"""Recipe helper functions for the Family Wall recipe box.

Verified endpoints (2026-04-16 via FW_DEBUG=1):
  - Create: POST mprecipeput — params use 'recipe.' prefix (recipe.name, etc.)
  - Update: POST mprecipeput with recipe.metaId — same prefix convention
  - Read all: POST metasync with id='recipe' — response at a00.r.r.updatedCreated[]
  - Delete: POST metadelete with id=<recipe_metaId>

Newline normalisation (bug fix v0.6.1):
  LLM tool calls may pass literal backslash-n ('\\n', two chars) instead of a
  real newline character.  _normalize_newlines() converts them before sending
  to the API so the server splits ingredients/instructions correctly.
"""

from __future__ import annotations

from typing import Any


def _normalize_newlines(text: str) -> str:
    """Replace literal backslash-n sequences with real newline characters.

    When an LLM generates a tool call it may produce ``"line1\\nline2"``
    (two chars: backslash + n) instead of ``"line1\\nline2"`` (real newline).
    The Family Wall API splits ingredients and instructions on real newlines
    only, so we normalise before sending.

    Args:
        text: Free-text string that may contain literal ``\\n`` sequences.

    Returns:
        The same string with every ``\\n`` replaced by a real ``\\n``.
    """
    return text.replace("\\n", "\n")


def parse_recipe_summary(raw: dict[str, Any]) -> dict[str, Any]:
    """Extract a compact recipe summary from a raw API recipe object.

    Args:
        raw: Raw recipe dict from the API (metasync or mprecipeput response).

    Returns:
        Dict with keys: id, name, prep_time_minutes, cook_time_minutes, serves,
        description, can_delete.
    """
    prep = raw.get("prepTime")
    cook = raw.get("cookTime")
    srv = raw.get("serves")
    return {
        "id": raw.get("metaId"),
        "name": raw.get("name"),
        "description": raw.get("description") or None,
        "prep_time_minutes": int(prep) if prep else None,
        "cook_time_minutes": int(cook) if cook else None,
        "serves": int(srv) if srv else None,
        "can_delete": raw.get("rights", {}).get("canDelete") == "true",
    }


def parse_recipe_full(raw: dict[str, Any]) -> dict[str, Any]:
    """Extract the full recipe from a raw API recipe object.

    Args:
        raw: Raw recipe dict from the API (metasync or mprecipeput response).

    Returns:
        Dict with all recipe fields including ingredients, instructions, etc.
    """
    prep = raw.get("prepTime")
    cook = raw.get("cookTime")
    srv = raw.get("serves")

    # ingredientsList is auto-parsed by the server; normalise to a plain list of names.
    ingredients_list_raw: list[dict[str, Any]] = raw.get("ingredientsList") or []
    ingredients_parsed = [item.get("name") for item in ingredients_list_raw if item.get("name")]

    # Extract recipe categories from API response.
    # The API provides both recipeCategoryIdList (actual IDs) and recipeCategories
    # (system name strings). We use the ID list as the authoritative source.
    categories: list[str] = []
    category_ids: list[str] = raw.get("recipeCategoryIdList") or []
    for cat_id in category_ids:
        if cat_id:
            categories.append(cat_id)

    return {
        "id": raw.get("metaId"),
        "name": raw.get("name"),
        "description": raw.get("description") or None,
        "ingredients": raw.get("ingredients") or None,
        "ingredients_parsed": ingredients_parsed,
        "instructions": raw.get("instructions") or None,
        "prep_time_minutes": int(prep) if prep else None,
        "cook_time_minutes": int(cook) if cook else None,
        "serves": int(srv) if srv else None,
        "url": raw.get("url") or None,
        "is_favorite": raw.get("isFavorite") == "true",
        "can_delete": raw.get("rights", {}).get("canDelete") == "true",
        "can_update": raw.get("rights", {}).get("canUpdate") == "true",
        "created_at": raw.get("creationDate"),
        "account_id": raw.get("accountId"),
        "category_ids": categories,
    }


def build_create_params(
    name: str,
    description: str | None = None,
    ingredients: str | None = None,
    instructions: str | None = None,
    prep_time_minutes: int | None = None,
    cook_time_minutes: int | None = None,
    serves: int | None = None,
    url: str | None = None,
    category_ids: list[str] | None = None,
) -> dict[str, str | list[str]]:
    """Build the form parameters for a mprecipeput create call.

