import type { ApplogValue } from '../../applog/datom-types.ts'
import type { ISchemaAdapter, VMAttributeDef } from '../types.ts'
import type { ZodObject, ZodType, ZodTypeAny } from 'zod'

/**
 * Create a schema adapter from a Zod object schema.
 *
 * Usage:
 * ```ts
 * import { z } from 'zod'
 * import { createZodAdapter } from '@wovin/core/viewmodel/adapters/zod'
 *
 * const MySchema = z.object({
 *   name: z.string(),
 *   age: z.number().optional(),
 * })
 *
 * const adapter = createZodAdapter(MySchema, 'myEntity')
 * ```
 *
 * The type parameter `T` is the inferred type of the schema.
 */
export function createZodAdapter<T extends Record<string, ApplogValue> = Record<string, ApplogValue>>(
	zodSchema: ZodObject<Record<string, ZodTypeAny>>,
	entityPrefix: string,
	options?: {
		/** Override at-paths for specific attributes */
		atOverrides?: Record<string, string>
		/** Default values */
		defaults?: Partial<T>
		/** Property name to at-path mapping function */
		toAtPath?: (entityPrefix: string, attrName: string) => string
	},
): ISchemaAdapter<T> {
	const shape = zodSchema.shape as Record<string, ZodTypeAny>
	const toAtPath = options?.toAtPath ?? ((prefix, name) => `${prefix}/${name}`)

	const attributeDefs: VMAttributeDef[] = Object.entries(shape).map(([name, fieldSchema]: [string, ZodTypeAny]) => {
		const isOptional = fieldSchema.isOptional() || fieldSchema.isNullable()
		const atPath = options?.atOverrides?.[name] ?? toAtPath(entityPrefix, name)

		return {
			name,
			atPath,
			optional: isOptional,
		}
	})

	return {
		getAttributeDefs: () => attributeDefs,
		getDefaults: () => (options?.defaults ?? {}) as Partial<T>,
		getEntityPrefix: () => entityPrefix,
		createValidator: () => (value: unknown): value is T => zodSchema.safeParse(value).success,
	}
}