import type { StandardSchemaV1 } from "@standard-schema/spec";

// --- Env definition types ---

/** A binding definition — either a Standard Schema validator or a binding type checker */
export type BindingDef = StandardSchemaV1 | BindingTypeCheck;

/** Binding type check for CF-specific bindings (KV, D1, R2, etc.) */
export interface BindingTypeCheck {
	readonly __bindingType: string;
	readonly validate: (value: unknown) => boolean;
}

/** An env schema — mapping of binding names to their definitions */
export type EnvSchema = Record<string, BindingDef>;

/** Infer the parsed env type from a schema definition */
export type InferEnv<S extends EnvSchema> = {
	[K in keyof S]: S[K] extends StandardSchemaV1<any, infer O>
		? O
		: S[K] extends BindingTypeCheck
			? InferBindingType<S[K]>
			: unknown;
};

/** Map binding type check to its runtime type */
export type InferBindingType<B extends BindingTypeCheck> = B["__bindingType"] extends "KVNamespace"
	? KVNamespace
	: B["__bindingType"] extends "D1Database"
		? D1Database
		: B["__bindingType"] extends "R2Bucket"
			? R2Bucket
			: B["__bindingType"] extends "DurableObjectNamespace"
				? DurableObjectNamespace
				: B["__bindingType"] extends "Queue"
					? Queue
					: B["__bindingType"] extends "Fetcher"
						? Fetcher
						: B["__bindingType"] extends "AnalyticsEngineDataset"
							? AnalyticsEngineDataset
							: unknown;

// --- Env parse result ---

export interface EnvParseSuccess<T> {
	readonly success: true;
	readonly env: T;
}

export interface EnvParseFailure {
	readonly success: false;
	readonly errors: EnvValidationError[];
}

export interface EnvValidationError {
	readonly binding: string;
	readonly message: string;
	readonly expected: string;
	readonly received: string;
}

export type EnvParseResult<T> = EnvParseSuccess<T> | EnvParseFailure;