    The Family Wall API requires the 'recipe.' prefix for all recipe fields.
    isRecipe='true' is always required.

    Newline normalisation is applied to ingredients and instructions so that
    literal ``\\n`` sequences sent by an LLM are converted to real newlines,
    which the server uses to split the ingredient list.

    Args:
        name: Recipe title (required).
        description: Optional description.
        ingredients: Optional free-text ingredients, lines separated by ``\\n``.
            Literal backslash-n sequences are normalised to real newlines.
        instructions: Optional free-text cooking instructions, lines separated
            by ``\\n``.  Literal backslash-n sequences are normalised.
        prep_time_minutes: Optional preparation time in minutes.
        cook_time_minutes: Optional cooking time in minutes.
        serves: Optional number of servings.
        url: Optional external URL (e.g. original recipe source).
        category_ids: Optional list of recipe category IDs
            (e.g. ``["category/23431854_2"]``).

    Returns:
        Dict of form parameters ready to send to mprecipeput.
    """
    params: dict[str, str | list[str]] = {
        "recipe.name": name,
        "recipe.isRecipe": "true",
    }
    if description is not None:
        params["recipe.description"] = description
    if ingredients is not None:
        params["recipe.ingredients"] = _normalize_newlines(ingredients)
    if instructions is not None:
        params["recipe.instructions"] = _normalize_newlines(instructions)
    if prep_time_minutes is not None:
        params["recipe.prepTime"] = str(prep_time_minutes)
    if cook_time_minutes is not None:
        params["recipe.cookTime"] = str(cook_time_minutes)
    if serves is not None:
        params["recipe.serves"] = str(serves)
    if url is not None:
        params["recipe.url"] = url
    if category_ids is not None:
        params["recipe.recipeCategoryIdList"] = category_ids
    return params


def build_update_params(
    recipe_id: str,
    current_name: str,
    name: str | None = None,
    description: str | None = None,
    ingredients: str | None = None,
    instructions: str | None = None,
    prep_time_minutes: int | None = None,
    cook_time_minutes: int | None = None,
    serves: int | None = None,
    url: str | None = None,
    category_ids: list[str] | None = None,
) -> dict[str, str | list[str]]:
    """Build the form parameters for a mprecipeput update call.

    Identical to :func:`build_create_params` except that ``recipe.metaId`` is
    included so the API updates the existing recipe instead of creating a new one.
    ``recipe.name`` and ``recipe.isRecipe`` are always present — the name falls
    back to *current_name* when the caller does not provide a new one.

    Newline normalisation is applied to ingredients and instructions (see
    :func:`_normalize_newlines`).

    Args:
        recipe_id: metaId of the recipe to update (e.g. ``"recipe/123_456"``).
        current_name: The recipe's existing name, used as fallback when *name*
            is not provided.  Fetched from the API before calling this function.
        name: New recipe title (omit to keep existing).
        description: New description (omit to keep existing).
        ingredients: New ingredients text (omit to keep existing).
        instructions: New instructions text (omit to keep existing).
        prep_time_minutes: New preparation time in minutes (omit to keep existing).
        cook_time_minutes: New cooking time in minutes (omit to keep existing).
        serves: New number of servings (omit to keep existing).
        url: New external URL (omit to keep existing).
        category_ids: New list of recipe category IDs (omit to keep existing).
            Pass empty list to remove all categories.

    Returns:
        Dict of form parameters ready to send to mprecipeput.
    """
    params: dict[str, str | list[str]] = {
        "recipe.metaId": recipe_id,
        "recipe.name": name if name is not None else current_name,
        "recipe.isRecipe": "true",
    }
    if description is not None:
        params["recipe.description"] = description
    if ingredients is not None:
        params["recipe.ingredients"] = _normalize_newlines(ingredients)
    if instructions is not None:
        params["recipe.instructions"] = _normalize_newlines(instructions)
    if prep_time_minutes is not None:
        params["recipe.prepTime"] = str(prep_time_minutes)
    if cook_time_minutes is not None:
        params["recipe.cookTime"] = str(cook_time_minutes)
    if serves is not None:
        params["recipe.serves"] = str(serves)
    if url is not None:
        params["recipe.url"] = url
    if category_ids is not None:
        params["recipe.recipeCategoryIdList"] = category_ids
    return params