"""Business logic: compute worked hours and expected hours per day/week."""
from datetime import datetime, timedelta


def hhmm_to_minutes(val: str | None) -> int:
    if not val:
        return 0
    h, m = val.split(":")
    return int(h) * 60 + int(m)


def minutes_to_hhmm(minutes: int) -> str:
    sign = "-" if minutes < 0 else ""
    minutes = abs(minutes)
    return f"{sign}{minutes // 60}h{minutes % 60:02d}"


def heures_travaillees(p: dict) -> int:
    """Return worked minutes for a pointage row."""
    matin = max(0, hhmm_to_minutes(p["matin_sortie"]) - hhmm_to_minutes(p["matin_entree"]))
    aprem = max(0, hhmm_to_minutes(p["aprem_sortie"]) - hhmm_to_minutes(p["aprem_entree"]))
    # only count if entry AND exit are present
    if not (p["matin_entree"] and p["matin_sortie"]):
        matin = 0
    if not (p["aprem_entree"] and p["aprem_sortie"]):
        aprem = 0
    return matin + aprem


def heures_dues(date_str: str, conges: list[dict], heures_jour_min: int) -> int:
    """Return expected minutes for a date, accounting for vacations."""
    d = datetime.strptime(date_str, "%Y-%m-%d").date()
    # Weekend = no hours due
    if d.weekday() >= 5:
        return 0

    conges_date = {c["type"] for c in conges if c["date"] == date_str}

    if "jour" in conges_date:
        return 0
    if "matin" in conges_date and "aprem" in conges_date:
        return 0

    half = heures_jour_min // 2
    if "matin" in conges_date or "aprem" in conges_date:
        return half

    return heures_jour_min


def compute_week(pointages: list[dict], conges: list[dict], heures_jour_min: int) -> dict:
    """Compute totals for a list of pointages (one week)."""
    total_travaille = 0
    total_du = 0
    jours = []

    for p in pointages:
        travaille = heures_travaillees(p)
        du = heures_dues(p["date"], conges, heures_jour_min)
        delta = travaille - du
        total_travaille += travaille
        total_du += du
        jours.append({
            **p,
            "travaille_min": travaille,
            "du_min": du,
            "delta_min": delta,
            "travaille": minutes_to_hhmm(travaille),
            "du": minutes_to_hhmm(du),
            "delta": minutes_to_hhmm(delta),
            "conge": {c["type"] for c in conges if c["date"] == p["date"]},
        })

    # Mark each day as complete (all non-congé slots filled, or day is a congé/weekend)
    for jour in jours:
        cg = jour["conge"]
        matin_done = bool(jour.get("matin_entree") and jour.get("matin_sortie")) or "matin" in cg or "jour" in cg
        aprem_done = bool(jour.get("aprem_entree") and jour.get("aprem_sortie")) or "aprem" in cg or "jour" in cg
        jour["is_complete"] = (jour["du_min"] == 0) or (matin_done and aprem_done)

    # Cumulative weekly delta — accumulated for all days, but visible only when chain is unbroken
    cumul = 0
    cumul_chain_ok = True
    for jour in jours:
        cumul += jour["delta_min"]
        jour["delta_cumul_min"] = cumul
        jour["delta_cumul"] = minutes_to_hhmm(abs(cumul))
        # Chain breaks on the first incomplete workday — subsequent days don't show cumul
        if not jour["is_complete"] and jour["du_min"] > 0:
            cumul_chain_ok = False
        jour["cumul_visible"] = jour["is_complete"] and cumul_chain_ok

    # Sortie cible: optimal aprem exit so the week totals exactly the target hours
    worked_before = 0
    for i, jour in enumerate(jours):
        cg = jour["conge"]
        if jour["du_min"] == 0 or "aprem" in cg or "jour" in cg:
            jour["sortie_cible"] = None
            worked_before += jour["travaille_min"]
            continue

        du_remaining = sum(j["du_min"] for j in jours[i + 1:])
        needed_today = max(0, total_du - worked_before - du_remaining)

        worked_morning = 0
        if jour.get("matin_entree") and jour.get("matin_sortie"):
            worked_morning = max(0, hhmm_to_minutes(jour["matin_sortie"]) - hhmm_to_minutes(jour["matin_entree"]))

        needed_aprem = max(0, needed_today - worked_morning)
        aprem_start = hhmm_to_minutes(jour["aprem_entree"]) if jour.get("aprem_entree") else 14 * 60
        sortie_min = max(aprem_start + needed_aprem, 17 * 60)

        if sortie_min > 23 * 60 + 59:
            jour["sortie_cible"] = None  # deficit too large to recover in one afternoon
        else:
            jour["sortie_cible"] = f"{sortie_min // 60:02d}:{sortie_min % 60:02d}"
        worked_before += jour["travaille_min"]

    return {
        "jours": jours,
        "total_travaille": minutes_to_hhmm(total_travaille),
        "total_du": minutes_to_hhmm(total_du),
        "solde": minutes_to_hhmm(total_travaille - total_du),
        "solde_min": total_travaille - total_du,
    }