@prismicio/types-internal/src/content/Document.ts

Prismic types for Custom Types and Prismic Data

import { either } from "fp-ts"
import { isLeft, isRight } from "fp-ts/lib/Either"
import { pipe } from "fp-ts/lib/function"
import * as t from "io-ts"

import {
	ContentPath,
	TraverseSliceContentFn,
	TraverseWidgetContentFn,
} from "../_internal/utils"
import { WidgetKey } from "../common"
import { UUID } from "../common/UUID"
import {
	type StaticWidget,
	collectSharedSlices,
	flattenSections,
	NestableWidget,
	StaticCustomType,
} from "../customtypes"
import {
	groupContentWithDefaultValues,
	isGroupContent,
	isSlicesContent,
	migrateSliceItem,
	NestableContentDefaultValue,
	slicesContentWithDefaultValues,
	traverseGroupContent,
	traverseRepeatableContent,
	traverseSlices,
	traverseTableContent,
	WidgetContent,
	WidgetLegacy,
} from "./fields"
import {
	defaultCtx,
	FieldOrSliceType,
	LegacyContentCtx,
	WithTypes,
} from "./LegacyContentCtx"

export const Document = t.record(WidgetKey, WidgetContent)
export type Document = t.TypeOf<typeof Document>

const legacyDocReader = t.record(WidgetKey, t.unknown)
type DocumentLegacy = t.TypeOf<typeof legacyDocReader>

/**
 * `DocumentLegacyCodec` handles decoding and encoding documents to the legacy
 * format used by Prismic DB, therefore, this function itself is not "legacy".
 */
const DocumentLegacyCodec = (
	allTypes?: LegacyContentCtx["allTypes"],
	allKeys?: LegacyContentCtx["allKeys"],
) => {
	return new t.Type<Document, WithTypes<DocumentLegacy>, unknown>(
		"Document",
		(u): u is Document => !!u && typeof u === "object",
		(doc) => {
			return pipe(
				legacyDocReader.decode(doc),
				either.map((parsedDoc) => {
					return Object.entries(parsedDoc).reduce(
						(acc, [widgetKey, widgetValue]) => {
							const widgetCtx = defaultCtx(widgetKey, allTypes, allKeys)
							const parsedW = WidgetLegacy(widgetCtx).decode(widgetValue)
							if (!parsedW || isLeft(parsedW)) return acc

							return { ...acc, [widgetKey]: parsedW.right }
						},
						{},
					)
				}),
			)
		},
		(g: Document) => {
			return Object.entries(g).reduce(
				(acc, [key, value]) => {
					const widgetCtx = defaultCtx(key, allTypes)
					const result = WidgetLegacy(widgetCtx).encode(value)
					if (!result) return acc

					return {
						content: { ...acc.content, [key]: result.content },
						types: { ...acc.types, ...result.types },
						keys: { ...acc.keys, ...result.keys },
					}
				},
				{ content: {}, types: {}, keys: {} },
			)
		},
	)
}

function extractMetadata(data: { [p: string]: unknown }): {
	types: Map<string, FieldOrSliceType>
	widgets: Partial<Record<WidgetKey, unknown>>
	keys: Map<string, string>
	slugs: ReadonlyArray<string>
	uid: string | undefined
} {
	const fields: [string, unknown][] = Object.entries(data)

	const { types, widgets, keys } = fields.reduce(
		(acc, [k, v]) => {
			if (k.endsWith("_TYPE")) {
				const decodedValue = FieldOrSliceType.decode(v)
				if (isRight(decodedValue)) {
					return {
						...acc,
						types: acc.types.set(
							k.substring(0, k.length - 5),
							decodedValue.right,
						),
					}
				}
			}
			if (k.endsWith("_KEY")) {
				const decodedValue = UUID.decode(v)
				if (isRight(decodedValue)) {
					return {
						...acc,
						keys: acc.keys.set(
							k.substring(0, k.length - 4),
							decodedValue.right,
						),
					}
				}
			}
			if (
				!k.endsWith("_POSITION") &&
				!k.endsWith("_TYPE") &&
				!k.endsWith("_KEY")
			) {
				return {
					...acc,
					widgets: {
						...acc.widgets,
						[k]: v,
					},
				}
			}
			return acc
		},
		{
			types: new Map<string, FieldOrSliceType>(),
			widgets: {},
			keys: new Map<string, string>(),
		},
	)

	const slugs = (data["slugs_INTERNAL"] as string[]) || []
	const uid = data["uid"] as string | undefined

	return {
		widgets,
		types,
		keys,
		uid,
		slugs,
	}
}

function parseLegacyDocument(
	legacyDoc: unknown,
	customType:
		| StaticCustomType
		| {
				customTypeId: string
				fields: Record<string, StaticWidget>
		  },
): Document | undefined {
	const result = pipe(
		// ensure it's the right document format first
		t.record(WidgetKey, t.unknown).decode(legacyDoc),
		either.chain((doc) => {
			// extract all metadata, meaning all _TYPES keys from legacy format + the widgets as unknown
			const { types, widgets, keys } = extractMetadata(doc)
			// parse the actual widgets
			return DocumentLegacyCodec(types, keys).decode(widgets)
		}),
	)

	return isLeft(result) ? undefined : migrateDocument(result.right, customType)
}

function encodeToLegacyDocument(document: Document): DocumentLegacy {
	const encoded = DocumentLegacyCodec().encode(document)
	return { ...encoded.content, ...encoded.types, ...encoded.keys }
}

