import {
  applyItemUpsert,
  previewItemUpsert,
  searchItemDefinitions,
} from '../../api/stock.js';
import { fetchLocations } from '../../api/locations.js';
import { previewLabel } from '../../api/labels.js';
import { STORAGE_KEYS } from '../../app/config.js';
import { debounce, normalizeValidationError } from '../shared/form-utils.js';
import { loadStoredValue, saveStoredValue } from '../shared/storage.js';
import { createAsyncState, runAsyncState } from '../shared/ui-state.js';

const STOCK_TYPE_OPTIONS = [
  { value: 'measured', label: 'Measured' },
  { value: 'descriptive', label: 'Descriptive' },
  { value: 'binary', label: 'Binary' },
];

const STOCK_LEVEL_OPTIONS = [
  { value: 'plenty', label: 'Plenty (> 75%)' },
  { value: 'good', label: 'Good (> 50%)' },
  { value: 'some', label: 'Some (> 25%)' },
  { value: 'low', label: 'Low (> 10%)' },
  { value: 'trace', label: 'Trace (<= 10%)' },
  { value: 'gone', label: 'Gone (~= 0%)' },
];

const QUANTITY_UNIT_OPTIONS = ['g', 'ml', 'pc'];
const EXPIRATION_DAY_OPTIONS = ['3', '5', '8', '10', '15', '20', '25', '30', '45', '60', '90', '120', '150', '180'];

export function renderLabelCreatePage() {
  return `
    <section class="container-xxl py-4 py-lg-5" x-data="labelCreatePage()" x-init="init()">
      <div class="d-flex flex-column flex-lg-row justify-content-between gap-3 align-items-lg-end mb-4">
        <div>
          <p class="eyebrow mb-2">Label Creation</p>
          <h1 class="h3 mb-1">Create a stock label and entry</h1>
          <p class="text-body-secondary mb-0">
            Active kitchen:
            <span class="fw-semibold text-body" x-text="$store.app.activeKitchen?.name"></span>
          </p>
        </div>
        <div class="small text-body-secondary">
          Drafts are stored locally so small navigation changes do not wipe form input.
        </div>
      </div>

      <div class="row g-4">
        <div class="col-12 col-xl-7">
            <div class="card border-0 shadow-sm">
            <div class="card-body p-4">
              <form class="vstack gap-3" @submit.prevent="create()" autocomplete="off" x-ref="labelForm">
                <div class="position-relative search-field-with-clear">
                  <label class="form-label">Search item definitions</label>
                  <input class="form-control pe-5" type="text" x-model="form.search" @input="onSearchInput()" placeholder="Search by item name" autocomplete="off" />
                  <button
                    type="button"
                    class="btn btn-sm btn-link text-body-secondary clear-field-button search-clear-button"
                    x-show="form.search || form.itemId"
                    @click="clearItemSearch()"
                    aria-label="Clear item search"
                  >
                    &times;
                  </button>
                  <template x-if="suggestions.length">
                    <div class="list-group shadow-sm position-absolute start-0 end-0 z-3 mt-1 search-suggestions-picker">
                      <template x-for="item in suggestions" :key="item.id">
                        <button class="list-group-item list-group-item-action" type="button" @click="pickSuggestion(item)">
                          <div class="fw-semibold" x-text="item.name"></div>
                          <div class="small text-body-secondary" x-text="item.description || 'Existing item definition'"></div>
                        </button>
                      </template>
                    </div>
                  </template>
                </div>

