use anyhow::Result;
use std::fs;
use std::path::PathBuf;
use ember_tune_rs::sal::safety::{HardwareStateGuard, TdpLimitMicroWatts};
use crate::common::fakesys::FakeSysBuilder;

mod common;

#[test]
fn test_hardware_state_guard_panic_restoration() {
    let fake = FakeSysBuilder::new();
    let pl1_path = fake.base_path().join("sys/class/powercap/intel-rapl:0/constraint_0_power_limit_uw");
    
    fake.add_rapl("intel-rapl:0", "1000", "15000000"); // 15W original

    let target_files = vec![pl1_path.clone()];
    
    // Simulate a scope where the guard is active
    {
        let mut _guard = HardwareStateGuard::acquire(&target_files, &[]).expect("Failed to acquire guard");
        
        // Modify the file
        fs::write(&pl1_path, "25000000").expect("Failed to write new value");
        assert_eq!(fs::read_to_string(&pl1_path).unwrap().trim(), "25000000");
        
        // Guard is dropped here (simulating end of scope or panic)
    }

    // Verify restoration
    let restored = fs::read_to_string(&pl1_path).expect("Failed to read restored file");
    assert_eq!(restored.trim(), "15000000");
}

#[test]
fn test_tdp_limit_bounds_checking() {
    // 1. Valid value
    assert!(TdpLimitMicroWatts::new(15_000_000).is_ok());
    
    // 2. Too low (Dangerous 0W or below 5W)
    let low_res = TdpLimitMicroWatts::new(1_000_000);
    assert!(low_res.is_err());
    assert!(low_res.unwrap_err().to_string().contains("below safety floor"));

    // 3. Too high (> 80W)
    let high_res = TdpLimitMicroWatts::new(100_000_000);
    assert!(high_res.is_err());
    assert!(high_res.unwrap_err().to_string().contains("exceeds safety ceiling"));
}

#[test]
fn test_0w_tdp_regression_prevention() {
    // The prime directive is to never set 0W.
    // Ensure the new() constructor explicitly fails for 0.
    let zero_res = TdpLimitMicroWatts::new(0);
    assert!(zero_res.is_err());
}