export const DocumentLegacy = {
	_codec: DocumentLegacyCodec,
	extractMetadata,
	parse: parseLegacyDocument,
	encode: encodeToLegacyDocument,
}

function simplifyCustomType(customType: StaticCustomType): {
	customTypeId: string
	fields: Record<string, StaticWidget>
} {
	return {
		customTypeId: customType?.id,
		fields: Object.fromEntries(flattenSections(customType)),
	}
}

export function fillDocumentWithDefaultValues(
	customType:
		| StaticCustomType
		| {
				customTypeId: string
				fields: Record<string, StaticWidget>
		  },
	document: Document,
): Document {
	const { fields } =
		customType && StaticCustomType.is(customType)
			? simplifyCustomType(customType)
			: customType

	return Object.entries(fields).reduce<Document>(
		(updatedDocument, [fieldKey, fieldDef]) => {
			const fieldContent = document[fieldKey]

			const updatedField = (() => {
				switch (fieldDef.type) {
					case "Group":
						return isGroupContent(fieldContent)
							? groupContentWithDefaultValues(fieldDef, fieldContent)
							: fieldContent
					case "Choice":
					case "Slices":
						return isSlicesContent(fieldContent)
							? slicesContentWithDefaultValues(fieldDef, fieldContent)
							: fieldContent
					default:
						return fieldContent === undefined && NestableWidget.is(fieldDef)
							? NestableContentDefaultValue(fieldDef)
							: fieldContent
				}
			})()

			return updatedField
				? {
						...updatedDocument,
						[fieldKey]: updatedField,
				  }
				: updatedDocument
		},
		document,
	)
}
/**
 * @param model: Can be optional if we simply want to loop through the content
 *   without any consideration for the attached model
 * @param document: The content we actually want to iterate on in an immutable fashion
 * @param transform: A user function that provides a way to transform any kind
 *   of content wherever it is in a structured Prismic object content.
 * @returns A transformed document with the user's transformation applied with
 *   the transform function
 */
export function traverseDocument({
	document,
	customType,
}: {
	document: Document
	customType?:
		| StaticCustomType
		| {
				customTypeId: string
				fields: Record<string, StaticWidget>
		  }
		| undefined
}) {
	const model =
		customType && StaticCustomType.is(customType)
			? simplifyCustomType(customType)
			: customType
	return ({
		transformWidget = ({ content }) => content,
		transformSlice = ({ content }) => content,
	}: {
		transformWidget?: TraverseWidgetContentFn
		transformSlice?: TraverseSliceContentFn
	}): Document => {
		const fieldModels =
			model &&
			Object.entries(model.fields).reduce<Record<string, StaticWidget>>(
				(acc, [key, def]) => ({ ...acc, [key]: def }),
				{},
			)

		return Object.entries(document).reduce((acc, [key, content]) => {
			const fieldModel = fieldModels && fieldModels[key]

			const path = ContentPath.make([
				{ key: model?.customTypeId, type: "CustomType" },
				{ key, type: "Widget" },
			])

			const transformedWidget = (() => {
				switch (content.__TYPE__) {
					case "SliceContentType":
						return traverseSlices({
							path,
							key,
							model:
								fieldModel?.type === "Slices" || fieldModel?.type === "Choice"
									? fieldModel
									: undefined,
							content,
						})({ transformWidget, transformSlice })
					case "GroupContentType":
						return traverseGroupContent({
							path,
							key,
							apiId: key,
							model: fieldModel?.type === "Group" ? fieldModel : undefined,
							content,
						})(transformWidget)
					case "RepeatableContent":
						return traverseRepeatableContent({
							path,
							key,
							apiId: key,
							model: fieldModel?.type === "Link" ? fieldModel : undefined,
							content,
						})(transformWidget)
					case "TableContent":
						return traverseTableContent({
							path,
							key,
							apiId: key,
							model: fieldModel?.type === "Table" ? fieldModel : undefined,
							content,
						})(transformWidget)
					default:
						return transformWidget({
							path,
							key,
							apiId: key,
							model:
								fieldModel?.type !== "Group" &&
								fieldModel?.type !== "Slices" &&
								fieldModel?.type !== "Choice"
									? fieldModel
									: undefined,
							content,
						})
				}
			})()

			return {
				...acc,
				...(transformedWidget ? { [key]: transformedWidget } : {}),
			}
		}, {})
	}
}

// /**
//  * The goal is to be able to collect all widgets or slices of a given type at any level of nesting inside a prismic content
//  *
//  * @param document parsed prismic content
//  * @param is typeguard to match specifically the type of widget we want to collect
//  * @returns a record containing the path of the widget as key and the typed collected content as value
//  */
export function collectWidgets<W extends WidgetContent>(
	document: Document,
	is: (content: WidgetContent, path: ContentPath) => content is W,
): Record<string, W> {
	const collected: Record<string, W> = {}

	traverseDocument({ document })({
		transformWidget: ({ content, path }) => {
			const key = ContentPath.serialize(path)
			if (is(content, path)) collected[key] = content
			return content
		},
	})
	return collected
}

export function migrateDocument(
	document: Document,
	customType:
		| StaticCustomType
		| {
				customTypeId: string
				fields: Record<string, StaticWidget>
		  },
) {
	const model = StaticCustomType.is(customType)
		? simplifyCustomType(customType)
		: customType
	const needsMigration = Object.values(collectSharedSlices(model)).some(
		(slice) => Boolean(slice.legacyPaths),
	)

	if (!needsMigration) return document

	return traverseDocument({
		document,
		customType,
	})({
		transformSlice: migrateSliceItem,
	})
}