import { autoResize } from "./autoResize.js"
import type { NotionDataSource } from "./bridge/dataSources/dataSource.js"
import type {
	CustomBlockHostState,
	InitializedHostState,
} from "./bridge/hostState.js"
import type { NotionBlockId } from "./bridge/ids.js"
import type { CustomBlockManifest } from "./bridge/manifest.js"
import type { CustomBlockPage } from "./bridge/pages/page.js"
import type { NotionParent } from "./bridge/parent.js"
import { customBlockHost } from "./bridge/sandboxClient.js"
import type { NotionTheme } from "./bridge/theme.js"
import type { NotionUser } from "./bridge/users/user.js"

export type CustomBlockState =
	| { status: "uninitialized"; theme: NotionTheme }
	| {
			status: "initialized"
			theme: NotionTheme
			blockId: NotionBlockId
			parent: NotionParent
			page: CustomBlockPage
			currentUser: NotionUser
			dataSources: NotionDataSource[]
	  }

/**
 * Framework-neutral runtime state APIs for a custom block. Call `initCustomBlock`
 * before reading initialized values, and use `subscribe` to react to host pushes.
 */
export const customBlock = {
	subscribe(listener: () => void): () => void {
		return customBlockHost.subscribe(listener)
	},

	getState(): CustomBlockState {
		return toPublicState(customBlockHost.getState())
	},

	getCurrentUser(): NotionUser {
		return getInitializedHostState("getCurrentUser").currentUser
	},

	getTheme(): NotionTheme {
		return getInitializedHostState("getTheme").theme
	},

	getBlockId(): NotionBlockId {
		return getInitializedHostState("getBlockId").blockId
	},

	getParent(): NotionParent {
		return getInitializedHostState("getParent").parent
	},

	getPage(): CustomBlockPage {
		return getInitializedHostState("getPage").page
	},

	getManifest(): CustomBlockManifest | null {
		return customBlockHost.getManifest()
	},

	autoResize,
}

let lastHostState: CustomBlockHostState | undefined
let lastPublicState: CustomBlockState | undefined

function toPublicState(hostState: CustomBlockHostState): CustomBlockState {
	if (hostState === lastHostState && lastPublicState !== undefined) {
		return lastPublicState
	}
	lastHostState = hostState
	if (hostState.status === "uninitialized") {
		lastPublicState = {
			status: "uninitialized",
			theme: hostState.theme,
		}
		return lastPublicState
	}
	lastPublicState = {
		status: "initialized",
		theme: hostState.theme,
		blockId: hostState.blockId,
		parent: hostState.parent,
		page: hostState.page,
		currentUser: hostState.currentUser,
		dataSources: hostState.dataSources,
	}
	return lastPublicState
}

function getInitializedHostState(methodName: string): InitializedHostState {
	const hostState = customBlockHost.getState()
	if (hostState.status !== "initialized") {
		throw new Error(
			`customBlock.${methodName} called before \`initCustomBlock\` resolved. Await it before reading runtime state.`,
		)
	}
	return hostState
}