                <div class="row g-3">
                  <div class="col-12 col-md-8 position-relative text-field-with-clear">
                    <label class="form-label">Title / name <span class="text-danger">*</span></label>
                    <input class="form-control pe-5" type="text" x-model="form.name" required />
                    <button
                      type="button"
                      class="btn btn-sm btn-link text-body-secondary clear-field-button inline-clear-button"
                      x-show="form.name"
                      @click="form.name = ''"
                      aria-label="Clear title"
                    >
                      &times;
                    </button>
                  </div>
                  <div class="col-12 position-relative text-field-with-clear">
                    <label class="form-label">Description</label>
                    <textarea class="form-control pe-5" rows="2" x-model="form.description"></textarea>
                    <button
                      type="button"
                      class="btn btn-sm btn-link text-body-secondary clear-field-button textarea-clear-button"
                      x-show="form.description"
                      @click="form.description = ''"
                      aria-label="Clear description"
                    >
                      &times;
                    </button>
                  </div>
                  <div class="col-12 col-md-4">
                    <label class="form-label">Stock type <span class="text-danger">*</span></label>
                    <select class="form-select" x-model="form.stockType" x-ref="stockTypeSelect" autocomplete="off" required>
                      <template x-for="option in stockTypeOptions" :key="option.value">
                        <option :value="option.value" x-text="option.label"></option>
                      </template>
                    </select>
                  </div>
                  <div class="col-12 col-md-6 grouped-field-with-clear">
                    <div class="grouped-field-footer mb-1">
                      <label class="form-label mb-0">
                        Quantity
                        <span class="text-danger" x-show="form.stockType === 'measured'">*</span>
                      </label>
                      <button
                        type="button"
                        class="btn btn-sm btn-link text-body-secondary p-0"
                        x-show="form.quantity || form.uom"
                        @click="clearQuantityFields()"
                      >
                        Clear quantity
                      </button>
                    </div>
                    <div class="row g-2">
                      <div class="col-7">
                        <input
                          class="form-control"
                          type="number"
                          step="0.01"
                          min="0"
                          x-model="form.quantity"
                          :required="form.stockType === 'measured'"
                        />
                      </div>
                      <div class="col-5">
                        <div
                          class="position-relative"
                          x-ref="quantityUnitPicker"
                          @focusin="quantityUnitPickerOpen = true"
                          @focusout="handleQuantityUnitFocusOut($event)"
                        >
                          <input
                            class="form-control"
                            type="text"
                            x-model="form.uom"
                            @input="onQuantityUnitInput()"
                            @click="openQuantityUnitPicker()"
                            @keydown.escape="quantityUnitPickerOpen = false"
                            placeholder="g"
                            autocomplete="off"
                          />
                          <template x-if="quantityUnitPickerOpen">
                            <div class="list-group shadow-sm position-absolute start-0 end-0 z-3 mt-1 quantity-unit-picker">
                              <template x-if="filteredQuantityUnits.length">
                                <div>
                                  <template x-for="unit in filteredQuantityUnits" :key="unit">
                                    <button
                                      class="list-group-item list-group-item-action"
                                      type="button"
                                      @click="pickQuantityUnit(unit)"
                                    >
                                      <span class="fw-semibold" x-text="unit"></span>
                                    </button>
                                  </template>
                                </div>
                              </template>
                              <template x-if="!filteredQuantityUnits.length">
                                <div class="list-group-item text-body-secondary">
                                  No matching units found.
                                </div>
                              </template>
                            </div>
                          </template>
                        </div>
                      </div>
                    </div>
                    <div class="row g-2 mt-1">
                      <div class="col-7">
                        <div class="small text-body-secondary">Amount</div>
                      </div>
                      <div class="col-5">
                        <div class="small text-body-secondary">Unit</div>
                      </div>
                    </div>
                  </div>
                  <div class="col-12 col-md-6" x-show="form.stockType === 'descriptive'">
                      <label class="form-label">Stock level</label>
                      <select class="form-select" x-model="form.level" x-ref="stockLevelSelect">
                        <option value="">Select level</option>
                        <template x-for="option in stockLevelOptions" :key="option.value">
                          <option :value="option.value" x-text="option.label"></option>
                        </template>
                      </select>
                  </div>
                  <div class="col-12 col-md-6 grouped-field-with-clear">
                    <div class="grouped-field-footer mb-1">
                      <label class="form-label mb-0">Energy</label>
                      <button
                        type="button"
                        class="btn btn-sm btn-link text-body-secondary p-0"
                        x-show="form.energy !== '' || form.energyUnit"
                        @click="clearEnergyFields()"
                      >
                        Clear energy
                      </button>
                    </div>
                    <div class="row g-2">
                      <div class="col-5">
                        <input class="form-control" type="number" step="0.01" min="0" x-model="form.energy" />
                      </div>
                      <div class="col-7">
                        <input class="form-control" type="text" x-model="form.energyUnit" placeholder="kcal (100g/ml)" />
                      </div>
                    </div>
                    <div class="row g-2 mt-1">
                      <div class="col-5">
                        <div class="small text-body-secondary">Value</div>
                      </div>
                      <div class="col-7">
                        <div class="small text-body-secondary">Unit</div>
                      </div>
                    </div>
                  </div>
                  <div class="col-12 col-md-6">
                    <label class="form-label">Storage location <span class="text-danger">*</span></label>
                    <div
                      class="position-relative location-field-with-clear"
                      x-ref="locationPicker"
                      @focusin="locationPickerOpen = true"
                      @focusout="handleLocationFocusOut($event)"
                    >
                      <input
                        class="form-control pe-5"
                        type="text"
                        x-model="locationSearch"
                        x-ref="locationInput"
                        @input="onLocationInput()"
