// Copyright (C) 2022  Aravinth Manivannan <realaravinth@batsense.net>
// SPDX-FileCopyrightText: 2023 Aravinth Manivannan <realaravinth@batsense.net>
//
// SPDX-License-Identifier: AGPL-3.0-or-later

//use actix::prelude::*;
use actix_web::{web, HttpResponse, Responder};
use libmcaptcha::pow::PoWConfig;
use libmcaptcha::{
    defense::LevelBuilder, master::messages::AddSiteBuilder, DefenseBuilder,
    MCaptchaBuilder,
};
use serde::{Deserialize, Serialize};

use crate::errors::*;
//use crate::stats::record::record_fetch;
use crate::AppData;
use crate::V1_API_ROUTES;

#[derive(Clone, Debug, Deserialize, Serialize)]
pub struct GetConfigPayload {
    pub key: String,
}

#[derive(Clone, Serialize, Deserialize, Debug)]
pub struct ApiPoWConfig {
    pub string: String,
    pub difficulty_factor: u32,
    pub salt: String,
    pub max_recorded_nonce: u32,
}

/// get PoW configuration for an mcaptcha key
#[my_codegen::post(path = "V1_API_ROUTES.pow.get_config()")]
pub async fn get_config(
    payload: web::Json<GetConfigPayload>,
    data: AppData,
) -> ServiceResult<impl Responder> {
    //if res.exists.is_none() {
    if !data.db.captcha_exists(None, &payload.key).await? {
        return Err(ServiceError::TokenNotFound);
    }
    let payload = payload.into_inner();

    let config: ServiceResult<PoWConfig> =
        match data.captcha.get_pow(payload.key.clone()).await {
            Ok(Some(config)) => Ok(config),
            Ok(None) => {
                init_mcaptcha(&data, &payload.key).await?;
                let config = data
                    .captcha
                    .get_pow(payload.key.clone())
                    .await
                    .expect("mcaptcha should be initialized and ready to go");
                Ok(config.unwrap())
            }
            Err(e) => Err(e.into()),
        };
    let config = config?;
    let max_nonce = data
        .db
        .get_max_nonce_for_level(&payload.key, config.difficulty_factor)
        .await?;
    data.stats.record_fetch(&data, &payload.key).await?;

    let config = ApiPoWConfig {
        string: config.string,
        difficulty_factor: config.difficulty_factor,
        salt: config.salt,
        max_recorded_nonce: max_nonce,
    };
    Ok(HttpResponse::Ok().json(config))
}
/// Call this when [MCaptcha][libmcaptcha::MCaptcha] is not in master.
///
/// This fn gets mcaptcha config from database, builds [Defense][libmcaptcha::Defense],
/// creates [MCaptcha][libmcaptcha::MCaptcha] and adds it to [Master][libmcaptcha::Defense]
pub async fn init_mcaptcha(data: &AppData, key: &str) -> ServiceResult<()> {
    println!("Initializing captcha");
    // get levels
    let levels = data.db.get_captcha_levels(None, key).await?;
    let duration = data.db.get_captcha_cooldown(key).await?;

    // build defense
    let mut defense = DefenseBuilder::default();

    for level in levels.iter() {
        let level = LevelBuilder::default()
            .visitor_threshold(level.visitor_threshold)
            .difficulty_factor(level.difficulty_factor)
            .unwrap()
            .build()
            .unwrap();
        defense.add_level(level).unwrap();
    }

    let defense = defense.build()?;
    println!("{:?}", defense);

    // create captcha
    let mcaptcha = MCaptchaBuilder::default()
        .defense(defense)
        // leaky bucket algorithm's emission interval
        .duration(duration as u64)
        //   .cache(cache)
        .build()
        .unwrap();

    // add captcha to master
    let msg = AddSiteBuilder::default()
        .id(key.into())
        .mcaptcha(mcaptcha)
        .build()
        .unwrap();

    data.captcha.add_site(msg).await?;

    Ok(())
}

#[cfg(test)]
pub mod tests {
    use crate::*;
    use libmcaptcha::pow::PoWConfig;

    #[actix_rt::test]
    async fn get_pow_config_works_pg() {
        let data = crate::tests::pg::get_data().await;
        get_pow_config_works(data).await;
    }

