import {
  type BrowsableSourceItemView,
  type DietView,
  ErrorCode,
  type IngredientView,
  type Meal,
  type PlanningItemView,
  type RecipeSummaryView,
  type RecipeView,
  type WeekDay,
} from "@batch-cooking/shared";
import { useEffect, useState } from "react";
import { useTranslation } from "react-i18next";
import { useNavigate } from "react-router-dom";
import { ApiError, apiClient } from "../../api/client";
import { CheckboxOption } from "../../components/ui/Checkbox";
import { Dialog } from "../../components/ui/Dialog";
import { errorMessageService } from "../../services/error-message.service";
import { DietTagSelect } from "../recipes/DietTagSelect";
import { IngredientPicker } from "../recipes/IngredientPicker";
import { RecipeSourcesPanel } from "../recipes/RecipeSourcesPanel";
import { RecipeTable } from "../recipes/RecipeTable";
import {
  RecipeTabs,
  type RecipesPageTab,
  isSourceTab,
  parseSourceTabValue,
} from "../recipes/RecipeTabs";
import { tryBuildCompleteImport } from "../recipes/recipe-import-draft";
import { useEnabledSources } from "../recipes/useEnabledSources";
import "./recipe-picker-dialog.scss";

/** Debounce for the search field — same value as `RecipesPage`'s. */
const SEARCH_DEBOUNCE_MS = 300;

/** Load state for the filtered catalog list, same discriminated-union shape as `RecipesPage`'s `RecipeListState`. */
type ListState =
  | { status: "loading" }
  | { status: "loaded"; recipes: RecipeSummaryView[] }
  | { status: "error" };

/**
 * The (day, meal) slot a `RecipePickerDialog` is adding a recipe to —
 * `date` is that day's `YYYY-MM-DD` (the specific date within the
 * displayed week, not just its weekday), needed by `POST /planning/items`
 * to resolve which week's `Planning` row to attach to.
 */
export interface PlanningSlot {
  date: string;
  weekDay: WeekDay;
  meal: Meal;
}

/**
 * Recipe-selection dialog opened from a planning grid cell's "+" button
 * (see `PlanningPage.tsx`'s `MealCell`) — the same catalog browsing
 * experience as `/recettes` (`RecipeTabs` + `RecipeTable`, reused as-is),
 * with three extra filters layered on top of the plain name search
 * (ingredients / regime / "convient à tout le foyer" toggle, all wired to
 * `GET /recipes`'s corresponding query params) since browsing here is
 * about finding something to cook, not just looking something up. Each
 * household-enabled source's own tab is included too: picking an
 * already-imported item behaves exactly like picking a regular recipe,
 * and picking one that isn't imported yet is what actually imports it —
 * nowhere else in the app does (see `handleSelectDraftItem`) — since a
 * source item only ever becomes a real, saved `Recipe` as a side effect of
 * someone adding it to their planning.
 *
 * Mounted only while open (see `PlanningPage`, same conditional-mount
 * convention as its own `CalendarPopover`) — every piece of local state
 * below resets for free the next time it's reopened, no manual reset
 * needed.
 *
 * Selecting a row doesn't navigate anywhere (unlike `RecipesPage`'s own
 * use of `RecipeTable`) — it switches this same dialog to a small
 * "how many portions?" confirmation step, then calls `POST
 * /planning/items` on submit. Picking a not-yet-imported source item is
 * handled differently still (`handleSelectDraftItem`): when the draft has
 * everything a real recipe needs, it's imported and added to this slot
 * transparently — no extra screen, same as picking anything else. Only
 * when something's actually missing (an ingredient the automatic matcher
 * couldn't resolve, say) does this navigate away entirely, to the review
 * screen (`/recettes/importer/...`), which has its own portions field
 * already.
 */
export function RecipePickerDialog({
  slot,
  onClose,
  onAdded,
}: {
  slot: PlanningSlot;
  onClose: () => void;
  onAdded: (item: PlanningItemView) => void;
}) {
  const { t } = useTranslation();
  const navigate = useNavigate();