                        @keydown.escape="locationPickerOpen = false"
                        @click="openLocationPicker()"
                        placeholder="Search location"
                        autocomplete="off"
                        required
                      />
                      <button
                        type="button"
                        class="btn btn-sm btn-link text-body-secondary clear-field-button location-clear-button"
                        x-show="locationSearch || form.locationId"
                        @click="clearLocation()"
                        aria-label="Clear selected location"
                      >
                        &times;
                      </button>
                      <input type="hidden" x-model="form.locationId" />
                      <template x-if="locationPickerOpen">
                        <div class="list-group shadow-sm position-absolute start-0 end-0 z-3 mt-1 location-picker">
                          <template x-if="filteredLocations.length">
                            <div>
                              <template x-for="location in filteredLocations" :key="location.id">
                                <button
                                  class="list-group-item list-group-item-action"
                                  type="button"
                                  @mousedown.prevent
                                  @touchstart.prevent="pickLocation(location)"
                                  @click="pickLocation(location)"
                                  :style="locationItemStyle(location)"
                                >
                                  <div class="d-flex align-items-center gap-2">
                                    <span
                                      class="location-level-badge"
                                      x-show="location.depth"
                                      x-text="locationLevelLabel(location)"
                                    ></span>
                                    <div class="fw-semibold" x-text="location.name"></div>
                                  </div>
                                  <div class="small text-body-secondary" x-text="locationPathHint(location)"></div>
                                </button>
                              </template>
                            </div>
                          </template>
                          <template x-if="!filteredLocations.length">
                            <div class="list-group-item text-body-secondary">
                              No matching locations found.
                            </div>
                          </template>
                        </div>
                      </template>
                    </div>
                    <div class="form-text" x-show="selectedLocationPath" x-text="selectedLocationPath"></div>
                  </div>
                  <div class="col-12 col-md-6">
                    <label class="form-label">Production date <span class="text-danger">*</span></label>
                    <input class="form-control" type="date" x-model="form.productionDate" required />
                  </div>
                  <div class="col-12 col-md-6 grouped-field-with-clear">
                    <div class="grouped-field-footer mb-1">
                      <label class="form-label mb-0">Expiration</label>
                      <button
                        type="button"
                        class="btn btn-sm btn-link text-body-secondary p-0"
                        x-show="form.expirationDate || form.expireDays"
                        @click="clearExpirationDate()"
                      >
                        Clear expiration date
                      </button>
                    </div>
                    <div class="row g-2">
                      <div class="col-5">
                        <div
                          class="position-relative"
                          x-ref="expireDaysPicker"
                          @focusin="expireDaysPickerOpen = true"
                          @focusout="handleExpireDaysFocusOut($event)"
                        >
                          <input
                            class="form-control"
                            type="text"
                            inputmode="numeric"
                            x-model="form.expireDays"
                            @focus="expireDaysFieldFocused = true"
                            @blur="expireDaysFieldFocused = false"
                            @input="onExpireDaysInput()"
                            @click="openExpireDaysPicker()"
                            @keydown.escape="expireDaysPickerOpen = false"
                            placeholder="30"
                            autocomplete="off"
                          />
                          <template x-if="expireDaysPickerOpen && !isCompactExpireDaysLayout()">
                            <div class="shadow-sm position-absolute start-0 end-0 z-3 mt-1 quantity-unit-picker expiration-days-picker">
                              <template x-if="filteredExpireDayOptions.length">
                                <div class="expiration-days-grid">
                                  <template x-for="days in filteredExpireDayOptions" :key="days">
                                    <button
                                      class="btn btn-outline-secondary btn-sm expiration-days-option"
                                      type="button"
                                      @mousedown.prevent
                                      @touchstart.prevent="pickExpireDays(days)"
                                      @click="pickExpireDays(days)"
                                      :class="{ 'active': form.expireDays === days }"
                                    >
                                      <span class="fw-semibold" x-text="days"></span>
                                    </button>
                                  </template>
                                </div>
                              </template>
                              <template x-if="!filteredExpireDayOptions.length">
                                <div class="text-body-secondary small p-3">
                                  No matching day values found.
                                </div>
                              </template>
                            </div>
                          </template>
                        </div>
                      </div>
                      <div class="col-7">
                        <input
                          class="form-control"
                          type="date"
                          x-model="form.expirationDate"
                          @input="syncExpireDaysFromDate()"
                        />
                      </div>
                    </div>
                    <template x-if="isCompactExpireDaysLayout() && expireDaysFieldFocused">
                      <div class="expiration-days-inline mt-2">
                        <div class="small text-body-secondary mb-2">Quick picks</div>
                        <div class="expiration-days-grid expiration-days-grid-inline">
                          <template x-for="days in filteredExpireDayOptions" :key="days">
                            <button
                              class="btn btn-outline-secondary btn-sm expiration-days-option"
                              type="button"
                              @touchstart.prevent="pickExpireDays(days)"
                              @click="pickExpireDays(days)"
                              :class="{ 'active': form.expireDays === days }"
                            >
                              <span class="fw-semibold" x-text="days"></span>
                            </button>
                          </template>
                        </div>
                      </div>
                    </template>
                    <div class="row g-2 mt-1">
                      <div class="col-5">
                        <div class="small text-body-secondary">Days</div>
                      </div>
                      <div class="col-7">
                        <div class="small text-body-secondary">Date</div>
                      </div>
                    </div>
                    <div class="form-text">Enter either days or a date. The other field updates automatically.</div>
                  </div>
                </div>

