import {
	Editor,
	FileHelpers,
	TLImageExportOptions,
	TLShapeId,
	exhaustiveSwitchError,
} from '@tldraw/editor'
import {
	clipboardWrite,
	doesClipboardSupportType,
	getAdditionalClipboardWriteType,
} from '../clipboard'
import { exportToImagePromiseForClipboard } from './export'

/** @public */
export type TLCopyType = 'svg' | 'png' | 'json'

/** @public */
export interface CopyAsOptions extends Omit<TLImageExportOptions, 'format'> {
	/** The format to copy as. */
	format: TLCopyType
}

/**
 * Copy the given shapes to the clipboard.
 *
 * @param editor - The editor instance.
 * @param ids - The ids of the shapes to copy.
 * @param format - The format to copy as. Defaults to png.
 * @param opts - Options for the copy.
 *
 * @public
 */
export function copyAs(editor: Editor, ids: TLShapeId[], opts: CopyAsOptions): Promise<void> {
	// Note:  it's important that this function itself isn't async and doesn't really use promises -
	// we need to create the relevant `ClipboardItem`s and call navigator.clipboard.write
	// synchronously to make sure safari knows that the user _wants_ to copy See
	// https://bugs.webkit.org/show_bug.cgi?id=222262

	if (!navigator.clipboard) return Promise.reject(new Error('Copy not supported'))

	if (opts.format === 'json') {
		const content = editor.getContentFromCurrentPage(ids)
		const jsonStr = JSON.stringify(content, null, '\t')
		return navigator.clipboard.writeText(jsonStr)
	}

	const imageOpts: TLImageExportOptions = {
		...opts,
		format: opts.format as TLImageExportOptions['format'],
	}

	if (navigator.clipboard.write as any) {
		const { blobPromise, mimeType } = exportToImagePromiseForClipboard(editor, ids, imageOpts)

		const types: Record<string, Promise<Blob>> = { [mimeType]: blobPromise }
		const additionalMimeType = getAdditionalClipboardWriteType(opts.format)
		if (additionalMimeType && doesClipboardSupportType(additionalMimeType)) {
			types[additionalMimeType] = blobPromise.then((blob) =>
				FileHelpers.rewriteMimeType(blob, additionalMimeType)
			)
		}

		return clipboardWrite(types)
	}

	switch (opts.format) {
		case 'svg': {
			return fallbackWriteTextAsync(async () => {
				const result = await editor.getSvgString(ids, imageOpts)

				if (!result) throw new Error('Failed to copy')
				return result.svg
			})
		}

		case 'png':
			throw new Error('Copy not supported')
		default:
			exhaustiveSwitchError(opts.format)
	}
}

async function fallbackWriteTextAsync(getText: () => Promise<string>) {
	await navigator.clipboard?.writeText?.(await getText())
}