  const [activeTab, setActiveTab] = useState<RecipesPageTab>("favoris");
  const activeSourceKey = parseSourceTabValue(activeTab);
  const enabledSources = useEnabledSources();
  const [search, setSearch] = useState("");
  const [debouncedSearch, setDebouncedSearch] = useState("");
  const [selectedIngredientIds, setSelectedIngredientIds] = useState<number[]>([]);
  const [selectedDietIds, setSelectedDietIds] = useState<number[]>([]);
  const [suitableForHousehold, setSuitableForHousehold] = useState(false);
  const [hasHousehold, setHasHousehold] = useState(false);
  const [isIngredientPickerOpen, setIsIngredientPickerOpen] = useState(false);

  const [ingredientsCatalog, setIngredientsCatalog] = useState<IngredientView[]>([]);
  const [dietsCatalog, setDietsCatalog] = useState<DietView[]>([]);
  const [listState, setListState] = useState<ListState>({ status: "loading" });
  // Set when picking an already-imported source item fails to resolve to a
  // real recipe (see `handleSelectImportedRecipe`) — a rare race (the
  // recipe was deleted between the browse fetch and the click), surfaced
  // the same way any other catalog load error is on this dialog.
  const [sourceSelectError, setSourceSelectError] = useState(false);
  // True while `handleSelectDraftItem` below is resolving a not-yet-
  // imported item's transparent-import attempt — replaces the source tab's
  // whole panel with a status message for that brief window (fetch the
  // draft, maybe import it, maybe add it to the slot) rather than leaving
  // the browse list clickable mid-flight.
  const [isAddingDraft, setIsAddingDraft] = useState(false);

  // The recipe picked in step 1 — `null` while still browsing, set once a
  // row is clicked to switch this dialog into its confirmation step.
  const [selectedRecipe, setSelectedRecipe] = useState<RecipeSummaryView | null>(null);
  const [portions, setPortions] = useState("1");
  const [isSubmitting, setIsSubmitting] = useState(false);
  const [submitError, setSubmitError] = useState<string | null>(null);

  useEffect(() => {
    const timeout = window.setTimeout(() => setDebouncedSearch(search), SEARCH_DEBOUNCE_MS);
    return () => window.clearTimeout(timeout);
  }, [search]);

  // Reference lists + "does the viewer have a household" — loaded once,
  // they don't change while the dialog is open.
  useEffect(() => {
    apiClient
      .getIngredients()
      .then(setIngredientsCatalog)
      .catch(() => setIngredientsCatalog([]));
    apiClient
      .getDiets()
      .then(setDietsCatalog)
      .catch(() => setDietsCatalog([]));
    apiClient
      .getCurrentHouse()
      .then((house) => setHasHousehold(house !== null))
      .catch(() => setHasHousehold(false));
  }, []);

  useEffect(() => {
    // A source's own tab doesn't query the recipe table at all — same
    // guard as `RecipesPage`'s own identical effect (the type-guard, not
    // just `activeSourceKey !== null`, is what narrows `activeTab` to
    // `RecipeTab` below).
    if (isSourceTab(activeTab)) return;
    let cancelled = false;
    setListState({ status: "loading" });

    apiClient
      .listRecipes(activeTab, {
        search: debouncedSearch.trim() || undefined,
        suitableForHousehold: suitableForHousehold || undefined,
        ingredientIds: selectedIngredientIds,
        dietIds: selectedDietIds,
      })
      .then((recipes) => {
        if (!cancelled) setListState({ status: "loaded", recipes });
      })
      .catch(() => {
        if (!cancelled) setListState({ status: "error" });
      });

    return () => {
      cancelled = true;
    };
  }, [activeTab, debouncedSearch, selectedIngredientIds, selectedDietIds, suitableForHousehold]);

  const selectedIngredients = ingredientsCatalog.filter((ingredient) =>
    selectedIngredientIds.includes(ingredient.id),
  );

  /** Picking an already-imported source item (one of the source tabs' `RecipeSourcesPanel`) — resolved to its full recipe, then treated exactly like picking that same recipe from one of the regular tabs, moving straight to the confirm-portions step below. */
  function handleSelectImportedRecipe(recipeId: number) {
    setSourceSelectError(false);
    apiClient
      .getRecipe(recipeId)
      .then((recipe) => {
        setSelectedRecipe(recipe);
        setPortions(String(recipe.portions));
      })
      .catch(() => setSourceSelectError(true));
  }

