import { writable, derived } from "svelte/store"
import manifest from "@budibase/standard-components/manifest.json"

const dispatchEvent = (type, data) => {
  window.dispatchEvent(
    new CustomEvent("bb-event", {
      detail: { type, data },
    })
  )
}

const findComponentById = (component, componentId) => {
  if (!component || !componentId) {
    return null
  }
  if (component._id === componentId) {
    return component
  }
  if (!component._children?.length) {
    return null
  }
  for (let child of component._children) {
    const result = findComponentById(child, componentId)
    if (result) {
      return result
    }
  }
  return null
}

const createBuilderStore = () => {
  const initialState = {
    inBuilder: false,
    appId: null,
    layout: null,
    screen: null,
    selectedComponentId: null,
    previewId: null,
    previewType: null,
  }
  const writableStore = writable(initialState)
  const derivedStore = derived(writableStore, $state => {
    // Derive the selected component instance and definition
    const { layout, screen, previewType, selectedComponentId } = $state
    const asset = previewType === "layout" ? layout : screen
    const component = findComponentById(asset?.props, selectedComponentId)
    const prefix = "@budibase/standard-components/"
    const type = component?._component?.replace(prefix, "")
    const definition = type ? manifest[type] : null
    return {
      ...$state,
      selectedComponent: component,
      selectedComponentDefinition: definition,
    }
  })

  const actions = {
    selectComponent: id => {
      if (id) {
        dispatchEvent("select-component", { id })
      }
    },
    updateProp: (prop, value) => {
      dispatchEvent("update-prop", { prop, value })
    },
  }
  return {
    ...writableStore,
    subscribe: derivedStore.subscribe,
    actions,
  }
}

export const builderStore = createBuilderStore()