use std::{fs, path::PathBuf};

fn platform_source(relative: &str) -> String {
    let root = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
    fs::read_to_string(root.join(relative)).expect("platform source must exist")
}

#[test]
fn former_motor_pins_are_inhibited_before_all_other_initialization() {
    let module = platform_source("src/f722/mod.rs");
    let interlock = module
        .find("motor_inhibit::inhibit_motor_pins")
        .expect("F722 initialization must claim the former motor pins first");
    let validation = module
        .find("config.validate()")
        .expect("F722 initialization must validate its board configuration");
    let board_initialization = module
        .find("board::initialize")
        .expect("F722 initialization must subsequently claim telemetry I/O");

    assert!(interlock < validation);
    assert!(validation < board_initialization);

    let interlock = platform_source("src/f722/motor_inhibit.rs");
    let reset = interlock
        .find("port.bsrr()")
        .expect("interlock must reset the former motor-pin output latches");
    let output_mode = interlock
        .find("port.moder()")
        .expect("interlock must configure the former motor pins as GPIO outputs");
    assert!(
        reset < output_mode,
        "output latches must be low before GPIO output mode is selected"
    );
    for pin in ["br0", "br1", "br4", "br5"] {
        assert!(interlock.contains(pin), "interlock must reset PB pin {pin}");
    }
    for pin in ["moder0", "moder1", "moder4", "moder5"] {
        assert!(
            interlock.contains(pin),
            "interlock must configure PB pin {pin}"
        );
    }
    for pin in ["ot0", "ot1", "ot4", "ot5"] {
        assert!(
            interlock.contains(pin),
            "interlock must set PB pin {pin} push-pull"
        );
    }
    for pin in ["ospeedr0", "ospeedr1", "ospeedr4", "ospeedr5"] {
        assert!(
            interlock.contains(pin),
            "interlock must set PB pin {pin} low speed"
        );
    }
}

#[test]
fn telemetry_platform_has_no_physical_actuator_peripheral_path() {
    let sources = [
        platform_source("src/lib.rs"),
        platform_source("src/f722/mod.rs"),
        platform_source("src/f722/board.rs"),
        platform_source("src/f722/firmware.rs"),
        platform_source("src/f722/interrupts.rs"),
    ]
    .join("\n");

    for forbidden in [
        "mod actuator",
        "MotorOutput",
        "MotorRoute",
        "MotorOutputs",
        "TIM3",
        "TIM5",
        "Dshot",
        "Pwm",
        "device.TIM3",
        "device.TIM5",
    ] {
        assert!(
            !sources.contains(forbidden),
            "telemetry platform must not expose actuator path {forbidden}"
        );
    }

    let manifest = platform_source("Cargo.toml");
    assert!(
        !manifest.contains("kaptan-actuator"),
        "telemetry platform must not link the physical actuator crate"
    );
}

#[test]
fn telemetry_has_no_inbound_command_authority() {
    let board = platform_source("src/f722/board.rs");
    let firmware = platform_source("src/f722/firmware.rs");

    assert!(
        !board.contains("MavlinkReceiver"),
        "telemetry must not retain an inbound MAVLink dispatch path"
    );
    assert!(
        !board.contains("ArmRequest"),
        "telemetry must not decode arm commands"
    );
    assert!(
        !board.contains("MAV_RESULT_ACCEPTED"),
        "telemetry must not accept an arm command"
    );
    assert!(
        !firmware.contains("shared = [mavlink, motors]"),
        "the MAVLink worker must not share a motor resource"
    );
    assert!(
        !firmware.contains("MAVLINK_EVENT_RECEIVED"),
        "telemetry must not schedule a worker from an inbound command"
    );
}