import * as Effect from "effect/Effect";
import * as Schema from "effect/Schema";
import * as SchemaIssue from "effect/SchemaIssue";
import { RpcClientError } from "effect/unstable/rpc";

import * as AcpSchema from "../_generated/schema.gen.ts";
import * as AcpError from "../errors.ts";

const formatSchemaIssue = SchemaIssue.makeFormatterDefault();

export const callRpc = <A>(
  effect: Effect.Effect<A, RpcClientError.RpcClientError | AcpSchema.Error>,
): Effect.Effect<A, AcpError.AcpError> =>
  effect.pipe(
    Effect.catchTag("RpcClientError", (error) =>
      Effect.fail(
        new AcpError.AcpTransportError({
          detail: error.message,
          cause: error,
        }),
      ),
    ),
    Effect.catchIf(Schema.is(AcpSchema.Error), (error) =>
      Effect.fail(AcpError.AcpRequestError.fromProtocolError(error)),
    ),
  );

export const runHandler = Effect.fnUntraced(function* <A, B>(
  handler: ((payload: A) => Effect.Effect<B, AcpError.AcpError>) | undefined,
  payload: A,
  method: string,
) {
  if (!handler) {
    return yield* Effect.fail(AcpError.AcpRequestError.methodNotFound(method).toProtocolError());
  }
  return yield* handler(payload).pipe(
    Effect.mapError((error) =>
      Schema.is(AcpError.AcpRequestError)(error)
        ? error.toProtocolError()
        : AcpError.AcpRequestError.internalError(error.message).toProtocolError(),
    ),
  );
});

export function decodeExtRequestRegistration<A, I>(
  method: string,
  payload: Schema.Codec<A, I>,
  handler: (payload: A) => Effect.Effect<unknown, AcpError.AcpError>,
) {
  return (params: unknown): Effect.Effect<unknown, AcpError.AcpError> =>
    Schema.decodeUnknownEffect(payload)(params).pipe(
      Effect.mapError((error) =>
        AcpError.AcpRequestError.invalidParams(
          `Invalid ${method} payload: ${formatSchemaIssue(error.issue)}`,
          { issue: error.issue },
        ),
      ),
      Effect.flatMap((decoded) => handler(decoded)),
    );
}

export function decodeExtNotificationRegistration<A, I>(
  method: string,
  payload: Schema.Codec<A, I>,
  handler: (payload: A) => Effect.Effect<void, AcpError.AcpError>,
) {
  return (params: unknown): Effect.Effect<void, AcpError.AcpError> =>
    Schema.decodeUnknownEffect(payload)(params).pipe(
      Effect.mapError(
        (error) =>
          new AcpError.AcpProtocolParseError({
            detail: `Invalid ${method} notification payload: ${formatSchemaIssue(error.issue)}`,
            cause: error,
          }),
      ),
      Effect.flatMap((decoded) => handler(decoded)),
    );
}

const encoder = new TextEncoder();

const JsonRpcId = Schema.Union([Schema.Number, Schema.String]);
const JsonRpcHeaders = Schema.Array(Schema.Unknown);

export const jsonRpcRequest = <A, I>(method: string, params: Schema.Codec<A, I>) =>
  Schema.Struct({
    jsonrpc: Schema.Literal("2.0"),
    id: JsonRpcId,
    method: Schema.Literal(method),
    params,
    headers: JsonRpcHeaders,
  });

export const jsonRpcNotification = <A, I>(method: string, params: Schema.Codec<A, I>) =>
  Schema.Struct({
    jsonrpc: Schema.Literal("2.0"),
    method: Schema.Literal(method),
    params,
  });

export const jsonRpcResponse = <A, I>(result: Schema.Codec<A, I>) =>
  Schema.Struct({
    jsonrpc: Schema.Literal("2.0"),
    id: JsonRpcId,
    result,
  });

export const encodeJsonl = <A, I>(schema: Schema.Codec<A, I>, value: A) =>
  Effect.map(Schema.encodeEffect(Schema.fromJsonString(schema))(value), (encoded) =>
    encoder.encode(`${encoded}\n`),
  );