                <template x-if="submitError">
                  <div class="alert alert-danger mb-0">
                    <div class="fw-semibold mb-1">Could not save this stock entry.</div>
                    <div x-text="submitError"></div>
                  </div>
                </template>

                <template x-if="successMessage">
                  <div class="alert alert-success mb-0" x-text="successMessage"></div>
                </template>

                <template x-if="upsertPreview && !upsertPreview.error">
                  <div class="alert alert-info mb-0 py-2" x-text="upsertPreviewSummary()"></div>
                </template>

                <template x-if="upsertPreview?.error">
                  <div class="alert alert-warning mb-0 py-2" x-text="upsertPreview.error"></div>
                </template>

                <div class="d-flex flex-wrap justify-content-between align-items-center gap-2">
                  <div class="d-flex flex-wrap gap-2">
                    <button class="btn btn-outline-primary" type="button" @click="preview()" :disabled="previewState.isLoading">
                      <span x-show="!previewState.isLoading">Preview label</span>
                      <span x-show="previewState.isLoading">Rendering preview...</span>
                    </button>
                    <button class="btn btn-primary" type="submit" :disabled="createState.isLoading">
                      <span x-show="!createState.isLoading">Save stock entry</span>
                      <span x-show="createState.isLoading">Saving...</span>
                    </button>
                  </div>
                  <button class="btn btn-outline-secondary" type="button" @click="reset()">Clear form</button>
                </div>
                <div class="small text-body-secondary">
                  <span class="text-danger">*</span> Required field
                </div>
              </form>
            </div>
          </div>
        </div>

        <div class="col-12 col-xl-5" x-show="previewUrl">
          <div class="card border-0 shadow-sm h-100">
            <div class="card-body p-4">
              <div class="d-flex justify-content-between align-items-center mb-3">
                <div>
                  <h2 class="h5 mb-1">Label preview</h2>
                  <p class="text-body-secondary small mb-0">PNG and SVG responses are both supported.</p>
                </div>
              </div>

              <template x-if="previewState.error">
                <div class="alert alert-warning" x-text="previewState.error"></div>
              </template>

              <template x-if="previewUrl">
                <div class="preview-frame">
                  <img class="img-fluid rounded-3 border" :src="previewUrl" alt="Generated label preview" />
                </div>
              </template>
            </div>
          </div>
        </div>
      </div>
    </section>
  `;
}

function todayIsoDate() {
  const now = new Date();
  const year = now.getFullYear();
  const month = String(now.getMonth() + 1).padStart(2, '0');
  const day = String(now.getDate()).padStart(2, '0');
  return `${year}-${month}-${day}`;
}

function addDaysToIsoDate(isoDate, days) {
  const [year, month, day] = isoDate.split('-').map(Number);
  const date = new Date(year, month - 1, day);
  date.setDate(date.getDate() + days);
  const nextYear = date.getFullYear();
  const nextMonth = String(date.getMonth() + 1).padStart(2, '0');
  const nextDay = String(date.getDate()).padStart(2, '0');
  return `${nextYear}-${nextMonth}-${nextDay}`;
}

