# -*- coding: utf-8 -*-
"""
Mesin pengukuran ketercapaian CPL/CPMK (inti OBE).

Kebijakan (RANCANGAN.md §7, disepakati 13 Jul 2026):
- Nilai dicatat per mahasiswa per Sub-CPMK (mengikuti format contoh portofolio);
  mode 'agregat' (rata-rata kelas per Sub-CPMK) diperbolehkan tapi ditandai.
- Roll-up dalam MK : Sub-CPMK → CPMK → CPL, rata-rata sederhana (bagi rata).
- Roll-up prodi    : CPMK prodi = rata-rata lintas MK pengukurnya;
                     CPL = rata-rata CPMK pendukungnya. Opsi tertimbang SKS
                     tersedia via pengaturan 'metode_antar_mk' = 'sks'
                     (butuh data SKS; tanpa data SKS jatuh ke bagi rata).
- % kelulusan = persentase mahasiswa dengan skor ≥ ambang (hanya mode
  per-mahasiswa; mode agregat tidak menghasilkan % kelulusan).
"""
import statistics

from . import db


def _rata(xs):
    xs = [x for x in xs if x is not None]
    return sum(xs) / len(xs) if xs else None


def parse_skala(teks: str) -> list[dict]:
    """'A+|91|100|4.00' per baris → [{'huruf','lo','hi','angka'}] terurut turun."""
    out = []
    for line in (teks or "").splitlines():
        bag = [b.strip() for b in line.split("|")]
        if len(bag) >= 3:
            try:
                out.append({
                    "huruf": bag[0], "lo": float(bag[1]), "hi": float(bag[2]),
                    "angka": float(bag[3]) if len(bag) > 3 else None,
                })
            except ValueError:
                continue
    return sorted(out, key=lambda s: -s["lo"])


def huruf_mutu(skor: float, skala: list[dict]) -> str:
    for s in skala:
        if s["lo"] <= skor <= s["hi"]:
            return s["huruf"]
    return "?"


def skor_sub(nilai_data: dict, ambang: float) -> dict:
    """Skor per Sub-CPMK dari data nilai tersimpan.

    nilai_data = {"mode": "per_mahasiswa"|"agregat",
                  "mahasiswa": [{"nim","nama","skor":{sub: nilai}}] |
                  "agregat": {sub: rata}}
    → {sub: {"rata": x, "n": jumlah_mhs, "lulus_pct": y|None}}
    """
    out = {}
    if nilai_data.get("mode") == "per_mahasiswa":
        per_sub: dict[str, list[float]] = {}
        for m in nilai_data.get("mahasiswa", []):
            for sub, v in (m.get("skor") or {}).items():
                if v is not None:
                    per_sub.setdefault(sub, []).append(float(v))
        for sub, xs in per_sub.items():
            out[sub] = {
                "rata": _rata(xs),
                "n": len(xs),
                "lulus_pct": 100.0 * sum(1 for x in xs if x >= ambang) / len(xs),
            }
    else:
        for sub, v in (nilai_data.get("agregat") or {}).items():
            if v in (None, ""):
                continue
            out[sub] = {"rata": float(v), "n": None, "lulus_pct": None}
    return out


def bobot_sub_dari_rps(rps_data: dict | None) -> dict[str, float]:
    """Bobot (%) tiap Sub-CPMK = jumlah porsi bagi-rata dari komponen RPS (kisi-kisi)."""
    bobot: dict[str, float] = {}
    if not rps_data:
        return bobot
    for k in rps_data.get("komponen", []):
        subs = k.get("subs", [])
        try:
            b = float(k.get("bobot") or 0)
        except (TypeError, ValueError):
            continue
        for s in subs:
            bobot[s] = bobot.get(s, 0.0) + b / len(subs)
    return bobot


