import { defineEventHandler } from 'h3'
import { config } from '~~/server/utils/config';
import { generate_challenge, kCTFChallengeConfig, Argon2ChallengeConfig, SHA256ChallengeConfig } from '@impost/lib/validator';
import { ChallengeStrategy, ChallengeAlgorithm } from '@impost/lib';
import { CHALLENGE_TIMEOUT_MS, outstandingChallenges } from '~~/server/utils/pow';

export default defineEventHandler(async () => {
    let challenge_config;
    switch (config.algorithm) {
        case ChallengeAlgorithm.SHA256:
            switch (config.strategy) {
                case ChallengeStrategy.LeadingZeroes:
                    challenge_config = {
                        algorithm: ChallengeAlgorithm.SHA256,
                        strategy: ChallengeStrategy.LeadingZeroes,
                        difficulty: config.leading_zeroes.difficulty,
                        parameters: { expires_at: Date.now() + CHALLENGE_TIMEOUT_MS },
                    } as SHA256ChallengeConfig;
                    break;
                case ChallengeStrategy.TargetNumber:
                    challenge_config = {
                        algorithm: ChallengeAlgorithm.SHA256,
                        strategy: ChallengeStrategy.TargetNumber,
                        difficulty: config.target_number.max_number,
                        parameters: { expires_at: Date.now() + CHALLENGE_TIMEOUT_MS },
                    } as SHA256ChallengeConfig;
                    break;
            }
            break;
        case ChallengeAlgorithm.Argon2id:
            switch (config.strategy) {
                case ChallengeStrategy.LeadingZeroes:
                    challenge_config = {
                        algorithm: ChallengeAlgorithm.Argon2id,
                        strategy: ChallengeStrategy.LeadingZeroes,
                        difficulty: config.leading_zeroes.difficulty,
                        parameters: { expires_at: Date.now() + CHALLENGE_TIMEOUT_MS },
                    } as Argon2ChallengeConfig;
                    break;
                case ChallengeStrategy.TargetNumber:
                    challenge_config = {
                        algorithm: ChallengeAlgorithm.Argon2id,
                        strategy: ChallengeStrategy.TargetNumber,
                        difficulty: config.target_number.max_number,
                        parameters: { expires_at: Date.now() + CHALLENGE_TIMEOUT_MS },
                    } as Argon2ChallengeConfig;
                    break;
            }
            break;
        case ChallengeAlgorithm.kCTF:
            challenge_config = {
                algorithm: ChallengeAlgorithm.kCTF,
                difficulty: config.kctf.difficulty,
                parameters: { expires_at: Date.now() + CHALLENGE_TIMEOUT_MS },
            } as kCTFChallengeConfig;
            break;
    }

    let challenge = await generate_challenge(challenge_config);
    if (challenge === null) {
        throw createError({
            statusCode: 500,
            statusMessage: 'Failed to generate challenge'
        });
    }

    outstandingChallenges.set(challenge.salt, {
        challenge, timeout: setTimeout(() => {
            console.log("Challenge timed out:", challenge.salt);
            outstandingChallenges.delete(challenge.salt);
        }, CHALLENGE_TIMEOUT_MS)
    });

    return {
        challenge,
    }
})