function diffDays(fromIsoDate, toIsoDate) {
  const [fromYear, fromMonth, fromDay] = fromIsoDate.split('-').map(Number);
  const [toYear, toMonth, toDay] = toIsoDate.split('-').map(Number);
  const fromDate = new Date(fromYear, fromMonth - 1, fromDay);
  const toDate = new Date(toYear, toMonth - 1, toDay);
  const millisecondsPerDay = 24 * 60 * 60 * 1000;
  return Math.round((toDate - fromDate) / millisecondsPerDay);
}

function createDefaultForm() {
  return {
    itemId: '',
    itemUuidB64: '',
    identifierCode: '',
    externalSource: '',
    externalId: '',
    search: '',
    name: '',
    description: '',
    quantity: '',
    uom: 'g',
    stockType: 'binary',
    level: 'plenty',
    energy: '',
    energyUnit: 'kcal (100g/ml)',
    productionDate: todayIsoDate(),
    expireDays: '',
    expirationDate: '',
    locationId: '',
  };
}

function loadLabelDraft() {
  const draft = loadStoredValue(STORAGE_KEYS.labelDraft, createDefaultForm());

  return {
    ...createDefaultForm(),
    ...draft,
    quantity:
      draft.quantity === 0 || draft.quantity === '0' || draft.quantity == null
        ? ''
        : draft.quantity,
    itemId: '',
    itemUuidB64: '',
    identifierCode: '',
    externalSource: '',
    externalId: '',
    search: '',
  };
}

function buildDraftPayload(form) {
  return {
    ...form,
    itemId: '',
    itemUuidB64: '',
    identifierCode: '',
    externalSource: '',
    externalId: '',
    search: '',
  };
}

export function labelCreatePageData(store) {
  return {
    previewState: createAsyncState(),
    createState: createAsyncState(),
    stockTypeOptions: STOCK_TYPE_OPTIONS,
    stockLevelOptions: STOCK_LEVEL_OPTIONS,
    quantityUnitOptions: QUANTITY_UNIT_OPTIONS,
    expirationDayOptions: EXPIRATION_DAY_OPTIONS,
    suggestions: [],
    locations: [],
    locationSearch: '',
    locationPickerOpen: false,
    quantityUnitPickerOpen: false,
    expireDaysPickerOpen: false,
    expireDaysFieldFocused: false,
    previewUrl: '',
    successMessage: '',
    submitError: '',
    fieldErrors: {},
    upsertPreview: null,
    form: {
      ...loadLabelDraft(),
    },
    async init() {
      if (!store.isConnected) {
        return;
      }
      await this.loadLocations();
      this.$watch('form', () => this.persistDraft(), { deep: true });
      this.$watch('form.stockType', (value) => {
        this.syncStockTypeState(value);
        this.syncStockTypeSelect();
        this.syncStockLevelSelect();
      });
      this.$watch('form.level', () => this.syncStockLevelSelect());
      this.$watch('form.productionDate', () => {
        if (this.form.expireDays !== '') {
          this.syncExpireDateFromDays();
          return;
        }

        if (this.form.expirationDate) {
          this.syncExpireDaysFromDate();
        }
      });
      this.syncStockTypeState(this.form.stockType);
      this.syncStockTypeSelect();
      this.syncStockLevelSelect();
      this.searchDebounced = debounce(async () => {
        if (this.form.search.trim().length <= 2) {
          this.suggestions = [];
          return;
        }

        this.suggestions = await searchItemDefinitions(store, this.form.search.trim());
      }, 250);
    },
    async loadLocations() {
      if (!store.isConnected) {
        return;
      }

      try {
        const { flat } = await fetchLocations(store);
        this.locations = flat;
        this.syncLocationSelection();
      } catch (error) {
        store.addAlert({
          type: 'warning',
          message: `Locations could not be loaded: ${error.message}`,
        });
      }
    },
    onSearchInput() {
      this.upsertPreview = null;
      if (this.form.itemUuidB64 || this.form.itemId) {
        this.form.itemId = '';
        this.form.itemUuidB64 = '';
        this.form.identifierCode = '';
        this.form.externalSource = '';
        this.form.externalId = '';
      }
      this.persistDraft();
      this.searchDebounced();
    },
    pickSuggestion(item) {
      const baseProductionDate = this.form.productionDate || todayIsoDate();
      const expirationDays =
        typeof item.expiration_days === 'number'
          ? item.expiration_days
          : item.date && item.expire_date
            ? diffDays(item.date, item.expire_date)
            : null;

