import {
	useEffect,
	useRef,
} from '@wordpress/element'

import {
	useSelect,
} from '@wordpress/data'

import {
	useBlockEditContext,
	store as blockEditorStore,
	// @ts-expect-error
} from '@wordpress/block-editor'

import {
	debugLog,
	debugWarn,
	IS_DEV,
} from '@ska/utils'

import {
	useTailwindConfigVersion,
	applyTailwind,
} from '../../tailwind'

import {
	useBlocksPresets,
	getExpiredDynamicPresetsKey,
} from '../presets'

import {
	triggerCompiledEvent,
} from '../../plugins/options/plugin-icon'

import type {
	TailwindAttributes,
} from '../../types'

import type {
	tBlockAttributes,
} from '@ska/shared'

/** Store clientIds of blocks that are rendered in `core/post-template`. */
const PostTemplateBlocks = new Map<string, string>()

export const useIsPreviewMode = () => {

	const ctx = useBlockEditContext()

	if(Object(ctx).hasOwnProperty('isPreviewMode')) {
		debugWarn('`isPreviewMode` is public.') // API is public, code should be updated.
		return ctx.isPreviewMode
	}

	const symbols = Object.getOwnPropertySymbols(ctx)
	const isPreviewModeSymbol = symbols.find(s => s.toString().includes('isPreviewMode'))
	if(!isPreviewModeSymbol) {
		return false
	}

	return ctx[isPreviewModeSymbol]
}

export const useUpdateBlockInfo = (clientId: string, isInTemplate: boolean, className: string) => {

	useEffect(() => {
		/** Update classNames for use in clones. */
		if(isInTemplate && PostTemplateBlocks.get(clientId) !== className) {
			PostTemplateBlocks.set(clientId, className)
		}
	}, [isInTemplate, clientId, className])

	return null
}

export const useBlockInfo = (clientId: string, isSelectionEnabled: boolean) => {

	const {
		isInTemplate,
	} = useSelect(select => {

		const {
			getBlockParentsByBlockName,
		} = select(blockEditorStore)

		return {
			// In a template in query loop.
			isInTemplate: getBlockParentsByBlockName(clientId, 'core/post-template').length > 0,
		}
	}, [clientId])

	const className = PostTemplateBlocks.get(clientId)
	const isClone = !isInTemplate && className !== undefined // Is a copy in a query loop post template

	return {
		/** In a pattern preview, template preview or something like that. */
		isPreviewMode: useIsPreviewMode() || !isSelectionEnabled, // `useIsPreviewMode` sometimes lies, but `isSelectionEnabled` seems to be `false` when it does.
		/** In a (Query loop) Post template block? Only true for the "source" block and not for clones. */
		isInTemplate,
		/** A clone in a (Query loop) Post template block? */
		isClone,
		/** If it is a clone, then the source has these classes, and it should too. */
		sourceClassName: className,
	}
}

/**
 * Strip the `editor-preview` selector from block attributes - this selector is used to improve the
 * appearance of patterns when previewing them, but once the pattern is inserted it has no purpose.
 */
const withoutEditorPreviewSelector = (attributes: tBlockAttributes): tBlockAttributes => {

	// Kept in dev mode (when PHP `SKA_DEV` constant is defined) so that it's not lost when manually updating patterns.
	if(IS_DEV) {
		return attributes
	}

	if(!('skaBlocksSelectors' in attributes)) {
		return attributes
	}

	if(typeof attributes['skaBlocksSelectors'] !== 'object') {
		return attributes
	}

	if('editor-preview' in attributes['skaBlocksSelectors']) {

		const {
			'editor-preview': _,
			...restSelectors
		} = attributes['skaBlocksSelectors']

		return {
			...attributes,
			skaBlocksSelectors: {
				...restSelectors,
			},
		}
	}

	return attributes
}

/**
 * Recompile Tailwind CSS when applicable.
 */
export const useRecompile = (clientId: string, isCandidate: boolean, attributes: tBlockAttributes & TailwindAttributes, setAttributes: (attributes: tBlockAttributes) => void) => {

	const ver = useTailwindConfigVersion()
	const presets = useBlocksPresets(attributes, 'dynamic')
	const lastCompileKeyRef = useRef('')
	const compileFailedRef = useRef(false)

	useEffect(() => {

		/** Don't use recompile. */
		if(!isCandidate) {
			return
		}

		/** Compiler not ready yet. */
		if(ver < 0) {
			return
		}

		const {
			skaBlocks = {},
		} = attributes

		const {
			t = -1,
			p,
		} = skaBlocks

		const expiredVersionKey = t !== ver ? t.toString() : ''
		const expiredPresetsKey = getExpiredDynamicPresetsKey(p, presets)
		const compileKey = `${expiredVersionKey}${expiredPresetsKey}`

		/** Don't need to compile. */
		if(!compileKey) {

			// Since it's no longer need to compile, it's fine that the compile "failed"
			if(compileFailedRef.current) {
				compileFailedRef.current = false
			}

			return
		}

		/** Already compiled this state, but it didn't work or something undid it. */
		if(lastCompileKeyRef.current === compileKey) {

			// Warn when it happens more than once
			if(compileFailedRef.current) {
				debugWarn('Compile failed to persist', {clientId, compileKey, expiredVersionKey, expiredPresetsKey, attributes, presets, t, ver})
			}

			compileFailedRef.current = true
			return // Or potentially infinite loop
		}

		lastCompileKeyRef.current = compileKey
		debugLog('useRecompile compiling', clientId, compileKey, {expiredVersionKey, expiredPresetsKey, attributes, presets, t, ver})
		const nextAttributes = applyTailwind(withoutEditorPreviewSelector(attributes), presets)
		setAttributes(nextAttributes)
		triggerCompiledEvent()
	}, [isCandidate, ver, attributes, setAttributes, presets, clientId])

	return null
}