use std::collections::HashMap;
use std::process::Command;

pub struct PowerPlan {
    power_plan_map: HashMap<i32, String>,
}

impl PowerPlan {
    pub fn new() -> Self {
        let mut power_plan_map = HashMap::new();
        power_plan_map.insert(PowerPlanMode::PowerSaving as i32, "a1841308-3541-4fab-bc81-f71556f20b4a".to_string());
        power_plan_map.insert(PowerPlanMode::Balanced as i32, "381b4222-f694-41f0-9685-ff5bb260df2e".to_string());
        power_plan_map.insert(PowerPlanMode::HighPerformance as i32, "8c5e7fda-e8bf-4a96-9a85-a6e23a8c635c".to_string());
        power_plan_map.insert(PowerPlanMode::Extreme as i32, "e9a42b02-d5df-448d-aa00-03f14749eb61".to_string());

        PowerPlan { power_plan_map }
    }

    pub fn set(&self, mode: i32) -> Result<(), String> {
        let guid = self.power_plan_map.get(&mode).ok_or("Invalid power plan number (expect from 1 to 4)")?;

        let output = Command::new("powercfg")
            .arg("/S")
            .arg(guid)
            .output()
            .map_err(|e| format!("Failed to execute powercfg command: {}", e))?;

        if !output.status.success() {
            return Err(format!("Powercfg command failed: {}", String::from_utf8_lossy(&output.stderr)));
        }

        Ok(())
    }

    pub fn get(&self) -> Result<i32, String> {
        let output = Command::new("powercfg")
            .arg("/L")
            .output()
            .map_err(|e| format!("Failed to execute powercfg command: {}", e))?;

        let output_str = String::from_utf8_lossy(&output.stdout);
        let re = regex::Regex::new(r"GUID:\s+(\S+)\s+\(\S+\)\s+\*")
            .map_err(|e| format!("Failed to compile regex: {}", e))?;

        let res = re.captures(&output_str).ok_or("No matching power plan found")?;
        let guid = res.get(1).ok_or("No GUID found in power plan output")?.as_str();

        for (k, v) in &self.power_plan_map {
            if guid == v {
                return Ok(*k);
            }
        }

        Err("No matching power plan found in map".to_string())
    }
}

#[allow(dead_code)]
pub enum PowerPlanMode {
    Other = 0,
    PowerSaving = 1,
    Balanced = 2,
    HighPerformance = 3,
    Extreme = 4,
}

pub fn get_powerplan() -> Result<String, String> {
    let power_plan = PowerPlan::new();
    let mode = power_plan.get()?;
    Ok(mode.to_string())
}

pub fn set_powerplan(plan: &str) -> Result<String, String> {
    let mode: i32 = plan.parse().map_err(|_| "Invalid power plan number")?;
    let power_plan = PowerPlan::new();
    power_plan.set(mode)?;
    Ok("Power plan set successfully".to_string())
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_set_power_plan() {
        let power_plan = PowerPlan::new();
        // 测试设置节能模式
        let result = power_plan.set(PowerPlanMode::PowerSaving as i32);
        assert!(result.is_ok(), "Failed to set power saving plan");

        // 测试设置无效模式
        let result = power_plan.set(99);
        assert!(result.is_err(), "Setting invalid power plan should fail");
    }

    #[test]
    fn test_get_power_plan() {
        let power_plan = PowerPlan::new();
        // 测试获取当前电源计划
        let result = power_plan.get();
        assert!(result.is_ok(), "Failed to get current power plan");

        // 验证返回的模式是否在有效范围内
        let mode = result.unwrap();
        assert!((1..=4).contains(&mode), "Invalid power plan mode returned");
        println!("Mode: {} - {}", mode, PowerPlan::new().power_plan_map[&mode]);

    }
}