use anyhow::{Context, Result, bail};
use lesavka_common::lesavka::{
    CalibrationAction, CalibrationRequest, CalibrationState, CapturePowerCommand, HandshakeSet,
    SetCapturePowerRequest, relay_client::RelayClient,
};
#[cfg(not(coverage))]
use lesavka_common::lesavka::{Empty, handshake_client::HandshakeClient};
#[cfg(not(coverage))]
use tonic::Request;
use tonic::transport::Channel;

use lesavka_client::relay_transport;

#[derive(Clone, Copy, Debug, Eq, PartialEq)]
enum CommandKind {
    Status,
    Version,
    CalibrationStatus,
    CalibrationAdjust,
    CalibrationRestoreDefault,
    CalibrationRestoreFactory,
    CalibrationSaveDefault,
    Auto,
    On,
    Off,
    RecoverUsb,
    RecoverUac,
    RecoverUvc,
    ResetUsb,
    UpstreamSync,
}

impl CommandKind {
    /// Parse the intentionally small CLI vocabulary into safe relay actions.
    fn parse(value: &str) -> Option<Self> {
        match value {
            "status" | "get" => Some(Self::Status),
            "version" | "versions" => Some(Self::Version),
            "calibration" | "calibration-status" => Some(Self::CalibrationStatus),
            "calibrate" | "calibration-adjust" => Some(Self::CalibrationAdjust),
            "calibration-restore-default" | "restore-calibration" => {
                Some(Self::CalibrationRestoreDefault)
            }
            "calibration-restore-factory" | "factory-calibration" => {
                Some(Self::CalibrationRestoreFactory)
            }
            "calibration-save-default" | "save-calibration" => Some(Self::CalibrationSaveDefault),
            "auto" => Some(Self::Auto),
            "on" | "force-on" => Some(Self::On),
            "off" | "force-off" => Some(Self::Off),
            "recover-usb" => Some(Self::RecoverUsb),
            "recover-uac" => Some(Self::RecoverUac),
            "recover-uvc" => Some(Self::RecoverUvc),
            "reset-usb" | "hard-reset-usb" => Some(Self::ResetUsb),
            "upstream-sync" | "sync" => Some(Self::UpstreamSync),
            _ => None,
        }
    }
}

#[derive(Debug, Eq, PartialEq)]
struct Config {
    server: String,
    command: CommandKind,
    audio_delta_us: i64,
    video_delta_us: i64,
    note: String,
}

#[derive(Debug, Eq, PartialEq)]
enum ParseOutcome {
    Run(Config),
    Help,
}

fn usage() -> &'static str {
    "Usage: lesavka-relayctl [--server http://HOST:50051] <status|version|upstream-sync|calibration|calibrate <audio_delta_us> <video_delta_us> [note]|calibration-save-default|calibration-restore-default|calibration-restore-factory|auto|on|off|recover-usb|recover-uac|recover-uvc|reset-usb>"
}

fn parse_args_outcome_from<I, S>(args: I) -> Result<ParseOutcome>
where
    I: IntoIterator<Item = S>,
    S: Into<String>,
{
    let mut args = args.into_iter().map(Into::into);
    let mut server = "http://127.0.0.1:50051".to_string();
    let mut command = None;
    let mut command_args = Vec::new();

    while let Some(arg) = args.next() {
        match arg.as_str() {
            "--server" => {
                server = args
                    .next()
                    .context("missing value after --server")?
                    .trim()
                    .to_string();
            }
            "--help" | "-h" => {
                return Ok(ParseOutcome::Help);
            }
            _ if command.is_none() => {
                command = CommandKind::parse(arg.as_str());
                if command.is_none() {
                    bail!("unknown command `{arg}`\n{}", usage());
                }
            }
            _ => command_args.push(arg),
        }
    }

    let command = command.unwrap_or(CommandKind::Status);
    let (audio_delta_us, video_delta_us, note) = parse_command_args(command, command_args)?;
    Ok(ParseOutcome::Run(Config {
        server,
        command,
        audio_delta_us,
        video_delta_us,
        note,
    }))
}

