#!/usr/bin/env python3
"""
Regression guard for RATIONAL PORTIONS.

Checks TODAY's meals in meal-history.json (override with --all for the 7-day window)
for:
  1. CAP EXCEEDED — a protein item used in a single meal above its inventory
     `max_per_meal`, or above the fallback cap when no explicit cap exists.
  2. OVERLOAD — a single protein at >=70% of its cap that ALSO supplies >=85% of the
     meal's protein (a "pile of one ingredient", e.g. 10 sausages). A balanced plate
     where the lead protein is capped but other proteins/veg contribute is NOT flagged.

Units are normalised to grams so items logged in different units (cheese in g vs
inventory's "small block") compare correctly.

Exits non-zero (prints violations) if any rule is broken.
"""
import json, sys, os, argparse
from datetime import datetime, timedelta

SKILL_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
HISTORY = os.path.join(SKILL_DIR, "meal-history.json")
INV = os.path.join(SKILL_DIR, "inventory.json")

# protein (g) per unit, for the dominance estimate
PROTEIN_G = {
    "egg": 6, "sausage": 11, "mince": 0.18, "lentil": 0.24, "tofu": 0.12,
    "tempeh": 0.19, "bean": 9, "whey": 0.8, "cheese": 0.25, "halloumi": 0.21,
    "tuna": 25, "salmon": 25, "mackerel": 20, "chicken": 0.31, "turkey": 0.29,
    "prawn": 0.24, "yogurt": 0.10, "yoghurt": 0.10, "fish": 25,
}

# grams per inventory unit, for converting a stored cap to grams
GRAMS_PER_UNIT = {
    "g": 1, "ml": 1, "kg": 1000, "count": 1, "can": 1,
    "small block": 120, "block": 120, "serving": 1, "portion": 1,
    "pack": 1, "jar": 1, "tub": 1, "bulb": 1, "bottle": 1, "loaf": 1,
}

PROTEIN_CATS = {"protein", "dairy"}


def cap_grams(name, unit, inv):
    it = next((i for i in inv["items"] if i["name"].lower() == name.lower()), None)
    if it and "max_per_meal" in it:
        gpu = GRAMS_PER_UNIT.get(it.get("unit", unit), 1)
        return it["max_per_meal"] * gpu
    rp = inv.get("diet", {}).get("rational_portions", {})
    defaults = rp.get("default_caps", {})
    for kw, cap in defaults.items():
        if kw in name.lower():
            gpu = GRAMS_PER_UNIT.get(rp.get("unit_fallback_unit", unit), 1)
            return cap * gpu
    fb = rp.get("unit_fallback", {}).get(unit, 6)
    return fb * GRAMS_PER_UNIT.get(unit, 1)


def est_protein_g(name, qty, unit):
    per = PROTEIN_G.get(name.lower())
    if per is None:
        for kw, v in PROTEIN_G.items():
            if kw in name.lower():
                per = v
                break
    if per is None:
        return 0.0
    gpu = GRAMS_PER_UNIT.get(unit, 1)
    base = qty * gpu  # grams of food
    # per is g protein per g of food for g/ml units; per-unit for count/can
    if unit in ("g", "ml", "kg"):
        return per * base
    return per * qty


def main():
    ap = argparse.ArgumentParser()
    ap.add_argument("--all", action="store_true", help="check full 7-day window")
    args = ap.parse_args()
    inv = json.load(open(INV))
    hist = json.load(open(HISTORY))
    entries = hist if isinstance(hist, list) else hist.get("entries", [])
    today = datetime.now().strftime("%Y-%m-%d")
    cutoff = datetime.now() - timedelta(days=7)
    violations = []
    for e in entries:
        try:
            d = datetime.strptime(e["date"], "%Y-%m-%d")
        except Exception:
            continue
        if args.all:
            if d < cutoff:
                continue
        else:
            if e["date"] != today:
                continue
        meal_items = e.get("items", [])
        # 1) cap check
        for it in meal_items:
            cap = cap_grams(it["name"], it.get("unit", "count"), inv)
            used = est_protein_g(it["name"], it["qty"], it.get("unit", "count"))
            # compare the RAW quantity against the cap's raw quantity (both in same unit)
            cap_raw = cap / GRAMS_PER_UNIT.get(it.get("unit", "count"), 1) if it.get("unit") in ("g", "ml", "kg") else cap
            # simpler: compare grams of food used vs grams of cap
            food_g = it["qty"] * GRAMS_PER_UNIT.get(it.get("unit", "count"), 1)
            cap_food_g = cap
            if food_g > cap_food_g + 1e-6:
                violations.append(
                    f"CAP EXCEEDED {e['date']} {e['meal']} '{e['name']}': "
                    f"{it['name']} {it['qty']} {it.get('unit','')} exceeds cap "
                    f"~{cap_food_g:.0f} g ({it.get('unit','')})")
        # 2) overload check (single protein >=70% cap AND >=85% of meal protein)
        prot = [(it, cap_grams(it["name"], it.get("unit", "count"), inv),
                 est_protein_g(it["name"], it["qty"], it.get("unit", "count")))
                for it in meal_items]
        total = sum(p for _, _, p in prot) or 1
        for it, cap, pg in prot:
            food_g = it["qty"] * GRAMS_PER_UNIT.get(it.get("unit", "count"), 1)
            if cap and food_g > 0.7 * cap and pg > 0.85 * total:
                violations.append(
                    f"OVERLOAD {e['date']} {e['meal']} '{e['name']}': "
                    f"{it['name']} {it['qty']} is >=70% of its cap and supplies "
                    f"{pg:.0f}/{total:.0f} g ({pg/total*100:.0f}%) of meal protein "
                    f"— not a balanced plate")
    if violations:
        print("FAIL: rational-portion violations:")
        for v in violations:
            print("  -", v)
        sys.exit(1)
    scope = "all logged meals (7d)" if args.all else f"today ({today})"
    print(f"PASS: portions rational — no overload ({scope}).")


if __name__ == "__main__":
    main()