use crate::config::Config;
use crate::gandi::GandiAPI;
use crate::ip_source::{ip_source::IPSource, ipify::IPSourceIpify};
use clap::Parser;
use config::IPSourceName;
use ip_source::icanhazip::IPSourceIcanhazip;
use opts::Opts;
use reqwest::{header, Client, ClientBuilder, StatusCode};
use serde::Serialize;
use std::{num::NonZeroU32, sync::Arc, time::Duration};
use tokio::join;
use tokio::{self, task::JoinHandle, time::sleep};
mod config;
mod gandi;
mod ip_source;
mod opts;
use die_exit::*;

/// 30 requests per minute, see https://api.gandi.net/docs/reference/
const GANDI_RATE_LIMIT: u32 = 30;
/// If we hit the rate limit, wait up to this many seconds before next attempt
const GANDI_DELAY_JITTER: u64 = 20;

fn api_client(api_key: &str) -> anyhow::Result<Client> {
    let client_builder = ClientBuilder::new();

    let key = format!("Apikey {}", api_key);
    let mut auth_value = header::HeaderValue::from_str(&key)?;
    let mut headers = header::HeaderMap::new();
    auth_value.set_sensitive(true);
    headers.insert(header::AUTHORIZATION, auth_value);
    let accept_value = header::HeaderValue::from_static("application/json");
    headers.insert(header::ACCEPT, accept_value);
    let client = client_builder.default_headers(headers).build()?;
    Ok(client)
}

#[derive(Serialize)]
pub struct APIPayload {
    pub rrset_values: Vec<String>,
    pub rrset_ttl: u32,
}

async fn run(
    base_url: &str,
    ip_source: &Box<dyn IPSource>,
    conf: &Config,
    opts: &Opts,
) -> anyhow::Result<()> {
    let mut last_ipv4: Option<String> = None;
    let mut last_ipv6: Option<String> = None;

    loop {
        println!("Finding out the IP address...");
        let (ipv4_result, ipv6_result) = join!(ip_source.get_ipv4(), ip_source.get_ipv6());
        let ipv4 = ipv4_result.as_ref();
        let ipv6 = ipv6_result.as_ref();
        println!("Found these:");
        match ipv4 {
            Ok(ip) => println!("\tIPv4: {}", ip),
            Err(err) => eprintln!("\tIPv4 failed: {}", err),
        }
        match ipv6 {
            Ok(ip) => println!("\tIPv6: {}", ip),
            Err(err) => eprintln!("\tIPv6 failed: {}", err),
        }

        let ipv4_same = last_ipv4
            .as_ref()
            .map(|p| ipv4.map(|q| p == q).unwrap_or(false))
            .unwrap_or(false);
        let ipv6_same = last_ipv6
            .as_ref()
            .map(|p| ipv6.map(|q| p == q).unwrap_or(false))
            .unwrap_or(false);

        last_ipv4 = ipv4.ok().map(|v| v.to_string());
        last_ipv6 = ipv6.ok().map(|v| v.to_string());

        if !ipv4_same || !ipv6_same || conf.always_update {
            let client = api_client(&conf.api_key)?;
            let mut tasks: Vec<JoinHandle<(StatusCode, String)>> = Vec::new();
            println!("Attempting to update DNS entries now");

            let governor = Arc::new(governor::RateLimiter::direct(governor::Quota::per_minute(
                NonZeroU32::new(GANDI_RATE_LIMIT).die("Governor rate is 0"),
            )));
            let retry_jitter =
                governor::Jitter::new(Duration::ZERO, Duration::from_secs(GANDI_DELAY_JITTER));

            for entry in &conf.entry {
                for entry_type in Config::types(entry) {
                    let fqdn = Config::fqdn(entry, conf).to_string();
                    let url = GandiAPI {
                        fqdn: &fqdn,
                        rrset_name: &entry.name,
                        rrset_type: entry_type,
                        base_url,
                    }
                    .url();
                    let ip = match entry_type {
                        "A" => ipv4.die_with(|error| format!("Needed IPv4 for {fqdn}: {error}")),
                        "AAAA" => ipv6.die_with(|error| format!("Needed IPv6 for {fqdn}: {error}")),
                        bad_entry_type => die!("Unexpected type in config: {}", bad_entry_type),
                    };
                    let payload = APIPayload {
                        rrset_values: vec![ip.to_string()],
                        rrset_ttl: Config::ttl(entry, conf),
                    };
                    let req = client.put(url).json(&payload);
                    let task_governor = governor.clone();
                    let entry_type = entry_type.to_string();
                    let task = tokio::task::spawn(async move {
                        task_governor.until_ready_with_jitter(retry_jitter).await;
                        println!("Updating {} record for {}", entry_type, &fqdn);
                        match req.send().await {
                            Ok(response) => (
                                response.status(),
                                response
                                    .text()
                                    .await
                                    .unwrap_or_else(|error| error.to_string()),
                            ),
                            Err(error) => (StatusCode::IM_A_TEAPOT, error.to_string()),
                        }
                    });
                    tasks.push(task);
                }
            }

            let results = futures::future::try_join_all(tasks).await?;
            println!("Updates done for {} entries", results.len());
            for (status, body) in results {
                println!("{} - {}", status, body);
            }
        } else {
            println!("IP address has not changed since last update");
        }

        if let Some(repeat) = opts.repeat {
            // If configured to repeat, do so
            sleep(Duration::from_secs(repeat)).await;
            continue;
        }
        // Otherwise this is one-shot, we should exit now
        break;
    }