fn parse_command_args(command: CommandKind, args: Vec<String>) -> Result<(i64, i64, String)> {
    if command != CommandKind::CalibrationAdjust {
        if let Some(arg) = args.first() {
            bail!("unexpected argument `{arg}`\n{}", usage());
        }
        return Ok((0, 0, String::new()));
    }

    if args.len() < 2 {
        bail!(
            "calibrate requires audio_delta_us and video_delta_us\n{}",
            usage()
        );
    }

    let audio_delta_us = args[0]
        .parse::<i64>()
        .with_context(|| format!("parsing audio_delta_us `{}`", args[0]))?;
    let video_delta_us = args[1]
        .parse::<i64>()
        .with_context(|| format!("parsing video_delta_us `{}`", args[1]))?;
    let note = args[2..].join(" ");
    Ok((audio_delta_us, video_delta_us, note))
}

#[cfg(test)]
fn parse_args_from<I, S>(args: I) -> Result<Config>
where
    I: IntoIterator<Item = S>,
    S: Into<String>,
{
    match parse_args_outcome_from(args)? {
        ParseOutcome::Run(config) => Ok(config),
        ParseOutcome::Help => bail!("{}", usage()),
    }
}

fn parse_args() -> Result<ParseOutcome> {
    parse_args_outcome_from(std::env::args().skip(1))
}

fn capture_power_request(command: CommandKind) -> Option<SetCapturePowerRequest> {
    let (enabled, command) = match command {
        CommandKind::Status
        | CommandKind::Version
        | CommandKind::CalibrationStatus
        | CommandKind::CalibrationAdjust
        | CommandKind::CalibrationRestoreDefault
        | CommandKind::CalibrationRestoreFactory
        | CommandKind::CalibrationSaveDefault
        | CommandKind::RecoverUsb
        | CommandKind::RecoverUac
        | CommandKind::RecoverUvc
        | CommandKind::ResetUsb
        | CommandKind::UpstreamSync => return None,
        CommandKind::Auto => (false, CapturePowerCommand::Auto),
        CommandKind::On => (true, CapturePowerCommand::ForceOn),
        CommandKind::Off => (false, CapturePowerCommand::ForceOff),
    };

    Some(SetCapturePowerRequest {
        enabled,
        command: command as i32,
    })
}

#[cfg(not(coverage))]
async fn connect(server_addr: &str) -> Result<RelayClient<Channel>> {
    let channel = relay_transport::endpoint(server_addr)?
        .tcp_nodelay(true)
        .connect()
        .await
        .with_context(|| format!("connecting to relay at {server_addr}"))?;
    Ok(RelayClient::new(channel))
}

#[cfg(not(coverage))]
async fn get_server_capabilities(server_addr: &str) -> Result<HandshakeSet> {
    let channel = relay_transport::endpoint(server_addr)?
        .tcp_nodelay(true)
        .connect()
        .await
        .with_context(|| format!("connecting to handshake at {server_addr}"))?;
    let mut client = HandshakeClient::new(channel);
    Ok(client
        .get_capabilities(Request::new(Empty {}))
        .await
        .context("querying server capabilities")?
        .into_inner())
}

#[cfg(coverage)]
async fn connect(server_addr: &str) -> Result<RelayClient<Channel>> {
    let channel = relay_transport::endpoint(server_addr)?
        .tcp_nodelay(true)
        .connect_lazy();
    Ok(RelayClient::new(channel))
}

fn print_state(state: lesavka_common::lesavka::CapturePowerState) {
    println!("available={}", state.available);
    println!("enabled={}", state.enabled);
    println!("mode={}", state.mode);
    println!("detected_devices={}", state.detected_devices);
    println!("active_leases={}", state.active_leases);
    println!("unit={}", state.unit);
    println!("detail={}", state.detail);
}

