"""Unit tests for `undercooked.sim.recipe` (phase 02 task 02).

The recipe book is the content contract every later phase cooks against: strict
schemas (typos are load errors, not defaults), deterministic helpers, and a
`min_seconds_to_complete` solver bound the validator trusts. Every failing case
here is a YAML an author could plausibly write.
"""

from __future__ import annotations

from pathlib import Path
from typing import Any

import pytest
from pydantic import ValidationError

from undercooked.sim.model import ItemForm, ItemKind, StationKind
from undercooked.sim.recipe import (
    HANDLING_S,
    ContentError,
    Ingredient,
    Recipe,
    RecipeBook,
    Step,
    describe_validation_error,
    load_recipe_book,
    read_yaml_mapping,
)

pytestmark = pytest.mark.unit


def soup_dict(**overrides: Any) -> dict[str, Any]:
    """A minimal valid soup recipe body; overrides replace top-level fields."""
    body: dict[str, Any] = {
        "id": "soup",
        "name": "Tomato Soup",
        "base_score": 40,
        "ingredients": [
            {"kind": "tomato", "form": "raw"},
            {"kind": "onion", "form": "raw", "count": 2},
        ],
        "steps": [
            {"kind": "chop", "station": "chop_board", "seconds": 0.9},
            {"kind": "cook", "station": "stove", "seconds": 5.0},
        ],
    }
    body.update(overrides)
    return body


def book_dict(**overrides: Any) -> dict[str, Any]:
    data: dict[str, Any] = {"recipes": {"soup": soup_dict()}}
    data.update(overrides)
    return data


def write_book(directory: Path, text: str) -> Path:
    path = directory / "recipes.yaml"
    path.write_text(text, encoding="utf-8")
    return path


# --------------------------------------------------------------------- Ingredient / Step


def test_handling_constant_is_the_documented_bound() -> None:
    assert HANDLING_S == 0.6


def test_ingredient_defaults_count_to_one() -> None:
    ingredient = Ingredient(kind=ItemKind.TOMATO, form=ItemForm.RAW)
    assert ingredient.count == 1


def test_ingredient_count_must_be_positive() -> None:
    with pytest.raises(ValidationError, match="count"):
        Ingredient(kind=ItemKind.TOMATO, form=ItemForm.RAW, count=0)


def test_ingredient_kinds_are_the_enum_not_arbitrary_strings() -> None:
    with pytest.raises(ValidationError):
        Ingredient.model_validate({"kind": "durian", "form": "raw"})


def test_step_defaults_to_zero_seconds() -> None:
    step = Step(kind="pick", station=StationKind.SPAWN_SHELF)
    assert step.seconds == 0.0


def test_step_kind_is_a_closed_vocabulary() -> None:
    with pytest.raises(ValidationError, match="kind"):
        Step.model_validate({"kind": "throw", "station": "chop_board"})


def test_step_seconds_cannot_be_negative() -> None:
    with pytest.raises(ValidationError, match="seconds"):
        Step(kind="chop", station=StationKind.CHOP_BOARD, seconds=-0.1)


def test_step_station_must_be_a_known_station_kind() -> None:
    with pytest.raises(ValidationError, match="station"):
        Step.model_validate({"kind": "cook", "station": "deep_fryer"})


# --------------------------------------------------------------------------- Recipe


def test_recipe_happy_path_carries_documented_defaults() -> None:
    recipe = Recipe.model_validate(soup_dict())
    assert recipe.requires_plating is True
    assert recipe.tags == []
    assert [ingredient.count for ingredient in recipe.ingredients] == [1, 2]


def test_recipe_rejects_unknown_keys() -> None:
    with pytest.raises(ValidationError, match=r"extra_forbidden|Extra inputs"):
        Recipe.model_validate(soup_dict(garnish="parsley"))


def test_recipe_requires_ingredients_and_steps() -> None:
    with pytest.raises(ValidationError, match="ingredients"):
        Recipe.model_validate(soup_dict(ingredients=[]))
    with pytest.raises(ValidationError, match="steps"):
        Recipe.model_validate(soup_dict(steps=[]))


def test_recipe_score_and_ids_are_sane() -> None:
    with pytest.raises(ValidationError):
        Recipe.model_validate(soup_dict(base_score=-1))
    with pytest.raises(ValidationError):
        Recipe.model_validate(soup_dict(id=""))


# ------------------------------------------------------------------------ RecipeBook


def test_book_reads_keys_ids_and_the_ingredient_catalog() -> None:
    book = RecipeBook.model_validate(
        book_dict(ingredients=["tomato", "onion", "plate"])
    )
    assert book.ids() == ("soup",)
    assert book.get("soup").base_score == 40
    assert book.ingredients == [ItemKind.TOMATO, ItemKind.ONION, ItemKind.PLATE]


def test_book_ids_follow_declaration_order() -> None:
    book = RecipeBook.model_validate(
        book_dict(recipes={"salad": soup_dict(id="salad"), "soup": soup_dict()})
    )
    assert book.ids() == ("salad", "soup")


def test_book_key_must_equal_the_recipe_id() -> None:
    with pytest.raises(ValidationError, match="keys must equal"):
        RecipeBook.model_validate(book_dict(recipes={"soup": soup_dict(id="chowder")}))


def test_get_unknown_recipe_names_the_known_ones() -> None:
    book = RecipeBook.model_validate(book_dict())
    with pytest.raises(KeyError, match="unknown recipe 'ghost'"):
        book.get("ghost")