  /** Navigates away to the full review/creation screen, pre-filled from this exact item and carrying `slot` along so a successful import there adds straight to it — the fallback `handleSelectDraftItem` below takes whenever a transparent import isn't possible. */
  function goToReviewScreen(sourceKey: string, externalId: string) {
    navigate(
      `/recettes/importer/${sourceKey}/${encodeURIComponent(externalId)}` +
        `?planningDate=${slot.date}&planningWeekDay=${slot.weekDay}&planningMeal=${slot.meal}`,
    );
  }

  /**
   * Picking a not-yet-imported source item — the one action in the whole
   * app that actually imports one (see this component's own doc comment).
   * Fetches its full draft, and when {@link tryBuildCompleteImport} finds
   * nothing missing, imports it and adds it to `slot` transparently: no
   * extra screen, same end result as picking any other recipe. Anything
   * short of that — an unresolved ingredient, a network hiccup on any of
   * these three calls — falls back to the full review screen
   * (`goToReviewScreen`) instead, since only a person can supply what's
   * actually missing.
   */
  async function handleSelectDraftItem(item: BrowsableSourceItemView) {
    if (activeSourceKey === null) return;
    const sourceKey = activeSourceKey;
    setSourceSelectError(false);
    setIsAddingDraft(true);

    let payload: ReturnType<typeof tryBuildCompleteImport>;
    try {
      payload = tryBuildCompleteImport(
        await apiClient.previewSourceItem(sourceKey, item.externalId),
      );
    } catch {
      goToReviewScreen(sourceKey, item.externalId);
      return;
    }
    if (!payload) {
      setIsAddingDraft(false);
      goToReviewScreen(sourceKey, item.externalId);
      return;
    }

    let saved: RecipeView;
    try {
      saved = await apiClient.importSourceItem(sourceKey, item.externalId, payload);
    } catch {
      setIsAddingDraft(false);
      goToReviewScreen(sourceKey, item.externalId);
      return;
    }

    try {
      const planningItem = await apiClient.addPlanningItem({
        date: slot.date,
        weekDay: slot.weekDay,
        meal: slot.meal,
        recipeId: saved.id,
        portions: payload.portions,
      });
      onAdded(planningItem);
      onClose();
    } catch {
      // The recipe itself is already saved at this point — only adding it
      // to this slot failed. Land on its own page rather than retrying the
      // whole import through the review form (same fallback
      // `ImportRecipePage`'s own submit takes for the identical failure).
      navigate(`/recettes/${saved.id}`);
    }
  }

  async function handleConfirm() {
    if (!selectedRecipe) return;
    const parsedPortions = Number(portions);
    if (!Number.isInteger(parsedPortions) || parsedPortions < 1) return;

    setIsSubmitting(true);
    setSubmitError(null);
    try {
      const item = await apiClient.addPlanningItem({
        date: slot.date,
        weekDay: slot.weekDay,
        meal: slot.meal,
        recipeId: selectedRecipe.id,
        portions: parsedPortions,
      });
      onAdded(item);
      onClose();
    } catch (err) {
      const code = err instanceof ApiError ? err.code : ErrorCode.INTERNAL_ERROR;
      setSubmitError(errorMessageService.getLabel(code));
      setIsSubmitting(false);
    }
  }

  if (selectedRecipe) {
    return (
      <Dialog
        onClose={onClose}
        title={t("planning.picker.confirmTitle", { recipe: selectedRecipe.name })}
      >
        <div className="recipe-picker-confirm">
          <label htmlFor="planning-picker-portions">{t("planning.picker.portionsLabel")}</label>
          <input
            id="planning-picker-portions"
            type="number"
            min="1"
            step="1"
            value={portions}
            onChange={(e) => setPortions(e.target.value)}
          />
          {submitError && <p className="field-error">{submitError}</p>}
          <div className="recipe-picker-confirm__actions">
            <button type="button" onClick={() => setSelectedRecipe(null)} disabled={isSubmitting}>
              {t("planning.picker.backButton")}
            </button>
            <button
              type="button"
              className="recipe-picker-confirm__confirm"
              onClick={handleConfirm}
              disabled={isSubmitting}
            >
              {isSubmitting ? t("planning.picker.adding") : t("planning.picker.confirmButton")}
            </button>
          </div>
        </div>
      </Dialog>
    );
  }