def skor_dari_sesi(komponen_daftar: list[dict], sesi: dict) -> dict[str, dict[str, float]]:
    """nim -> {sub: skor}, dihitung dari log sesi input per-komponen (tombol
    'isi per komponen' di halaman nilai): rata sederhana antar sesi dalam
    komponen yang sama (mis. beberapa kali Kuis), lalu rata tertimbang bobot
    antar-komponen bila satu Sub-CPMK diukur oleh >1 komponen (mis. Kuis dan
    Presentasi sama-sama menilai satu Sub-CPMK) — bobot mengikuti alokasi
    yang sama dengan bobot_sub_dari_rps (bobot komponen dibagi rata ke subnya).
    """
    komponen_by_i = {k["i"]: k for k in komponen_daftar}
    per_komponen_avg: dict[int, dict[str, float]] = {}
    for i_str, daftar_sesi in (sesi or {}).items():
        try:
            i = int(i_str)
        except (TypeError, ValueError):
            continue
        if i not in komponen_by_i or not daftar_sesi:
            continue
        per_nim: dict[str, list[float]] = {}
        for s in daftar_sesi:
            for nim, v in (s.get("nilai") or {}).items():
                if v is not None:
                    per_nim.setdefault(nim, []).append(float(v))
        per_komponen_avg[i] = {nim: _rata(xs) for nim, xs in per_nim.items()}

    kontribusi_per_sub: dict[str, list[tuple[float, dict]]] = {}
    for i, avg_map in per_komponen_avg.items():
        k = komponen_by_i[i]
        try:
            bobot = float(k.get("bobot") or 0)
        except (TypeError, ValueError):
            bobot = 0
        n_subs = len(k["subs"]) or 1
        w = bobot / n_subs if bobot else 1.0
        for sub in k["subs"]:
            kontribusi_per_sub.setdefault(sub, []).append((w, avg_map))

    out: dict[str, dict[str, float]] = {}
    for sub, kontribusi in kontribusi_per_sub.items():
        nims: set[str] = set()
        for _, avg_map in kontribusi:
            nims |= avg_map.keys()
        for nim in nims:
            pasangan = [(w, avg_map[nim]) for w, avg_map in kontribusi if nim in avg_map]
            total_w = sum(w for w, _ in pasangan)
            nilai = (sum(w * v for w, v in pasangan) / total_w) if total_w \
                else _rata([v for _, v in pasangan])
            out.setdefault(nim, {})[sub] = nilai
    return out


def nilai_akhir_mahasiswa(nilai_data: dict, bobot_sub: dict[str, float]) -> list[dict]:
    """Nilai akhir tertimbang bobot Sub-CPMK per mahasiswa (mode per_mahasiswa)."""
    out = []
    for m in nilai_data.get("mahasiswa", []):
        skor = m.get("skor") or {}
        pasangan = [(bobot_sub.get(s), v) for s, v in skor.items() if v is not None]
        berbobot = [(b, v) for b, v in pasangan if b]
        if berbobot:
            total_b = sum(b for b, _ in berbobot)
            akhir = sum(b * v for b, v in berbobot) / total_b
        else:  # RPS belum mengisi bobot → rata-rata sederhana
            akhir = _rata([v for _, v in pasangan])
        if akhir is not None:
            out.append({"nim": m.get("nim", ""), "nama": m.get("nama", ""),
                        "akhir": akhir})
    return out


def statistik_akhir(akhir: list[dict], skala: list[dict]) -> dict | None:
    xs = [a["akhir"] for a in akhir]
    if not xs:
        return None
    frek = {s["huruf"]: 0 for s in skala}
    for x in xs:
        h = huruf_mutu(x, skala)
        frek[h] = frek.get(h, 0) + 1
    return {
        "n": len(xs),
        "mean": statistics.mean(xs),
        "median": statistics.median(xs),
        "stdev": statistics.stdev(xs) if len(xs) > 1 else 0.0,
        "min": min(xs),
        "max": max(xs),
        "range": max(xs) - min(xs),
        "frekuensi": frek,
    }


def rollup_mk(peta: dict, nilai_data: dict, ambang: float) -> dict:
    """Ketercapaian satu MK: per Sub-CPMK → CPMK → CPL (bagi rata)."""
    sub = skor_sub(nilai_data, ambang)

    cpmk: dict[str, dict] = {}
    for c in peta["cpmks"]:
        skor = _rata([sub[s["kode"]]["rata"] for s in c["subs"] if s["kode"] in sub])
        n_ternilai = sum(1 for s in c["subs"] if s["kode"] in sub)
        cpmk[c["kode"]] = {"skor": skor, "cpl": c["cpl"],
                           "n_sub": len(c["subs"]), "n_ternilai": n_ternilai}

