//! Chrome Power API Implementation
//!
//! Provides functionality to override system power management features.
//!
//! ## Features
//! - Request system to stay awake
//! - Release wake lock

use serde::{Deserialize, Serialize};
use serde_json::{json, Value};
use std::collections::HashSet;
use std::sync::{Arc, RwLock};

use crate::error::{ExtensionError, ExtensionResult};

/// Power level
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq, Hash)]
#[serde(rename_all = "snake_case")]
pub enum Level {
    /// Prevent system from sleeping
    System,
    /// Prevent display from turning off or dimming
    Display,
}

/// Power API handler
pub struct PowerApi {
    /// Active power requests per extension
    requests: Arc<RwLock<HashSet<(String, Level)>>>,
}

impl Default for PowerApi {
    fn default() -> Self {
        Self::new()
    }
}

impl PowerApi {
    /// Create a new PowerApi instance
    pub fn new() -> Self {
        Self {
            requests: Arc::new(RwLock::new(HashSet::new())),
        }
    }

    /// Request power level
    pub fn request_keep_awake(&self, extension_id: &str, level: Level) -> ExtensionResult<Value> {
        let mut requests = self.requests.write().unwrap();
        requests.insert((extension_id.to_string(), level));

        // In a real implementation, this would call system APIs to prevent sleep
        // Windows: SetThreadExecutionState
        // macOS: IOPMAssertionCreateWithName
        // Linux: D-Bus inhibit

        Ok(json!(null))
    }

    /// Release power request
    pub fn release_keep_awake(&self, extension_id: &str) -> ExtensionResult<Value> {
        let mut requests = self.requests.write().unwrap();
        requests.retain(|(id, _)| id != extension_id);

        // In a real implementation, this would release the system wake lock

        Ok(json!(null))
    }

    /// Report activity (ChromeOS only)
    pub fn report_activity(&self) -> ExtensionResult<Value> {
        // This is a no-op on non-ChromeOS platforms
        Ok(json!(null))
    }

    /// Handle API call
    pub fn handle(
        &self,
        method: &str,
        params: Value,
        extension_id: &str,
    ) -> ExtensionResult<Value> {
        match method {
            "requestKeepAwake" => {
                let level_str = params
                    .get("level")
                    .and_then(|v| v.as_str())
                    .unwrap_or("system");
                let level = match level_str {
                    "display" => Level::Display,
                    _ => Level::System,
                };
                self.request_keep_awake(extension_id, level)
            }
            "releaseKeepAwake" => self.release_keep_awake(extension_id),
            "reportActivity" => self.report_activity(),
            _ => Err(ExtensionError::UnknownMethod(method.to_string())),
        }
    }
}

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

    #[test]
    fn test_request_keep_awake() {
        let api = PowerApi::new();
        let result = api.request_keep_awake("test-ext", Level::System);
        assert!(result.is_ok());
    }

    #[test]
    fn test_release_keep_awake() {
        let api = PowerApi::new();
        api.request_keep_awake("test-ext", Level::Display).unwrap();
        let result = api.release_keep_awake("test-ext");
        assert!(result.is_ok());
    }
}
