#!/usr/bin/env python3
"""Pick this week's world cuisine for the weekly shop.

Design goals:
- RANDOM per week, but STABLE within a week (seeded by the week's Monday date)
  so that re-runs / retries of the Monday job never flip the cuisine mid-week.
- VARIED over time: the last few chosen cuisines are excluded from the pool.
- PERSISTED to cuisine-rotation.json so the daily meal job can read the active
  cuisine and cook on-theme meals from the same week's buys.

Usage:
  python3 pick_cuisine.py            # pick (or reuse) and persist
  python3 pick_cuisine.py --dry-run  # print only, do not write
Prints a JSON line:
  {"week_monday": "...", "cuisine": "...", "theme_items": [...], "reused": bool}
"""
import argparse
import json
import os
from datetime import date, timedelta

HERE = os.path.dirname(os.path.abspath(__file__))
ROTATION_FILE = os.path.join(HERE, "..", "cuisine-rotation.json")

# Curated cuisines: all are achievable at Lidl on a ~£30 budget, high-protein,
# and contain NO red meat by design. theme_items are cheap, cuisine-appropriate
# buys (proteins/veg/staples/condiments) that add variety; some may already be
# in inventory — the weekly job still cross-checks budget + Lidl availability.
CUISINES = {
    "Mexican / Tex-Mex": [
        "wholemeal tortilla wraps", "tinned black beans", "tinned sweetcorn",
        "tinned chopped tomatoes", "cheddar cheese", "lime", "cumin",
        "smoked paprika", "avocado", "chicken breast", "Greek yogurt",
    ],
    "Greek / Mediterranean": [
        "feta", "Kalamata olives", "cucumber", "cherry tomatoes",
        "chickpeas", "halloumi", "dried oregano", "lemon", "red onion",
        "tinned tuna", "Greek yogurt",
    ],
    "Indian / South Asian": [
        "red lentils", "chickpeas", "tinned tomatoes", "fresh spinach",
        "curry powder", "grated ginger", "onions", "Greek yogurt",
        "firm tofu", "microwave rice", "chicken breast",
    ],    "Thai": [
        "jasmine rice", "coconut milk (tin)", "soy sauce", "lime",
        "grated ginger", "red curry paste", "frozen prawns", "edamame",
        "fish-free: tofu", "fresh coriander", "eggs",
    ],
    "East Asian / Japanese": [
        "egg noodles", "soy sauce", "edamame (frozen)", "eggs",
        "firm tofu", "sesame seeds", "tinned tuna", "miso paste",
        "frozen mixed veg", "grated ginger", "spring onions",
    ],
    "Middle Eastern / Levantine": [
        "chickpeas", "red lentils", "feta", "cucumber", "tomatoes",
        "lemon", "cumin", "pitta breads", "halloumi", "Greek yogurt",
        "fresh parsley", "chicken breast",
    ],
    "Italian": [
        "passata", "wholemeal pasta", "mozzarella", "tinned tuna",
        "cherry tomatoes", "fresh basil", "black olives", "spinach",
        "eggs", "chicken breast", "parmesan",
    ],
    "Korean": [
        "jasmine rice", "soy sauce", "sesame oil", "sesame seeds",
        "gochujang (tube)", "eggs", "firm tofu", "kimchi (jar)",
        "frozen mixed veg", "grated ginger", "spring onions",
    ],
}

# How many recent cuisines to exclude so weeks don't repeat back-to-back.
RECENT_WINDOW = 4


def week_monday(d=None):
    d = d or date.today()
    return d - timedelta(days=d.weekday())  # Monday=0


def load_rotation():
    try:
        with open(ROTATION_FILE) as f:
            return json.load(f)
    except FileNotFoundError:
        return {"current": None, "history": []}


def save_rotation(data):
    os.makedirs(os.path.dirname(ROTATION_FILE), exist_ok=True)
    with open(ROTATION_FILE, "w") as f:
        json.dump(data, f, indent=2)


def pick(dry_run=False):
    import random
    monday = week_monday()
    monday_str = monday.isoformat()
    rot = load_rotation()

    # Same week -> reuse the locked-in cuisine (stable within the week).
    if rot.get("current") and rot["current"].get("week_monday") == monday_str:
        rot["current"]["reused"] = True
        print(json.dumps(rot["current"]))
        return

    pool = list(CUISINES.keys())
    recent = [h["cuisine"] for h in rot.get("history", [])[-RECENT_WINDOW:]]
    candidates = [c for c in pool if c not in recent] or pool

    # Seed by the week's Monday so the pick is deterministic for that week
    # (re-runs in the same week always return the same cuisine).
    rng = random.Random(monday_str)
    cuisine = rng.choice(candidates)

    chosen = {
        "week_monday": monday_str,
        "cuisine": cuisine,
        "theme_items": CUISINES[cuisine],
        "reused": False,
    }

    if dry_run:
        print(json.dumps(chosen))
        return

    history = rot.get("history", [])
    history.append({"week_monday": monday_str, "cuisine": cuisine})
    # Keep history bounded.
    history = history[-12:]
    save_rotation({"current": chosen, "history": history})
    print(json.dumps(chosen))


def main():
    ap = argparse.ArgumentParser()
    ap.add_argument("--dry-run", action="store_true",
                    help="print the pick without persisting")
    args = ap.parse_args()
    pick(dry_run=args.dry_run)


if __name__ == "__main__":
    main()