      this.form.itemId = item.id;
      this.form.itemUuidB64 = item.uuid_b64 || '';
      this.form.identifierCode = item.identifier_code || '';
      this.form.externalSource = item.external_source || '';
      this.form.externalId = item.external_id || '';
      this.form.search = item.name;
      this.form.name = item.name;
      this.form.description = item.description || this.form.description;
      this.form.uom = item.uom_symbol || this.form.uom;
      this.form.quantity =
        item.quantity_initial
          ? String(item.quantity_initial)
          : this.form.quantity;
      this.form.stockType = item.stock_type || this.form.stockType;
      this.form.level = item.level || this.form.level;
      if (expirationDays !== null && expirationDays >= 0) {
        this.form.expireDays = String(expirationDays);
        this.form.expirationDate = addDaysToIsoDate(baseProductionDate, expirationDays);
      }
      this.applyItemLocation(item.location_initial_uuid_b64);
      this.suggestions = [];
      this.persistDraft();
    },
    clearItemSearch() {
      this.form.itemId = '';
      this.form.itemUuidB64 = '';
      this.form.identifierCode = '';
      this.form.externalSource = '';
      this.form.externalId = '';
      this.form.search = '';
      this.upsertPreview = null;
      this.suggestions = [];
      this.persistDraft();
    },
    persistDraft() {
      saveStoredValue(STORAGE_KEYS.labelDraft, buildDraftPayload(this.form));
    },
    get filteredLocations() {
      const query = this.locationSearch.trim().toLowerCase();
      const selectedLabel = this.selectedLocation
        ? this.selectedLocation.name.toLowerCase()
        : '';

      if (selectedLabel && query === selectedLabel) {
        return this.locations;
      }

      if (!query) {
        return this.locations;
      }

      return this.locations.filter((location) =>
        `${location.name} ${location.pathLabel}`.toLowerCase().includes(query),
      );
    },
    get filteredQuantityUnits() {
      const query = this.form.uom.trim().toLowerCase();
      if (!query) {
        return this.quantityUnitOptions;
      }

      if (this.quantityUnitOptions.some((unit) => unit.toLowerCase() === query)) {
        return this.quantityUnitOptions;
      }

      const matches = this.quantityUnitOptions.filter((unit) =>
        unit.toLowerCase().includes(query),
      );

      if (matches.length) {
        return matches;
      }

      return this.quantityUnitOptions;
    },
    get filteredExpireDayOptions() {
      const query = this.form.expireDays.trim();
      if (!query) {
        return this.expirationDayOptions;
      }

      if (this.expirationDayOptions.includes(query)) {
        return this.expirationDayOptions;
      }

      const matches = this.expirationDayOptions.filter((days) =>
        days.includes(query),
      );

      if (matches.length) {
        return matches;
      }

      return this.expirationDayOptions;
    },
    get selectedLocation() {
      return this.locations.find(
        (location) => String(location.id) === String(this.form.locationId),
      ) || null;
    },
    get selectedLocationPath() {
      return this.selectedLocation?.pathLabel || '';
    },
    pickLocation(location) {
      this.form.locationId = String(location.id);
      this.locationSearch = location.name;
      this.locationPickerOpen = false;
      this.syncLocationValidity();
      this.persistDraft();
    },
    clearLocation() {
      this.form.locationId = '';
      this.locationSearch = '';
      this.locationPickerOpen = true;
      this.syncLocationValidity();
      this.persistDraft();
    },
    openLocationPicker() {
      this.locationPickerOpen = true;
    },
    openQuantityUnitPicker() {
      this.quantityUnitPickerOpen = true;
    },
    openExpireDaysPicker() {
      if (this.isCompactExpireDaysLayout()) {
        this.expireDaysPickerOpen = false;
        return;
      }

      this.expireDaysPickerOpen = true;
    },
    onLocationInput() {
      this.locationPickerOpen = true;
      if (this.selectedLocation && this.locationSearch !== this.selectedLocation.name) {
        this.form.locationId = '';
      }
      this.syncLocationValidity();
    },
    handleLocationFocusOut(event) {
      const nextTarget = event.relatedTarget;
      if (nextTarget && this.$refs.locationPicker?.contains(nextTarget)) {
        return;
      }

      this.locationPickerOpen = false;
    },
    onQuantityUnitInput() {
      this.quantityUnitPickerOpen = true;
    },
    handleQuantityUnitFocusOut(event) {
      const nextTarget = event.relatedTarget;
      if (nextTarget && this.$refs.quantityUnitPicker?.contains(nextTarget)) {
        return;
      }

      this.quantityUnitPickerOpen = false;
    },
    onExpireDaysInput() {
      if (!this.isCompactExpireDaysLayout()) {
        this.expireDaysPickerOpen = true;
      }
      this.syncExpireDateFromDays();
    },
    handleExpireDaysFocusOut(event) {
      if (this.isCompactExpireDaysLayout()) {
        return;
      }