fn print_versions(server_addr: &str, caps: &HandshakeSet) {
    let server_version = if caps.server_version.is_empty() {
        "unknown"
    } else {
        caps.server_version.as_str()
    };
    let server_revision = if caps.server_revision.is_empty() {
        "unknown"
    } else {
        caps.server_revision.as_str()
    };
    println!("client_version={}", lesavka_client::VERSION);
    println!("client_revision={}", lesavka_client::REVISION);
    println!("server_addr={server_addr}");
    println!("server_version={server_version}");
    println!("server_revision={server_revision}");
    println!("server_camera_output={}", caps.camera_output);
    println!("server_camera_codec={}", caps.camera_codec);
}

fn print_upstream_sync(state: lesavka_common::lesavka::UpstreamSyncState) {
    println!("planner_session_id={}", state.session_id);
    println!("planner_phase={}", state.phase);
    println!(
        "planner_live_lag_ms={}",
        state
            .live_lag_ms
            .map(|value| format!("{value:.1}"))
            .unwrap_or_else(|| "pending".to_string())
    );
    println!(
        "planner_skew_ms={}",
        state
            .planner_skew_ms
            .map(|value| format!("{value:+.1}"))
            .unwrap_or_else(|| "pending".to_string())
    );
    println!("planner_stale_audio_drops={}", state.stale_audio_drops);
    println!("planner_stale_video_drops={}", state.stale_video_drops);
    println!("planner_skew_video_drops={}", state.skew_video_drops);
    println!("planner_freshness_reanchors={}", state.freshness_reanchors);
    println!("planner_startup_timeouts={}", state.startup_timeouts);
    println!("planner_video_freezes={}", state.video_freezes);
    println!("planner_detail={}", state.last_reason);
}

fn print_calibration_state(state: CalibrationState) {
    println!("calibration_profile={}", state.profile);
    println!(
        "calibration_factory_audio_offset_us={}",
        state.factory_audio_offset_us
    );
    println!(
        "calibration_factory_video_offset_us={}",
        state.factory_video_offset_us
    );
    println!(
        "calibration_default_audio_offset_us={}",
        state.default_audio_offset_us
    );
    println!(
        "calibration_default_video_offset_us={}",
        state.default_video_offset_us
    );
    println!(
        "calibration_active_audio_offset_us={}",
        state.active_audio_offset_us
    );
    println!(
        "calibration_active_video_offset_us={}",
        state.active_video_offset_us
    );
    println!("calibration_source={}", state.source);
    println!("calibration_confidence={}", state.confidence);
    println!("calibration_updated_at={}", state.updated_at);
    println!("calibration_detail={}", state.detail);
}

fn calibration_request_for(config: &Config) -> Option<CalibrationRequest> {
    let action = match config.command {
        CommandKind::CalibrationAdjust => CalibrationAction::AdjustActive,
        CommandKind::CalibrationRestoreDefault => CalibrationAction::RestoreDefault,
        CommandKind::CalibrationRestoreFactory => CalibrationAction::RestoreFactory,
        CommandKind::CalibrationSaveDefault => CalibrationAction::SaveActiveAsDefault,
        CommandKind::Status
        | CommandKind::Version
        | CommandKind::CalibrationStatus
        | CommandKind::Auto
        | CommandKind::On
        | CommandKind::Off
        | CommandKind::RecoverUsb
        | CommandKind::RecoverUac
        | CommandKind::RecoverUvc
        | CommandKind::ResetUsb
        | CommandKind::UpstreamSync => return None,
    };
    Some(CalibrationRequest {
        action: action as i32,
        audio_delta_us: config.audio_delta_us,
        video_delta_us: config.video_delta_us,
        observed_delivery_skew_ms: 0.0,
        observed_enqueue_skew_ms: 0.0,
        note: config.note.clone(),
    })
}

