)
        all_variants[article_id].append({
            "path": path,
            "title": base_title,
            "canonical_key": full_title,
            "article_id": article_id,
            "wg_title": normalize_title(wg_title) if wg_title else None,
            "redirect": is_redirect,
            "is_category": is_category,
        })

    except Exception as e:
        problems.append(f"{path}: {e}")

    if i % 200 == 0:
        print(f"{i}/{len(files)} analysés")
print("Variants collected:", len(all_variants))

# --------------------------------------------------
# PASS 2 — choix des versions canoniques
# --------------------------------------------------

canonical_pages = {}
equivalences = {}
category_replaced = 0
nb_all_cat = 0


def slug_to_title(filename: str) -> str:
    name = Path(filename).stem
    name = re.sub(r"\d+$", "", name)
    return normalize_title(name)


def filename_similarity_score(filename, wg_title):
    if not wg_title:
        return 0

    filename = normalize_title(filename)
    wg_title = normalize_title(wg_title)

    # enlève chiffres suffixes
    filename = re.sub(r"\d+$", "", filename)

    return similarity(filename, wg_title)

def variant_score(v):

    filename = v["path"].stem
    filename_norm = normalize_title(filename)

    similarity_score = filename_similarity_score(
        filename_norm,
        v["wg_title"]
    )

    is_short_slug = bool(
        SHORT_SLUG_RE.match(filename_norm.replace(" ", ""))
    )

    long_title_penalty = (
        "," in filename or
        "_" in filename or
        len(filename) > 40
    )

    return (
        v["is_category"],
        v["redirect"],
        not is_short_slug,
        long_title_penalty,
        -similarity_score,
        len(filename),
        filename.lower(),
    )


for article_id, variants in all_variants.items():

    # tri déterministe
    variants_sorted = sorted(variants, key=variant_score)
    print(f"variants_sorted: {variants_sorted}")

    chosen = variants_sorted[0]

    if all(v["is_category"] for v in variants):
        nb_all_cat += 1

    if chosen["is_category"]:
        category_replaced += 1

    canonical_title = normalize_reference_key(chosen["title"])
    
    canonical_pages[article_id] = {
        "path": chosen["path"],
        "title": canonical_title,
        "redirect": chosen["redirect"],
    }

    # équivalences
    for v in variants:
        equivalences[v["canonical_key"]] = chosen["title"]

equivalences.clear()

def add_equivalence(k, v):
    k = normalize_reference_key(k)
    v = normalize_reference_key(v)

    if k != v:
        equivalences[k] = v

for article_id, variants in all_variants.items():
    canonical_title = canonical_pages[article_id]["title"]
    canonical_slug = Path(canonical_pages[article_id]["path"]).stem
    for v in variants:
        add_equivalence(v["canonical_key"], canonical_slug)
        filename_key = normalize_title(Path(v["path"]).stem)
        add_equivalence(filename_key, canonical_slug)

print(f"Nombre de cas avec toutes variantes sont des categories : {nb_all_cat}")
print(f"{category_replaced} 'category_*' remplacées par leur version de base")

# --------------------------------------------------
# PASS 3 — resolve redirects
# --------------------------------------------------

def resolve_redirect(key):
    seen = set()
    while key in redirects and key not in seen:
        seen.add(key)
        key = redirects[key]
    return key

for k, v in list(redirects.items()):
    equivalences[k] = resolve_redirect(v)

for src, dst in list(redirects.items()):
    final = equivalences.get(dst, dst)
    equivalences[src] = final

redirects.clear()
# --------------------------------------------------
# PASS 4 — normalisation finale des equivalences
# --------------------------------------------------

valid_titles = {
    data["title"]
    for data in canonical_pages.values()
}

for k, v in list(equivalences.items()):
    if v not in valid_titles:
        equivalences[k] = equivalences.get(v, v)
# category:* ou category_* comme clés
for k, v in list(equivalences.items()):
    new_k = re.sub(r"^category[\s:_]+", "category ", k)
    if new_k != k:
        equivalences[new_k] = v
        del equivalences[k]
# invariant registry
for k, v in equivalences.items():
    if v not in valid_titles:
        problems.append(f"Non canonical mapping: {k} -> {v}")
equivalences = {
    k: v for k, v in equivalences.items()
    if k != v
}
# --------------------------------------------------
# PASS 5 — copie des pages canoniques
# --------------------------------------------------


def title_to_filename(title: str) -> str:
    return sanitize_filename(
        title.replace(" ", "_").casefold() + ".html"
    )


copied = 0
total = len(canonical_pages)

for i, (key, data) in enumerate(canonical_pages.items(), 1):

    src = data["path"]

    dst_name = sanitize_filename(src.name.casefold())
    dst = PAGES_DIR / dst_name

    try:
        shutil.copy2(src, dst)
        canonical_pages[key] = dst_name
        copied += 1
    except Exception as e:
        problems.append(f"Copy failed {src}: {e}")

    if i % 200 == 0 or i == total:
        print(f"{i}/{total} copiés")

print(f"{copied} pages copiées")

# --------------------------------------------------
# SAVE REGISTRY
# --------------------------------------------------

registry = {
    "canonical_pages": canonical_pages,
    "equivalences": equivalences,
    "redirects": redirects,
    "ignored_pages": ignored_pages,
}

REGISTRY_PATH.parent.mkdir(exist_ok=True)
with open(REGISTRY_PATH, "w", encoding="utf-8") as f:
    json.dump(registry, f, indent=2, ensure_ascii=False)

# --------------------------------------------------
# REPORT
# --------------------------------------------------

with open(REPORT_PATH, "w", encoding="utf-8") as f:
    f.write("=== MIGRATION REPORT ===\n")
    f.write(f"Canonical pages: {len(canonical_pages)}\n")
    f.write(f"Equivalences: {len(equivalences)}\n")
    f.write(f"Redirects: {len(redirects)}\n")
    f.write(f"Ignored: {len(ignored_pages)}\n")
    f.write(f"Problems: {len(problems)}\n\n")
    for p in problems[:200]:
        f.write(p + "\n")

print("\n✅ PREPARATION COMPLETE")