    Ok(())
}

#[tokio::main(flavor = "current_thread")]
async fn main() -> anyhow::Result<()> {
    let opts = opts::Opts::parse();
    let conf = config::load_config(&opts)
        .die_with(|error| format!("Failed to read config file: {}", error));

    let ip_source: Box<dyn IPSource> = match conf.ip_source {
        IPSourceName::Ipify => Box::new(IPSourceIpify),
        IPSourceName::Icanhazip => Box::new(IPSourceIcanhazip),
    };
    config::validate_config(&conf).die_with(|error| format!("Invalid config: {}", error));
    run("https://api.gandi.net", &ip_source, &conf, &opts).await?;
    Ok(())
}

#[cfg(test)]
mod tests {
    use std::{env::temp_dir, time::Duration};

    use crate::{config, ip_source::ip_source::IPSource, opts::Opts, run};
    use async_trait::async_trait;
    use httpmock::MockServer;
    use tokio::{fs, task::LocalSet, time::sleep};

    struct IPSourceMock;

    #[async_trait]
    impl IPSource for IPSourceMock {
        async fn get_ipv4(&self) -> anyhow::Result<String> {
            Ok("192.168.0.0".to_string())
        }
        async fn get_ipv6(&self) -> anyhow::Result<String> {
            Ok("fe80:0000:0208:74ff:feda:625c".to_string())
        }
    }

    #[tokio::test]
    async fn single_shot() {
        let mut temp = temp_dir().join("gandi-live-dns-test");
        fs::create_dir_all(&temp)
            .await
            .expect("Failed to create test dir");
        temp.push("test.toml");
        fs::write(
            &temp,
            "fqdn = \"example.com\"\napi_key = \"xxx\"\nttl = 300\n[[entry]]\nname =\"@\"\n",
        )
        .await
        .expect("Failed to write test config file");
        let fqdn = "example.com";
        let rname = "@";
        let rtype = "A";
        let server = MockServer::start();
        let mock = server.mock(|when, then| {
            when.method("PUT")
                .path(format!(
                    "/v5/livedns/domains/{fqdn}/records/{rname}/{rtype}"
                ))
                .body_contains("192.168.0.0");
            then.status(200);
        });

        let opts = Opts {
            config: Some(temp.to_string_lossy().to_string()),
            ..Opts::default()
        };
        let conf = config::load_config(&opts).expect("Failed to load config");
        let ip_source: Box<dyn IPSource> = Box::new(IPSourceMock);
        run(server.base_url().as_str(), &ip_source, &conf, &opts)
            .await
            .expect("Failed when running the update");

        // Assert
        mock.assert();
    }

    #[test]
    fn repeat() {
        let runtime = tokio::runtime::Builder::new_current_thread()
            .enable_all()
            .build()
            .unwrap();

        LocalSet::new().block_on(&runtime, async {
            let mut temp = temp_dir().join("gandi-live-dns-test");
            fs::create_dir_all(&temp)
                .await
                .expect("Failed to create test dir");
            temp.push("test.toml");
            fs::write(
                &temp,
                "fqdn = \"example.com\"\napi_key = \"xxx\"\nttl = 300\n[[entry]]\nname =\"@\"\n",
            )
            .await
            .expect("Failed to write test config file");

            let fqdn = "example.com";
            let rname = "@";
            let rtype = "A";
            let server = MockServer::start();
            let mock = server.mock(|when, then| {
                when.method("PUT")
                    .path(format!(
                        "/v5/livedns/domains/{fqdn}/records/{rname}/{rtype}"
                    ))
                    .body_contains("192.168.0.0");
                then.status(200);
            });

            let server_url = server.base_url();
            let handle = tokio::task::spawn_local(async move {
                let opts = Opts {
                    config: Some(temp.to_string_lossy().to_string()),
                    repeat: Some(1),
                    ..Opts::default()
                };
                let conf = config::load_config(&opts).expect("Failed to load config");
                let ip_source: Box<dyn IPSource> = Box::new(IPSourceMock);
                run(&server_url, &ip_source, &conf, &opts)
                    .await
                    .expect("Failed when running the update");
            });

            sleep(Duration::from_secs(3)).await;
            handle.abort();

            // Only should update once because the IP doesn't change
            mock.assert();
        });
    }

    #[test]
    fn repeat_always_update() {
        let runtime = tokio::runtime::Builder::new_current_thread()
            .enable_all()
            .build()
            .unwrap();

        LocalSet::new().block_on(&runtime, async {
            let mut temp = temp_dir().join("gandi-live-dns-test");
            fs::create_dir_all(&temp)
                .await
                .expect("Failed to create test dir");
            temp.push("test.toml");
            fs::write(
                &temp,
                "fqdn = \"example.com\"\nalways_update = true\napi_key = \"xxx\"\nttl = 300\n[[entry]]\nname =\"@\"\n",
            )
            .await
            .expect("Failed to write test config file");

            let fqdn = "example.com";
            let rname = "@";
            let rtype = "A";
            let server = MockServer::start();
            let mock = server.mock(|when, then| {
                when.method("PUT")
                    .path(format!(
                        "/v5/livedns/domains/{fqdn}/records/{rname}/{rtype}"
                    ))
                    .body_contains("192.168.0.0");
                then.status(200);
            });

            let server_url = server.base_url();
            let handle = tokio::task::spawn_local(async move {
                let opts = Opts {
                    config: Some(temp.to_string_lossy().to_string()),
                    repeat: Some(1),
                    ..Opts::default()
                };
                let conf = config::load_config(&opts).expect("Failed to load config");
                let ip_source: Box<dyn IPSource> = Box::new(IPSourceMock);
                run(&server_url, &ip_source, &conf, &opts)
                    .await
                    .expect("Failed when running the update");
            });

            sleep(Duration::from_secs(3)).await;
            handle.abort();

            // Should update multiple times since always_update
            assert!(mock.hits() > 1);
        });
    }
}