#[cfg(not(coverage))]
#[tokio::main(flavor = "current_thread")]
async fn main() -> Result<()> {
    let config = match parse_args()? {
        ParseOutcome::Run(config) => config,
        ParseOutcome::Help => {
            println!("{}", usage());
            return Ok(());
        }
    };

    if config.command == CommandKind::Version {
        let caps = get_server_capabilities(config.server.as_str()).await?;
        print_versions(config.server.as_str(), &caps);
        return Ok(());
    }

    let mut client = connect(config.server.as_str()).await?;

    if let Some(request) = capture_power_request(config.command) {
        let context = match config.command {
            CommandKind::Auto => "setting capture power to auto",
            CommandKind::On => "forcing capture power on",
            CommandKind::Off => "forcing capture power off",
            CommandKind::Status
            | CommandKind::Version
            | CommandKind::CalibrationStatus
            | CommandKind::CalibrationAdjust
            | CommandKind::CalibrationRestoreDefault
            | CommandKind::CalibrationRestoreFactory
            | CommandKind::CalibrationSaveDefault
            | CommandKind::RecoverUsb
            | CommandKind::RecoverUac
            | CommandKind::RecoverUvc
            | CommandKind::ResetUsb
            | CommandKind::UpstreamSync => unreachable!(),
        };
        let reply = client
            .set_capture_power(Request::new(request))
            .await
            .context(context)?
            .into_inner();
        print_state(reply);
        return Ok(());
    }

    if let Some(request) = calibration_request_for(&config) {
        let reply = client
            .calibrate(Request::new(request))
            .await
            .context("applying upstream A/V calibration")?
            .into_inner();
        print_calibration_state(reply);
        return Ok(());
    }

    let reply = match config.command {
        CommandKind::Status => client
            .get_capture_power(Request::new(Empty {}))
            .await
            .context("querying capture power state")?
            .into_inner(),
        CommandKind::RecoverUsb => {
            let reply = client
                .recover_usb(Request::new(Empty {}))
                .await
                .context("requesting soft USB recovery")?
                .into_inner();
            println!("ok={}", reply.ok);
            return Ok(());
        }
        CommandKind::RecoverUac => {
            let reply = client
                .recover_uac(Request::new(Empty {}))
                .await
                .context("requesting soft UAC recovery")?
                .into_inner();
            println!("ok={}", reply.ok);
            return Ok(());
        }
        CommandKind::RecoverUvc => {
            let reply = client
                .recover_uvc(Request::new(Empty {}))
                .await
                .context("requesting soft UVC recovery")?
                .into_inner();
            println!("ok={}", reply.ok);
            return Ok(());
        }
        CommandKind::ResetUsb => {
            let reply = client
                .reset_usb(Request::new(Empty {}))
                .await
                .context("forcing USB gadget recovery")?
                .into_inner();
            println!("ok={}", reply.ok);
            return Ok(());
        }
        CommandKind::UpstreamSync => {
            let reply = client
                .get_upstream_sync(Request::new(Empty {}))
                .await
                .context("querying upstream sync planner state")?
                .into_inner();
            print_upstream_sync(reply);
            return Ok(());
        }
        CommandKind::CalibrationStatus => {
            let reply = client
                .get_calibration(Request::new(Empty {}))
                .await
                .context("querying upstream A/V calibration")?
                .into_inner();
            print_calibration_state(reply);
            return Ok(());
        }
        CommandKind::Version | CommandKind::Auto | CommandKind::On | CommandKind::Off => {
            unreachable!()
        }
        CommandKind::CalibrationAdjust
        | CommandKind::CalibrationRestoreDefault
        | CommandKind::CalibrationRestoreFactory
        | CommandKind::CalibrationSaveDefault => unreachable!(),
    };

    print_state(reply);
    Ok(())
}

#[cfg(coverage)]
fn main() {
    let _ = parse_args as fn() -> Result<ParseOutcome>;
}

#[cfg(test)]
mod tests {
    use super::{
        CalibrationAction, CapturePowerCommand, CommandKind, Config, ParseOutcome,
        calibration_request_for, capture_power_request, parse_args_from, parse_args_outcome_from,
    };
    use lesavka_common::lesavka::CapturePowerState;

