import { Router, type Request, type Response } from 'express';
import type { AnyAPIExecuter, APINamespace } from './defs.js';
import type { RawArgType } from '@strpc/def';
import type { SafeParseReturnType, ZodType } from 'zod';
import { flatten } from 'lodash-es';

const PRINT_API_CALL = true;

// eslint-disable-next-line @typescript-eslint/no-explicit-any
async function parseParam<Q extends RawArgType>(req: Request, argValidator?: ZodType<Q>): Promise<SafeParseReturnType<Q, Q>> {
    if (!argValidator) {
        return {
            success: true,
            data: req.query as Q
        }
    }

    const query = req.query;
    return await argValidator.safeParseAsync(query);
}

// eslint-disable-next-line @typescript-eslint/no-explicit-any
async function parseBody<Q extends RawArgType>(req: Request, argValidator?: ZodType<Q>): Promise<SafeParseReturnType<Q, Q>> {
    if (!argValidator) {
        return {
            success: true,
            data: req.body as Q
        }
    }

    const query = req.body;
    return await argValidator.safeParseAsync(query);
}

async function apiRun<Q extends RawArgType>(query: Q, req: Request, res: Response, api: AnyAPIExecuter): Promise<void> {
    const [preResult, ctx] = await api.preDecorator({}, req, res);
    if (!preResult.every((v) => v.result)) {
        const lastErr = preResult.pop() as typeof preResult[0];

        const [postResult,] = await api.postDecorator(ctx, preResult, req, res, false);
        const postErrors = postResult.filter((obj) => !obj.result);
        if (postErrors.length) {
            //회수조차 불가능?
            if (PRINT_API_CALL) {
                console.log(JSON.stringify([(new Date).toISOString(), req.ip, req.path, false, 'preDecorator', lastErr.type, lastErr.info]));
            }
            res.json({
                result: false,
                path: req.path,
                reason: lastErr.info,
                recovery: lastErr.recovery,
                detail: {
                    type: 'decorator',
                    preDecorator: [lastErr.type, lastErr.info],
                    postDecorator: flatten(postErrors.map((obj) => [obj.type, obj.info])),
                },
            });
            return;
        }

        if (PRINT_API_CALL) {
            console.log(JSON.stringify([(new Date).toISOString(), req.ip, req.path, false, 'preDecorator', lastErr.type, lastErr.info]));
        }
        res.json({
            result: false,
            path: req.path,
            reason: lastErr.info,
            recovery: lastErr.recovery,
            detail: {
                type: 'decorator',
                preDecorator: [lastErr.type, lastErr.info],
            },
        })
        return;
    }
    const result = await api(query, ctx, req, res);
    const [postResult,] = await api.postDecorator(ctx, preResult, req, res, true);
    const postErrors = postResult.filter((obj) => !obj.result);
    if (postErrors.length) {
        const lastErr = postErrors.pop() as typeof postErrors[0];
        if (PRINT_API_CALL) {
            console.log(JSON.stringify([(new Date).toISOString(), req.ip, req.path, false, 'postDecorator', lastErr.type, lastErr.info]));
        }
        if (result === true) {
            //NOTE: 이미 api에서 response를 보낸 특이 케이스.
            return;
        }
        res.json({
            result: false,
            path: req.path,
            reason: lastErr?.info,
            recovery: lastErr?.recovery,
            detail: {
                type: 'decorator',
                preDecorator: flatten(postErrors.map((obj) => [obj.type, obj.info])),
            },
            originalResult: result,
        });
        return;
    }

    if (PRINT_API_CALL) {
        if(result === true){
            console.log(JSON.stringify([(new Date).toISOString(), req.ip, req.path, true, 'passThrough']));
        }
        else{
            let tmp_result = true;
            let tmp_reason = undefined;
            if('result' in result){
                tmp_result = result.result;
            }
            if('reason' in result){
                tmp_reason = result.reason;
            }
            console.log(JSON.stringify([(new Date).toISOString(), req.ip, req.path, tmp_result, tmp_reason]));
        }

    }

    if (result !== true) {
        res.json(result);
    }
}

export function buildAPISystem<N extends APINamespace, Q extends AnyAPIExecuter>(api: N | Q): Router {
    const router = Router();

    if (typeof api === 'function') {
        throw 'root api cannot be function';
    }

    for (const [key, value] of Object.entries(api)) {
        const rkey = `/${key}`;
        if (typeof value !== 'function') {
            router.use(rkey, buildAPISystem(value));

            continue;
        }
        const executer = value;

        if (!executer.httpMethod) {
            throw new Error('APIExecuter.reqType is not defined');
        }

        const parser = executer.httpMethod === 'get' ? parseParam : parseBody;
        router[executer.httpMethod](rkey, async (req, res) => {
            const queryResult = await parser(req, executer.argValidator);
            if (!queryResult.success) {
                res.json({
                    result: false,
                    reason: `invalid parameter: ${queryResult.error.message}`,
                    error: queryResult.error
                });
                return;
            }

            await apiRun(queryResult.data, req, res, executer);
        });
    }
    return router;
}