      const nextTarget = event.relatedTarget;
      if (nextTarget && this.$refs.expireDaysPicker?.contains(nextTarget)) {
        return;
      }

      this.expireDaysPickerOpen = false;
    },
    isCompactExpireDaysLayout() {
      return window.matchMedia('(max-width: 575.98px)').matches;
    },
    pickQuantityUnit(unit) {
      this.form.uom = unit;
      this.quantityUnitPickerOpen = false;
    },
    pickExpireDays(days) {
      this.form.expireDays = days;
      this.expireDaysPickerOpen = false;
      this.syncExpireDateFromDays();
    },
    syncLocationSelection() {
      if (!this.form.locationId) {
        this.locationSearch = '';
        return;
      }

      const selected = this.locations.find(
        (location) => String(location.id) === String(this.form.locationId),
      );

      this.locationSearch = selected ? selected.name : '';
      this.syncLocationValidity();
    },
    applyItemLocation(locationUuidB64) {
      if (!locationUuidB64) {
        return;
      }

      const location = this.locations.find(
        (entry) => entry.uuid_b64 === locationUuidB64,
      );

      if (!location) {
        return;
      }

      this.form.locationId = String(location.id);
      this.locationSearch = location.name;
      this.syncLocationValidity();
    },
    syncLocationValidity() {
      const input = this.$refs.locationInput;
      if (!input) {
        return;
      }

      if (!this.locationSearch.trim()) {
        input.setCustomValidity('Please select a storage location.');
        return;
      }

      if (!this.form.locationId) {
        input.setCustomValidity('Please choose a location from the list.');
        return;
      }

      input.setCustomValidity('');
    },
    validateBeforeSubmit() {
      this.syncLocationValidity();
      const form = this.$refs.labelForm;
      if (!form) {
        return true;
      }

      return form.reportValidity();
    },
    syncExpireDateFromDays() {
      if (this.form.expireDays === '') {
        return;
      }

      const days = Number(this.form.expireDays);
      if (Number.isNaN(days) || days < 0) {
        return;
      }

      const baseDate = this.form.productionDate || todayIsoDate();
      this.form.expirationDate = addDaysToIsoDate(baseDate, days);
    },
    syncExpireDaysFromDate() {
      if (!this.form.expirationDate) {
        this.form.expireDays = '';
        return;
      }

      const baseDate = this.form.productionDate || todayIsoDate();
      const days = diffDays(baseDate, this.form.expirationDate);
      this.form.expireDays = days >= 0 ? String(days) : '';
    },
    clearExpirationDate() {
      this.form.expirationDate = '';
      this.form.expireDays = '';
    },
    clearEnergyFields() {
      this.form.energy = '';
      this.form.energyUnit = 'kcal (100g/ml)';
    },
    clearQuantityFields() {
      this.form.quantity = '';
      this.form.uom = 'g';
    },
    syncStockTypeState(stockType) {
      if (stockType === 'measured') {
        this.form.level = '';
        if (this.form.uom === '') {
          this.form.uom = 'g';
        }
        return;
      }

      if (stockType === 'binary' && this.form.level !== 'plenty') {
        this.form.level = 'plenty';
        return;
      }

      if (stockType === 'descriptive' && (!this.form.level || this.form.level === '')) {
        this.form.level = 'plenty';
      }
    },
    syncStockTypeSelect() {
      if (this.$refs.stockTypeSelect) {
        this.$refs.stockTypeSelect.value = this.form.stockType;
      }
    },
    syncStockLevelSelect() {
      if (this.$refs.stockLevelSelect) {
        this.$refs.stockLevelSelect.value = this.form.level || 'plenty';
      }
    },
    buildPayload() {
      const quantity =
        this.form.quantity === ''
          ? this.form.stockType === 'binary'
            ? 1
            : null
          : Number(this.form.quantity);

      const selectedLocationUuidB64 = this.selectedLocation?.uuid_b64 || null;