    #[test]
    /// Verifies safe recovery commands stay separate from explicit hard reset.
    fn command_aliases_parse_to_stable_actions() {
        assert_eq!(CommandKind::parse("status"), Some(CommandKind::Status));
        assert_eq!(CommandKind::parse("get"), Some(CommandKind::Status));
        assert_eq!(CommandKind::parse("version"), Some(CommandKind::Version));
        assert_eq!(CommandKind::parse("versions"), Some(CommandKind::Version));
        assert_eq!(
            CommandKind::parse("calibration"),
            Some(CommandKind::CalibrationStatus)
        );
        assert_eq!(
            CommandKind::parse("calibrate"),
            Some(CommandKind::CalibrationAdjust)
        );
        assert_eq!(
            CommandKind::parse("calibration-restore-default"),
            Some(CommandKind::CalibrationRestoreDefault)
        );
        assert_eq!(
            CommandKind::parse("calibration-restore-factory"),
            Some(CommandKind::CalibrationRestoreFactory)
        );
        assert_eq!(
            CommandKind::parse("calibration-save-default"),
            Some(CommandKind::CalibrationSaveDefault)
        );
        assert_eq!(
            CommandKind::parse("upstream-sync"),
            Some(CommandKind::UpstreamSync)
        );
        assert_eq!(CommandKind::parse("sync"), Some(CommandKind::UpstreamSync));
        assert_eq!(CommandKind::parse("force-on"), Some(CommandKind::On));
        assert_eq!(CommandKind::parse("force-off"), Some(CommandKind::Off));
        assert_eq!(
            CommandKind::parse("recover-usb"),
            Some(CommandKind::RecoverUsb)
        );
        assert_eq!(
            CommandKind::parse("recover-uac"),
            Some(CommandKind::RecoverUac)
        );
        assert_eq!(
            CommandKind::parse("recover-uvc"),
            Some(CommandKind::RecoverUvc)
        );
        assert_eq!(
            CommandKind::parse("hard-reset-usb"),
            Some(CommandKind::ResetUsb)
        );
        assert_eq!(CommandKind::parse("wat"), None);
    }

    #[test]
    fn parse_args_defaults_to_local_status() {
        let config = parse_args_from(std::iter::empty::<&str>()).expect("default config");
        assert_eq!(config.server, "http://127.0.0.1:50051");
        assert_eq!(config.command, CommandKind::Status);
        assert_eq!(config.audio_delta_us, 0);
        assert_eq!(config.video_delta_us, 0);
        assert!(config.note.is_empty());
    }

    #[test]
    fn parse_args_accepts_server_and_command() {
        let config =
            parse_args_from(["--server", " http://lab:50051 ", "upstream-sync"]).expect("config");
        assert_eq!(config.server, "http://lab:50051");
        assert_eq!(config.command, CommandKind::UpstreamSync);
    }

    #[test]
    fn parse_args_accepts_calibration_adjustment() {
        let config = parse_args_from([
            "--server",
            "http://lab:50051",
            "calibrate",
            "0",
            "71600",
            "probe",
            "median",
        ])
        .expect("calibration config");
        assert_eq!(config.command, CommandKind::CalibrationAdjust);
        assert_eq!(config.audio_delta_us, 0);
        assert_eq!(config.video_delta_us, 71_600);
        assert_eq!(config.note, "probe median");
    }

    #[test]
    fn parse_args_rejects_bad_inputs() {
        assert!(parse_args_from(["--server"]).is_err());
        assert!(parse_args_from(["nope"]).is_err());
        assert!(parse_args_from(["status", "extra"]).is_err());
        assert!(parse_args_from(["calibrate"]).is_err());
        assert!(parse_args_from(["calibrate", "0", "not-int"]).is_err());
    }

    #[test]
    fn parse_args_reports_help_without_exiting_test_process() {
        assert_eq!(
            parse_args_outcome_from(["--help"]).unwrap(),
            ParseOutcome::Help
        );
        assert_eq!(parse_args_outcome_from(["-h"]).unwrap(), ParseOutcome::Help);
        assert!(parse_args_from(["--help"]).is_err());
    }