    #[actix_rt::test]
    async fn get_pow_config_works_maria() {
        let data = crate::tests::maria::get_data().await;
        get_pow_config_works(data).await;
    }

    pub async fn get_pow_config_works(data: ArcData) {
        use super::*;
        use crate::tests::*;
        use crate::*;
        use actix_web::test;

        const NAME: &str = "powusrworks";
        const PASSWORD: &str = "testingpas";
        const EMAIL: &str = "randomuser@a.com";

        let data = &data;

        delete_user(data, NAME).await;

        register_and_signin(data, NAME, EMAIL, PASSWORD).await;
        let (_, _signin_resp, token_key) = add_levels_util(data, NAME, PASSWORD).await;
        let app = get_app!(data).await;

        let get_config_payload = GetConfigPayload {
            key: token_key.key.clone(),
        };

        // update and check changes

        let url = V1_API_ROUTES.pow.get_config;
        println!("{}", &url);
        let get_config_resp = test::call_service(
            &app,
            post_request!(&get_config_payload, V1_API_ROUTES.pow.get_config)
                .to_request(),
        )
        .await;
        assert_eq!(get_config_resp.status(), StatusCode::OK);
        let config: PoWConfig = test::read_body_json(get_config_resp).await;
        assert_eq!(config.difficulty_factor, L1.difficulty_factor);
    }

    #[actix_rt::test]
    async fn pow_difficulty_factor_increases_on_visitor_count_increase_pg() {
        let data = crate::tests::pg::get_data().await;
        pow_difficulty_factor_increases_on_visitor_count_increase(data).await;
    }

    #[actix_rt::test]
    async fn pow_difficulty_factor_increases_on_visitor_count_increase_maria() {
        let data = crate::tests::maria::get_data().await;
        pow_difficulty_factor_increases_on_visitor_count_increase(data).await;
    }

    pub async fn pow_difficulty_factor_increases_on_visitor_count_increase(
        data: ArcData,
    ) {
        use super::*;
        use crate::tests::*;
        use crate::*;
        use actix_web::test;

        use libmcaptcha::defense::Level;

        use crate::api::v1::mcaptcha::create::CreateCaptcha;
        use crate::api::v1::mcaptcha::create::MCaptchaDetails;

        const NAME: &str = "powusrworks2";
        const PASSWORD: &str = "testingpas";
        const EMAIL: &str = "randomuser2@a.com";
        pub const L1: Level = Level {
            difficulty_factor: 10,
            visitor_threshold: 10,
        };
        pub const L2: Level = Level {
            difficulty_factor: 20,
            visitor_threshold: 20,
        };

        pub const L3: Level = Level {
            difficulty_factor: 30,
            visitor_threshold: 30,
        };

        let data = &data;
        let levels = [L1, L2, L3];

        delete_user(data, NAME).await;

        let (_, signin_resp) = register_and_signin(data, NAME, EMAIL, PASSWORD).await;
        let cookies = get_cookie!(signin_resp);
        let app = get_app!(data).await;

        let create_captcha = CreateCaptcha {
            levels: levels.into(),
            duration: 30,
            description: "dummy".into(),
            publish_benchmarks: true,
        };

        // 1. add level
        let add_token_resp = test::call_service(
            &app,
            post_request!(&create_captcha, V1_API_ROUTES.captcha.create)
                .cookie(cookies.clone())
                .to_request(),
        )
        .await;
        assert_eq!(add_token_resp.status(), StatusCode::OK);
        let token_key: MCaptchaDetails = test::read_body_json(add_token_resp).await;

        let get_config_payload = GetConfigPayload {
            key: token_key.key.clone(),
        };

        let _url = V1_API_ROUTES.pow.get_config;
        let mut prev = 0;
        for (count, l) in levels.iter().enumerate() {
            for _l in prev..l.visitor_threshold * 2 {
                let _get_config_resp = test::call_service(
                    &app,
                    post_request!(&get_config_payload, V1_API_ROUTES.pow.get_config)
                        .to_request(),
                )
                .await;
            }

            let get_config_resp = test::call_service(
                &app,
                post_request!(&get_config_payload, V1_API_ROUTES.pow.get_config)
                    .to_request(),
            )
            .await;

            let config: PoWConfig = test::read_body_json(get_config_resp).await;
            println!(
                "[{count}] received difficulty_factor: {} prev difficulty_factor {}",
                config.difficulty_factor, prev
            );
            if count == levels.len() - 1 {
                assert!(config.difficulty_factor == prev);
            } else {
                assert!(config.difficulty_factor > prev);
            }
            prev = config.difficulty_factor;
        }
        // update and check changes
    }
}