      return {
        item_id: this.form.itemId || null,
        name: this.form.name.trim(),
        description: this.form.description.trim(),
        quantity_initial: quantity,
        uom_symbol: this.form.uom.trim() || null,
        calories: this.form.energy === '' ? null : Number(this.form.energy),
        calories_unit: this.form.energyUnit.trim() || null,
        stock_type: this.form.stockType,
        level: this.form.stockType === 'measured' ? null : this.form.level || null,
        date: this.form.productionDate || null,
        expire_date: this.form.expirationDate || null,
        location_initial: selectedLocationUuidB64,
        kitchen_id: store.activeKitchen?.id || null,
      };
    },
    buildUpsertPayload() {
      const basePayload = this.buildPayload();
      const itemPayload = {
        name: basePayload.name,
        description: basePayload.description,
        quantity_initial: basePayload.quantity_initial,
        uom_symbol: basePayload.uom_symbol,
        calories: basePayload.calories,
        calories_unit: basePayload.calories_unit,
        stock_type: basePayload.stock_type,
        level: basePayload.level,
        date: basePayload.date,
        expire_date: basePayload.expire_date,
        location_initial: basePayload.location_initial,
      };

      return {
        uuid_b64: this.form.itemUuidB64 || null,
        identifier_code: this.form.identifierCode || null,
        external_source: this.form.externalSource || null,
        external_id: this.form.externalId || null,
        item: itemPayload,
      };
    },
    upsertPreviewSummary() {
      if (!this.upsertPreview || this.upsertPreview.error) {
        return '';
      }

      if (this.upsertPreview.operation === 'update') {
        const name = this.upsertPreview.matchedItem?.name || this.form.name;
        const matchType = this.upsertPreview.matchType ? ` (matched by ${this.upsertPreview.matchType})` : '';
        return `Submit will update: ${name}${matchType}.`;
      }

      return 'Submit will create a new stock item.';
    },
    async preview() {
      this.submitError = '';
      this.fieldErrors = {};
      this.upsertPreview = null;

      if (!this.validateBeforeSubmit()) {
        this.previewState.error = 'Please fill out the required fields before previewing the label.';
        return;
      }

      await runAsyncState(this.previewState, async () => {
        this.successMessage = '';
        const result = await previewLabel(store, this.buildPayload());
        if (this.previewUrl && this.previewUrl.startsWith('blob:')) {
          URL.revokeObjectURL(this.previewUrl);
        }
        this.previewUrl = result.objectUrl;
        try {
          this.upsertPreview = await previewItemUpsert(store, this.buildUpsertPayload());
        } catch (error) {
          this.upsertPreview = {
            error: error.message || 'Upsert preview failed.',
          };
        }
        this.persistDraft();
      });
    },
    async create() {
      this.submitError = '';
      this.fieldErrors = {};

      if (!this.validateBeforeSubmit()) {
        this.submitError = 'Please fill out the required fields before saving the stock entry.';
        return;
      }

      await runAsyncState(this.createState, async () => {
        try {
          const entry = await applyItemUpsert(store, this.buildUpsertPayload());
          if (this.previewUrl && this.previewUrl.startsWith('blob:')) {
            URL.revokeObjectURL(this.previewUrl);
          }
          this.previewUrl = '';
          const entryName = entry.item?.name || this.form.name;
          const operationVerb = entry.operation === 'update' ? 'updated' : 'created';
          this.successMessage = `${entryName} was ${operationVerb} successfully.`;
          store.addAlert({
            type: 'success',
            message: `${entryName} was ${operationVerb} successfully.`,
          });
          this.upsertPreview = entry;
          saveStoredValue(STORAGE_KEYS.labelDraft, buildDraftPayload(this.form));
        } catch (error) {
          this.fieldErrors = normalizeValidationError(error);
          this.submitError = error.message;
          throw error;
        }
      }).catch(() => {});
    },
    reset(revokePreview = true) {
      this.form = createDefaultForm();
      this.syncStockTypeState(this.form.stockType);
      this.suggestions = [];
      this.locationSearch = '';
      this.locationPickerOpen = false;
      this.successMessage = '';
      this.submitError = '';
      this.fieldErrors = {};
      this.upsertPreview = null;
      saveStoredValue(STORAGE_KEYS.labelDraft, this.form);
      if (revokePreview && this.previewUrl.startsWith('blob:')) {
        URL.revokeObjectURL(this.previewUrl);
      }
      this.previewUrl = '';
    },
    locationItemStyle(location) {
      const depth = location.depth || 0;
      return `padding-left: calc(1rem + ${depth} * 1rem);`;
    },
    locationLevelLabel(location) {
      return `L${(location.depth || 0) + 1}`;
    },
    locationPathHint(location) {
      if (!location.depth) {
        return location.type || 'Top-level location';
      }

      const segments = location.pathLabel.split(' / ');
      return `Inside ${segments.slice(0, -1).join(' / ')}`;
    },
  };
}