"""Parser for EPTM Matu MP grade lists ('Liste de contrôle des notes MP')."""
from __future__ import annotations

import re
from pathlib import Path

import pdfplumber

_RE_HDR = re.compile(
    r"contr.le des notes\s+([\w][\w\-]*\s+[\w][\w\-]*)\s+(\d{2}-\d{2}\s+\d+)",
    re.I,
)


def _to_float(v) -> float | None:
    if v is None:
        return None
    s = str(v).strip().replace(",", ".")
    try:
        return float(s)
    except ValueError:
        return None


def parse_matu_pdf(pdf_path: str | Path) -> dict:
    """Parse an MP grade control list PDF.

    Returns::

        {
            "classe_mp": "MP1-TASV 2A",
            "sem_label": "25-26 2",
            "apprentis": [
                {
                    "nom_complet": str,
                    "moy": float | None,
                    "promotion": str | None,   # "B" / "P" / "NB"
                    "prom_info": str | None,   # "25-26 1" for NB
                },
                ...
            ],
        }
    """
    classe_mp = ""
    sem_label = ""
    apprentis: list[dict] = []

    with pdfplumber.open(pdf_path) as pdf:
        for page in pdf.pages:
            text = page.extract_text() or ""

            if not classe_mp:
                m = _RE_HDR.search(text)
                if m:
                    raw = m.group(1).strip()
                    # Normalize "3-C" → "3C" (some PDFs use a hyphen before the section letter)
                    classe_mp = re.sub(r"(\d)-([A-Za-z])\s*$", r"\1\2", raw)
                    sem_label = re.sub(r"\s+", " ", m.group(2).strip())

            for tbl in page.extract_tables():
                if not tbl or len(tbl) < 4:
                    continue
                # Verify it looks like the grades table (col 3 contains numeric values in data rows)
                found = False
                for row in tbl[2:5]:
                    if row and row[0] and _to_float(row[3] if len(row) > 3 else None) is not None:
                        found = True
                        break
                if not found:
                    continue

                for row in tbl[2:]:  # skip 2 header rows
                    if not row or not row[0]:
                        continue
                    name = str(row[0]).strip()
                    if not name or "Moyenne" in name:
                        continue
                    moy = _to_float(row[3] if len(row) > 3 else None)
                    prom_raw = str(row[6]).strip() if len(row) > 6 and row[6] else ""
                    prom_info_raw = str(row[7]).strip() if len(row) > 7 and row[7] else ""
                    apprentis.append({
                        "nom_complet": name,
                        "moy": moy,
                        "promotion": prom_raw or None,
                        "prom_info": prom_info_raw or None,
                    })

    # Fallback : extract class name from filename if PDF text parsing failed
    if not classe_mp:
        stem = Path(pdf_path).stem  # e.g. "matu_MP1-TASV_3C"
        if stem.startswith("matu_"):
            classe_mp = stem[5:].replace("_", " ")  # "MP1-TASV 3C"

    return {"classe_mp": classe_mp, "sem_label": sem_label, "apprentis": apprentis}