  return (
    <Dialog onClose={onClose} title={t("planning.picker.title")} className="recipe-picker-dialog">
      {activeSourceKey === null && (
        <div className="recipe-picker__filters">
          <input
            type="search"
            className="recipe-picker__search"
            placeholder={t("planning.picker.searchPlaceholder")}
            value={search}
            onChange={(e) => setSearch(e.target.value)}
          />

          <div className="recipe-picker__ingredient-filter">
            <span className="recipe-picker__filter-label">
              {t("planning.picker.ingredientsFilterLabel")}
            </span>
            <div className="recipe-picker__chips">
              {selectedIngredients.map((ingredient) => (
                <span key={ingredient.id} className="filter-chip">
                  {t(`catalog.ingredients.${ingredient.key}`)}
                  <button
                    type="button"
                    onClick={() =>
                      setSelectedIngredientIds((ids) => ids.filter((id) => id !== ingredient.id))
                    }
                  >
                    ✕
                  </button>
                </span>
              ))}
              <button
                type="button"
                className="recipe-picker__toggle-ingredient-picker"
                onClick={() => setIsIngredientPickerOpen((open) => !open)}
                aria-expanded={isIngredientPickerOpen}
              >
                +{" "}
                {isIngredientPickerOpen
                  ? t("planning.picker.hideIngredientPicker")
                  : t("planning.picker.addIngredientFilter")}
              </button>
            </div>
            {isIngredientPickerOpen && (
              <IngredientPicker
                ingredients={ingredientsCatalog}
                excludeIds={selectedIngredientIds}
                onSelect={(ingredient) =>
                  setSelectedIngredientIds((ids) => [...ids, ingredient.id])
                }
              />
            )}
          </div>

          <DietTagSelect
            diets={dietsCatalog}
            value={selectedDietIds}
            onChange={setSelectedDietIds}
          />

          {hasHousehold && (
            <CheckboxOption checked={suitableForHousehold} onChange={setSuitableForHousehold}>
              {t("planning.picker.suitableForHouseholdLabel")}
            </CheckboxOption>
          )}
        </div>
      )}

      <RecipeTabs
        active={activeTab}
        onChange={setActiveTab}
        sources={enabledSources.status === "loaded" ? enabledSources.sources : []}
      />

      {activeSourceKey !== null ? (
        <>
          {sourceSelectError && (
            <p className="recipes-page__status recipes-page__status--error">
              {t("common.loadError")}
            </p>
          )}
          {isAddingDraft ? (
            <p className="recipes-page__status">{t("planning.picker.addingDraft")}</p>
          ) : (
            <RecipeSourcesPanel
              key={activeSourceKey}
              sourceKey={activeSourceKey}
              onSelectImportedRecipe={handleSelectImportedRecipe}
              onSelectDraftItem={handleSelectDraftItem}
            />
          )}
        </>
      ) : (
        <>
          {listState.status === "loading" && (
            <p className="recipes-page__status">{t("planning.picker.loading")}</p>
          )}
          {listState.status === "error" && (
            <p className="recipes-page__status recipes-page__status--error">
              {t("common.loadError")}
            </p>
          )}
          {listState.status === "loaded" && listState.recipes.length === 0 && (
            <p className="recipes-page__status">{t("planning.picker.empty")}</p>
          )}
          {listState.status === "loaded" && listState.recipes.length > 0 && (
            <RecipeTable
              recipes={listState.recipes}
              selectedId={null}
              onSelect={(id) => {
                const recipe = listState.recipes.find((r) => r.id === id) ?? null;
                setSelectedRecipe(recipe);
                // Pre-fill from the recipe's own written yield rather than
                // always starting at 1 — still freely editable below, this
                // is just a better starting point (see `Recipe.portions`).
                if (recipe) setPortions(String(recipe.portions));
              }}
            />
          )}
        </>
      )}
    </Dialog>
  );
}