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//! BWE recovery mechanism tests (AIMD recovery after congestion).
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use std::time::Duration;
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use netem::{DataSize, NetemConfig};
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use str0m::RtcError;
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use str0m::bwe::Bitrate;
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use crate::common::{BweTestContext, Step, connect_with_bwe, init_crypto_default, init_log};
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#[test]
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fn aimd_multiplicative_decrease_on_congestion() -> Result<(), RtcError> {
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    init_log();
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    init_crypto_default();
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    let plan = vec![
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        Step::Conditions {
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            description: "Good network",
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            config: NetemConfig::new()
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                .latency(Duration::from_millis(20))
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                .link(Bitrate::mbps(5), DataSize::kbytes(100))
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                .seed(42),
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        },
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        Step::Media {
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            description: "Send at 2 Mbps",
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            desired_bitrate: Bitrate::mbps(5),
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            media_send_rate: Bitrate::mbps(2),
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        },
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        Step::Run {
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            description: "Establish baseline estimate",
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            duration: Duration::from_secs(5),
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        },
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        Step::Check {
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            description: "Baseline estimate around 2 Mbps",
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            at_least: Bitrate::mbps(2),
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        },
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        // Introduce severe congestion
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        Step::Conditions {
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            description: "High latency causes overuse",
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            config: NetemConfig::new()
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                .latency(Duration::from_millis(150)) // Queuing delay
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                .link(Bitrate::mbps(5), DataSize::kbytes(100))
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                .seed(42),
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        },
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        Step::Run {
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            description: "Wait for overuse detection and AIMD decrease",
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            duration: Duration::from_secs(3),
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        },
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        Step::Check {
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            description: "Estimate dropped via multiplicative decrease",
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            at_least: Bitrate::kbps(500),
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        },
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    ];
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    let (mut l, mut r) = connect_with_bwe(Bitrate::mbps(2), Bitrate::mbps(5));
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    let mut ctx = BweTestContext::new(&mut l, &mut r);
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    ctx.run_plan(&mut l, &mut r, &plan)?;
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    Ok(())
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}
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#[test]
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fn aimd_additive_increase_recovers_estimate() -> Result<(), RtcError> {
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    init_log();
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    init_crypto_default();
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    let plan = vec![
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        Step::Conditions {
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            description: "Good network",
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            config: NetemConfig::new()
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                .latency(Duration::from_millis(20))
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                .link(Bitrate::mbps(5), DataSize::kbytes(100))
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                .seed(42),
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        },
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        Step::Media {
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            description: "Send at 2 Mbps",
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            desired_bitrate: Bitrate::mbps(5),
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            media_send_rate: Bitrate::mbps(2),
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        },
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        Step::Run {
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            description: "Establish baseline",
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            duration: Duration::from_secs(5),
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        },
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        Step::Check {
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            description: "Baseline around 2 Mbps",
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            at_least: Bitrate::mbps(2),
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        },
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        // Cause congestion
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        Step::Conditions {
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            description: "Temporary congestion",
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            config: NetemConfig::new()
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                .latency(Duration::from_millis(150))
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                .link(Bitrate::mbps(5), DataSize::kbytes(100))
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                .seed(42),
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        },
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        Step::Run {
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            description: "Trigger multiplicative decrease",
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            duration: Duration::from_secs(3),
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        },
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        Step::Check {
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            description: "Estimate dropped",
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            at_least: Bitrate::kbps(500),
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        },
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        // Restore good network
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        Step::Conditions {
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            description: "Restore good conditions",
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            config: NetemConfig::new()
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                .latency(Duration::from_millis(20))
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                .link(Bitrate::mbps(5), DataSize::kbytes(100))
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                .seed(42),
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        },
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        Step::Run {
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            description: "Allow AIMD additive increase to recover",
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            duration: Duration::from_secs(10),
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        },
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        Step::Check {
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            description: "Estimate recovers via additive increase",
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            at_least: Bitrate::mbps(1),
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        },
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    ];
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    let (mut l, mut r) = connect_with_bwe(Bitrate::mbps(2), Bitrate::mbps(5));
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    let mut ctx = BweTestContext::new(&mut l, &mut r);
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    ctx.run_plan(&mut l, &mut r, &plan)?;
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    Ok(())
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}
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#[test]
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fn aimd_recovery_reaches_original_estimate() -> Result<(), RtcError> {
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    init_log();
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    init_crypto_default();
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    let plan = vec![
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        Step::Conditions {
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            description: "Good network",
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            config: NetemConfig::new()
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                .latency(Duration::from_millis(20))
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                .link(Bitrate::mbps(3), DataSize::kbytes(100))
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                .seed(42),
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        },
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        Step::Media {
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            description: "Send at 2 Mbps",
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            desired_bitrate: Bitrate::mbps(5),
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            media_send_rate: Bitrate::mbps(2),
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        },
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        Step::Run {
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            description: "Establish baseline",
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            duration: Duration::from_secs(5),
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        },
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        Step::Check {
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            description: "Baseline established",
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            at_least: Bitrate::mbps(2),
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        },
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        // Brief congestion
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        Step::Conditions {
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            description: "Brief congestion event",
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            config: NetemConfig::new()
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                .latency(Duration::from_millis(150))
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                .link(Bitrate::mbps(3), DataSize::kbytes(100))
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                .seed(42),
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        },
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        Step::Run {
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            description: "Drop estimate",
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            duration: Duration::from_secs(2),
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        },
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        // Restore and allow full recovery
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        Step::Conditions {
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            description: "Restore network",
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            config: NetemConfig::new()
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                .latency(Duration::from_millis(20))
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                .link(Bitrate::mbps(3), DataSize::kbytes(100))
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                .seed(42),
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        },
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        Step::Run {
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            description: "Allow full recovery via AIMD + probes",
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            duration: Duration::from_secs(15),
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        },
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        Step::Check {
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            description: "Estimate recovers to original level",
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            at_least: Bitrate::mbps(2),
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        },
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    ];
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    let (mut l, mut r) = connect_with_bwe(Bitrate::mbps(2), Bitrate::mbps(5));
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    let mut ctx = BweTestContext::new(&mut l, &mut r);
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    ctx.run_plan(&mut l, &mut r, &plan)?;
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    Ok(())
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}