/// <reference path="../pb_data/types.d.ts" />
migrate(
  (app) => {
    // v4: ingredients become a many-to-many relation instead of the diet
    // select. Each ingredient carries its own icon (emoji) and diet class;
    // an item's veg/non-veg badge is derived from its ingredients. The menu
    // records are re-synced by scripts/update-menu.mjs.
    const ingredientsCollectionDef = () =>
      new Collection({
        name: 'ingredients',
        type: 'base',
        listRule: '',
        viewRule: '',
        createRule: null,
        updateRule: null,
        deleteRule: null,
        fields: [
          { name: 'uid', type: 'text', required: true },
          { name: 'name', type: 'text', required: true },
          { name: 'icon', type: 'text' },
          { name: 'diet_class', type: 'select', maxSelect: 1, values: ['veg', 'nonveg'], required: true },
          { name: 'sort', type: 'number' },
        ],
        indexes: ['CREATE UNIQUE INDEX idx_ingredients_uid ON ingredients (uid)'],
      })

    // app.save() returns nil (falsy) on success, so don't test its return
    // value — resolve the saved collection by name instead. The lookup-first
    // pattern keeps the migration idempotent if a previous run created the
    // collection before failing.
    let ingredientsCollection
    try {
      ingredientsCollection = app.findCollectionByNameOrId('ingredients')
    } catch (e) {
      app.save(ingredientsCollectionDef())
      ingredientsCollection = app.findCollectionByNameOrId('ingredients')
    }

    try {
      const oldCollection = app.findCollectionByNameOrId('menu_items')
      app.delete(oldCollection)
    } catch (e) {
      // collection may not exist on a fresh database — nothing to migrate
    }

    const menuItems = new Collection({
      name: 'menu_items',
      type: 'base',
      listRule: '',
      viewRule: '',
      createRule: null,
      updateRule: null,
      deleteRule: null,
      fields: [
        { name: 'uid', type: 'text', required: true },
        { name: 'category', type: 'text', required: true },
        { name: 'name', type: 'text', required: true },
        { name: 'variant', type: 'text' },
        { name: 'description', type: 'text' },
        { name: 'price', type: 'number', required: true },
        { name: 'ingredients', type: 'relation', collectionId: ingredientsCollection.id, cascadeDelete: false, maxSelect: 99 },
        { name: 'pairing', type: 'text' },
        { name: 'tag', type: 'text' },
        { name: 'image', type: 'text' },
        { name: 'sku', type: 'text' },
        { name: 'available', type: 'bool' },
        { name: 'tax_category', type: 'text' },
        { name: 'sort', type: 'number' },
      ],
      indexes: [
        'CREATE UNIQUE INDEX idx_menu_items_uid ON menu_items (uid)',
        'CREATE UNIQUE INDEX idx_menu_items_sku ON menu_items (sku) WHERE sku != \'\'',
      ],
    })
    return app.save(menuItems)
  },
  (app) => {
    // Revert to the v3 menu_items (diet select) and drop ingredients.
    try {
      const newCollection = app.findCollectionByNameOrId('menu_items')
      app.delete(newCollection)
    } catch (e) {
      // nothing to revert
    }

    const menuItems = new Collection({
      name: 'menu_items',
      type: 'base',
      listRule: '',
      viewRule: '',
      createRule: null,
      updateRule: null,
      deleteRule: null,
      fields: [
        { name: 'uid', type: 'text', required: true },
        { name: 'category', type: 'text', required: true },
        { name: 'name', type: 'text', required: true },
        { name: 'variant', type: 'text' },
        { name: 'description', type: 'text' },
        { name: 'price', type: 'number', required: true },
        { name: 'diet', type: 'select', maxSelect: 1, values: ['veg', 'nonveg', 'mixed'] },
        { name: 'pairing', type: 'text' },
        { name: 'tag', type: 'text' },
        { name: 'image', type: 'text' },
        { name: 'sku', type: 'text' },
        { name: 'available', type: 'bool' },
        { name: 'tax_category', type: 'text' },
        { name: 'sort', type: 'number' },
      ],
      indexes: [
        'CREATE UNIQUE INDEX idx_menu_items_uid ON menu_items (uid)',
        'CREATE UNIQUE INDEX idx_menu_items_sku ON menu_items (sku) WHERE sku != \'\'',
      ],
    })
    app.save(menuItems)

    try {
      const ingredients = app.findCollectionByNameOrId('ingredients')
      app.delete(ingredients)
    } catch (e) {
      // nothing to revert
    }
    return true
  }
)