import {createLogger, debugType} from "@gongt/ts-stl-library/debug/create-logger";
import {LOG_LEVEL} from "@gongt/ts-stl-library/debug/levels";
import {ApiResponse, STATUS_CODE_BASE} from "@gongt/ts-stl-library/request/protocol";
import {ErrorResponse} from "@gongt/ts-stl-library/request/request-error";
import {hintErrorStack} from "@gongt/ts-stl-library/strings/hint-error-stack";
import {RequestContext} from "./base/context";
import {ExpressHandler} from "./base/handler";
import {AssignFunction, AssignObjectFunction, MultiValueResponseWrapper} from "./base/response-wrapper";

export class JsonApiHandler<ReqType, ResType> extends ExpressHandler<ReqType, ResType, JsonApiRequestContext<ReqType, ResType>> {
	protected instanceContext(req, res) {
		res.setHeader('Content-Type', 'application/json; charset=utf-8');
		return new JsonApiRequestContext<ReqType, ResType>(req, res);
	}
}

export class JsonApiRequestContext<ReqType, ResType> extends RequestContext<ReqType, ResType> {
	public assign: AssignFunction;
	public assignObject: AssignObjectFunction;
	
	public readonly response: JsonApiResponseWrapper<ResType>;
	
	protected createResponseWrapper(): JsonApiResponseWrapper<ResType> {
		const resp = new JsonApiResponseWrapper<ResType>(this.res);
		
		this.assign = resp.assign.bind(resp);
		this.assignObject = resp.assignObject.bind(resp);
		
		return resp;
	}
}

const debugSill = createLogger(LOG_LEVEL.SILLY, 'response');

export class JsonApiResponseWrapper<ResType> extends MultiValueResponseWrapper<ResType> {
	result: (ResType&ApiResponse)|ErrorResponse = {} as any;
	
	redirect(target: string, permanent: boolean = false) {
		throw new TypeError('do not allow json api redirect.');
	}
	
	protected asyncResolve(res: ResType): void {
		this.assignObject(res);
	}
	
	protected asyncReject(error: any): void {
		this.internalError(error);
	}
	
	protected _send() {
		// debugSill('???', this.result)
		if (this.result.status === STATUS_CODE_BASE.NO_RESPONSE) {
			debugSill('     added STATUS_CODE_BASE.SUCCESS as `status`');
			this.result.status = STATUS_CODE_BASE.SUCCESS;
		}
		if (debugSill.enabled) {
			debugSill('     with json: %j', debugType(this.result));
		}
		let data: string;
		try {
			data = JSON.stringify(this.result);
		} catch (e) {
			hintErrorStack(e.stack);
			console.error(this.result);
			throw e;
		}
		this.response.send(data);
	}
}