def test_required_station_kinds_for_a_two_step_recipe() -> None:
    book = RecipeBook.model_validate(book_dict())
    assert book.required_station_kinds("soup") == frozenset(
        {StationKind.CHOP_BOARD, StationKind.STOVE}
    )


def four_step_book() -> RecipeBook:
    recipe = soup_dict(
        steps=[
            {"kind": "chop", "station": "chop_board", "seconds": 0.9},
            {"kind": "cook", "station": "stove", "seconds": 4.0},
            {"kind": "plate", "station": "prep", "seconds": 1.2},
            {"kind": "serve", "station": "serve"},
        ]
    )
    return RecipeBook.model_validate(book_dict(recipes={"soup": recipe}))


def test_required_station_kinds_for_a_four_step_recipe() -> None:
    assert four_step_book().required_station_kinds("soup") == frozenset(
        {StationKind.CHOP_BOARD, StationKind.STOVE, StationKind.PREP, StationKind.SERVE}
    )


def test_required_item_kinds_adds_a_plate_only_when_plating_is_required() -> None:
    book = RecipeBook.model_validate(book_dict())
    assert book.required_item_kinds("soup") == frozenset(
        {ItemKind.TOMATO, ItemKind.ONION, ItemKind.PLATE}
    )
    unplated = RecipeBook.model_validate(
        book_dict(recipes={"soup": soup_dict(requires_plating=False)})
    )
    assert unplated.required_item_kinds("soup") == frozenset({ItemKind.TOMATO, ItemKind.ONION})


def test_min_seconds_to_complete_is_steps_plus_one_handling_allowance() -> None:
    book = RecipeBook.model_validate(book_dict())
    assert book.min_seconds_to_complete("soup") == pytest.approx(0.9 + 5.0 + HANDLING_S)


def test_min_seconds_grows_with_more_steps() -> None:
    minutes = four_step_book().min_seconds_to_complete("soup")
    assert minutes == pytest.approx(0.9 + 4.0 + 1.2 + 0.0 + HANDLING_S)


@pytest.mark.parametrize(
    "method",
    ["required_station_kinds", "required_item_kinds", "min_seconds_to_complete"],
)
def test_solver_helpers_reject_unknown_recipes(method: str) -> None:
    book = RecipeBook.model_validate(book_dict())
    with pytest.raises(KeyError, match="unknown recipe"):
        getattr(book, method)("ghost")


# ------------------------------------------------------------------- load_recipe_book


def test_load_recipe_book_reads_a_real_yaml_file(tmp_path: Path) -> None:
    path = write_book(
        tmp_path,
        """
        ingredients: [tomato, onion, plate]
        recipes:
          soup:
            id: soup
            name: Tomato Soup
            base_score: 40
            ingredients: [{kind: tomato, form: raw}, {kind: onion, form: raw, count: 2}]
            steps:
              - {kind: chop, station: chop_board, seconds: 0.9}
              - {kind: cook, station: stove, seconds: 5}
        """,
    )
    book = load_recipe_book(path)
    assert book.ids() == ("soup",)
    assert book.ingredients == [ItemKind.TOMATO, ItemKind.ONION, ItemKind.PLATE]


def test_load_recipe_book_reports_every_field_problem(tmp_path: Path) -> None:
    path = write_book(
        tmp_path,
        """
        recipes:
          soup:
            id: soup
            name: Soup
            base_score: not-a-number
            ingredients: [{kind: durian, form: raw}]
            steps: [{kind: throw, station: chop_board}]
        """,
    )
    with pytest.raises(ContentError) as excinfo:
        load_recipe_book(path)
    message = str(excinfo.value)
    assert "base_score" in message
    assert "ingredients.0.kind" in message
    assert "steps.0.kind" in message


def test_load_recipe_book_rejects_unknown_top_level_keys(tmp_path: Path) -> None:
    path = write_book(tmp_path, "recipes: {}\ndesserts: {}\n")
    with pytest.raises(ContentError, match="desserts"):
        load_recipe_book(path)


def test_load_recipe_book_missing_file_is_a_content_error(tmp_path: Path) -> None:
    with pytest.raises(ContentError, match="cannot read content file"):
        load_recipe_book(tmp_path / "nope.yaml")


def test_load_recipe_book_invalid_yaml_is_a_content_error(tmp_path: Path) -> None:
    path = write_book(tmp_path, "recipes: [unclosed\n")
    with pytest.raises(ContentError, match="invalid YAML"):
        load_recipe_book(path)


def test_load_recipe_book_rejects_a_list_document(tmp_path: Path) -> None:
    path = write_book(tmp_path, "- just\n- a\n- list\n")
    with pytest.raises(ContentError, match="expected a YAML mapping"):
        load_recipe_book(path)


def test_empty_file_reads_as_an_empty_mapping_then_fails_the_schema(tmp_path: Path) -> None:
    path = write_book(tmp_path, "")
    assert read_yaml_mapping(path) == {}
    with pytest.raises(ContentError, match="recipes: Field required"):
        load_recipe_book(path)


# ----------------------------------------------------------------- strictness plumbing


def test_assignment_revalidates_so_late_edits_cannot_corrupt_a_model() -> None:
    ingredient = Ingredient(kind=ItemKind.TOMATO, form=ItemForm.RAW)
    ingredient.count = 3
    assert ingredient.count == 3
    with pytest.raises(ValidationError):
        ingredient.count = 0


def test_describe_validation_error_flattens_loc_paths(tmp_path: Path) -> None:
    with pytest.raises(ValidationError) as excinfo:
        RecipeBook.model_validate({})
    described = describe_validation_error(excinfo.value, "book.yaml")
    assert described.startswith("book.yaml: recipes: Field required")