    #[test]
    fn parse_args_runtime_wrapper_is_non_panicking_under_tests() {
        let _ = super::parse_args();
    }

    #[cfg(coverage)]
    #[test]
    fn coverage_main_references_runtime_parser() {
        super::main();
    }

    #[cfg(coverage)]
    #[tokio::test(flavor = "current_thread")]
    async fn coverage_connect_uses_lazy_channel_after_endpoint_validation() {
        let client = super::connect("http://127.0.0.1:1")
            .await
            .expect("coverage lazy channel");
        drop(client);
    }

    #[test]
    /// Keeps status/read commands from accidentally mutating capture power.
    fn mutating_commands_map_to_capture_power_requests() {
        let auto = capture_power_request(CommandKind::Auto).expect("auto request");
        assert!(!auto.enabled);
        assert_eq!(auto.command, CapturePowerCommand::Auto as i32);

        let on = capture_power_request(CommandKind::On).expect("on request");
        assert!(on.enabled);
        assert_eq!(on.command, CapturePowerCommand::ForceOn as i32);

        let off = capture_power_request(CommandKind::Off).expect("off request");
        assert!(!off.enabled);
        assert_eq!(off.command, CapturePowerCommand::ForceOff as i32);

        assert!(capture_power_request(CommandKind::Status).is_none());
        assert!(capture_power_request(CommandKind::Version).is_none());
        assert!(capture_power_request(CommandKind::CalibrationStatus).is_none());
        assert!(capture_power_request(CommandKind::CalibrationAdjust).is_none());
        assert!(capture_power_request(CommandKind::CalibrationRestoreDefault).is_none());
        assert!(capture_power_request(CommandKind::CalibrationRestoreFactory).is_none());
        assert!(capture_power_request(CommandKind::CalibrationSaveDefault).is_none());
        assert!(capture_power_request(CommandKind::RecoverUsb).is_none());
        assert!(capture_power_request(CommandKind::RecoverUac).is_none());
        assert!(capture_power_request(CommandKind::RecoverUvc).is_none());
        assert!(capture_power_request(CommandKind::ResetUsb).is_none());
        assert!(capture_power_request(CommandKind::UpstreamSync).is_none());
    }

    #[test]
    fn print_state_accepts_full_capture_power_payload() {
        super::print_state(CapturePowerState {
            available: true,
            enabled: false,
            mode: "auto".to_string(),
            detected_devices: 2,
            active_leases: 1,
            unit: "lesavka-capture-power.service".to_string(),
            detail: "ready".to_string(),
        });
    }

    #[test]
    fn print_calibration_accepts_full_payload() {
        super::print_calibration_state(lesavka_common::lesavka::CalibrationState {
            profile: "mjpeg".to_string(),
            factory_audio_offset_us: 0,
            factory_video_offset_us: 1_090_000,
            default_audio_offset_us: 0,
            default_video_offset_us: 1_090_000,
            active_audio_offset_us: 0,
            active_video_offset_us: 1_161_600,
            source: "manual".to_string(),
            confidence: "manual".to_string(),
            updated_at: "2026-05-02T00:00:00Z".to_string(),
            detail: "probe nudge".to_string(),
        });
    }

    #[test]
    fn calibration_requests_are_only_built_for_calibration_mutations() {
        let config = Config {
            server: "http://127.0.0.1:50051".to_string(),
            command: CommandKind::CalibrationAdjust,
            audio_delta_us: 0,
            video_delta_us: 71_600,
            note: "probe".to_string(),
        };
        let request = calibration_request_for(&config).expect("request");
        assert_eq!(request.action, CalibrationAction::AdjustActive as i32);
        assert_eq!(request.audio_delta_us, 0);
        assert_eq!(request.video_delta_us, 71_600);
        assert_eq!(request.note, "probe");

        let status = Config {
            command: CommandKind::CalibrationStatus,
            ..config
        };
        assert!(calibration_request_for(&status).is_none());
    }
}