    cpl: dict[str, dict] = {}
    for cp in peta["cpls"]:
        skor = _rata([v["skor"] for v in cpmk.values()
                      if cp["kode"] in v["cpl"] and v["skor"] is not None])
        cpl[cp["kode"]] = {"skor": skor}

    return {"sub": sub, "cpmk": cpmk, "cpl": cpl,
            "mode": nilai_data.get("mode", "agregat")}


def rollup_prodi(tahun: str | None = None) -> dict:
    """Ketercapaian tingkat prodi + kelengkapan bukti per CPL/CPMK."""
    tahun = tahun or db.tahun_aktif()
    pengaturan = db.ambil_pengaturan()
    ambang = float(pengaturan["ambang"])
    pakai_sks = pengaturan.get("metode_antar_mk") == "sks"
    sks = db.sks_mk() if pakai_sks else {}
    k = db.kurikulum()
    semua = db.semua_nilai(tahun)

    def rata_antar_mk(entri):
        """Skor CPMK lintas MK: bagi rata, atau tertimbang SKS bila diatur."""
        if not entri:
            return None
        if pakai_sks and sks:
            bobot = [(float(sks.get(mk, {}).get("sks") or 0), s) for mk, s, _ in entri]
            total = sum(b for b, _ in bobot if b)
            if total:
                return sum(b * s for b, s in bobot if b) / total
        return _rata([s for _, s, _ in entri])

    # skor CPMK per MK
    per_cpmk: dict[str, list[tuple[str, float, str]]] = {}  # key cpmk → [(mk, skor, mode)]
    for mk_kode, nilai_data in semua.items():
        peta = db.peta_mk(mk_kode)
        if not peta:
            continue
        hasil = rollup_mk(peta, nilai_data, ambang)
        for kode_cpmk, v in hasil["cpmk"].items():
            if v["skor"] is not None:
                per_cpmk.setdefault(kode_cpmk, []).append(
                    (mk_kode, v["skor"], hasil["mode"])
                )

    # CPMK prodi = bagi rata lintas MK pengukur; kelengkapan = pengukur/pemikul
    cpmk_prodi: dict[str, dict] = {}
    for ckey, info in k["cpmk"].items():
        kode = info.get("kode", ckey)
        pemikul = info.get("mk", [])
        entri = per_cpmk.get(kode, [])
        cpmk_prodi[kode] = {
            "kode": kode,
            "cpl": info.get("cpl", []),
            "skor": rata_antar_mk(entri),
            "n_pemikul": len(pemikul),
            "n_setor": len(entri),
            "ada_agregat": any(m == "agregat" for _, _, m in entri),
            "mk_terlemah": min(entri, key=lambda e: e[1])[:2] if entri else None,
        }

    # CPL = bagi rata CPMK pendukung
    cpl_prodi: dict[str, dict] = {}
    for kode_cpl, info in k["cpl"].items():
        pendukung = [c for c in cpmk_prodi.values() if kode_cpl in c["cpl"]]
        ternilai = [c for c in pendukung if c["skor"] is not None]
        skor = _rata([c["skor"] for c in ternilai])
        terlemah = min(ternilai, key=lambda c: c["skor"]) if ternilai else None
        cpl_prodi[kode_cpl] = {
            "kode": kode_cpl,
            "desk": info["desk"],
            "skor": skor,
            "tercapai": (skor is not None and skor >= ambang),
            "n_cpmk": len(pendukung),
            "n_cpmk_ternilai": len(ternilai),
            "n_mk_pemikul": sum(c["n_pemikul"] for c in pendukung),
            "n_mk_setor": sum(c["n_setor"] for c in pendukung),
            "ada_agregat": any(c["ada_agregat"] for c in ternilai),
            "cpmk_terlemah": terlemah["kode"] if terlemah else None,
            "mk_terlemah": (terlemah["mk_terlemah"] if terlemah else None),
        }

    return {"cpl": cpl_prodi, "cpmk": cpmk_prodi, "ambang": ambang,
            "n_mk_setor": len(semua), "tahun": tahun,
            "metode": "sks" if (pakai_sks and sks) else "rata"}