use log::{debug, info, warn};
use rocket::{
    get, post,
    request::FlashMessage,
    response::{Flash, Redirect},
};

use rocket_dyn_templates::Template;
use serde::Serialize;
use std::{
    io,
    process::{Command, Output},
};

use peach_lib::config_manager::load_peach_config;
use peach_lib::stats_client::{CpuStatPercentages, DiskUsage, LoadAverage, MemStat};
use peach_lib::{dyndns_client, network_client, oled_client, sbot_client, stats_client};

use crate::utils::build_json_response;
use crate::routes::authentication::Authenticated;
use rocket::serde::json::Value;

// HELPERS AND ROUTES FOR /device

/// System statistics data.
#[derive(Debug, Serialize)]
pub struct DeviceContext {
    pub back: Option<String>,
    pub cpu_stat_percent: Option<CpuStatPercentages>,
    pub disk_stats: Vec<DiskUsage>,
    pub flash_name: Option<String>,
    pub flash_msg: Option<String>,
    pub load_average: Option<LoadAverage>,
    pub mem_stats: Option<MemStat>,
    pub network_ping: String,
    pub oled_ping: String,
    pub stats_ping: String,
    pub dyndns_enabled: bool,
    pub dyndns_is_online: bool,
    pub config_is_valid: bool,
    pub sbot_is_online: bool,
    pub title: Option<String>,
    pub uptime: Option<i32>,
}

impl DeviceContext {
    pub fn build() -> DeviceContext {
        // convert result to Option<CpuStatPercentages>, discard any error
        let cpu_stat_percent = stats_client::cpu_stats_percent().ok();
        let load_average = stats_client::load_average().ok();
        let mem_stats = stats_client::mem_stats().ok();
        let network_ping = match network_client::ping() {
            Ok(_) => "ONLINE".to_string(),
            Err(_) => "OFFLINE".to_string(),
        };
        let oled_ping = match oled_client::ping() {
            Ok(_) => "ONLINE".to_string(),
            Err(_) => "OFFLINE".to_string(),
        };
        let stats_ping = match stats_client::ping() {
            Ok(_) => "ONLINE".to_string(),
            Err(_) => "OFFLINE".to_string(),
        };
        let uptime = match stats_client::uptime() {
            Ok(mins) => mins,
            Err(_) => "Unavailable".to_string(),
        };

        // serialize disk usage data into Vec<DiskUsage>
        let disk_usage_stats = match stats_client::disk_usage() {
            Ok(disks) => {
                let partitions: Vec<DiskUsage> = serde_json::from_str(disks.as_str())
                    .expect("Failed to deserialize disk_usage response");
                partitions
            }
            Err(_) => Vec::new(),
        };

        let mut disk_stats = Vec::new();
        // select only the partition we're interested in: /dev/mmcblk0p2 ("/")
        for disk in disk_usage_stats {
            if disk.mountpoint == "/" {
                disk_stats.push(disk);
            }
        }

        // parse the uptime string to a signed integer (for math)
        let uptime_parsed = uptime.parse::<i32>().ok();

        // dyndns_is_online & config_is_valid
        let dyndns_enabled: bool;
        let dyndns_is_online: bool;
        let config_is_valid: bool;
        let load_peach_config_result = load_peach_config();
        match load_peach_config_result {
            Ok(peach_config) => {
                dyndns_enabled = peach_config.dyn_enabled;
                config_is_valid = true;
                if dyndns_enabled {
                    let is_dyndns_online_result = dyndns_client::is_dns_updater_online();
                    match is_dyndns_online_result {
                        Ok(is_online) => {
                            dyndns_is_online = is_online;
                        }
                        Err(_err) => {
                            dyndns_is_online = false;
                        }
                    }
                } else {
                    dyndns_is_online = false;
                }
            }
            Err(_err) => {
                dyndns_enabled = false;
                dyndns_is_online = false;
                config_is_valid = false;
            }
        }

        // test if go-sbot is running
        let sbot_is_online: bool;
        let sbot_is_online_result = sbot_client::is_sbot_online();
        match sbot_is_online_result {
            Ok(val) => {
                sbot_is_online = val;
            }
            Err(_err) => {
                sbot_is_online = false;
            }
        }

        DeviceContext {
            back: None,
            cpu_stat_percent,
            disk_stats,
            flash_name: None,
            flash_msg: None,
            load_average,
            mem_stats,
            network_ping,
            oled_ping,
            stats_ping,
            dyndns_enabled,
            dyndns_is_online,
            config_is_valid,
            sbot_is_online,
            title: None,
            uptime: uptime_parsed,
        }
    }
}

#[get("/device")]
pub fn device_stats(flash: Option<FlashMessage>, auth: Authenticated) -> Template {
    // assign context through context_builder call
    let mut context = DeviceContext::build();
    context.back = Some("/".to_string());
    context.title = Some("Device Status".to_string());
    // check to see if there is a flash message to display
    if let Some(flash) = flash {
        // add flash message contents to the context object
        context.flash_name = Some(flash.kind().to_string());
        context.flash_msg = Some(flash.message().to_string());
    };
    // template_dir is set in Rocket.toml
    Template::render("device", &context)
}

// HELPERS AND ROUTES FOR /device/reboot

/// Executes a system command to reboot the device immediately.
pub fn reboot() -> io::Result<Output> {
    info!("Rebooting the device");
    // ideally, we'd like to reboot after 5 seconds to allow time for JSON
    // response but this is not possible with the `shutdown` command alone.
    // TODO: send "rebooting..." message to `peach-oled` for display
    Command::new("sudo")
        .arg("shutdown")
        .arg("-r")
        .arg("now")
        .output()
}

#[get("/device/reboot")]
pub fn reboot_cmd(auth: Authenticated) -> Flash<Redirect> {
    match reboot() {
        Ok(_) => Flash::success(Redirect::to("/shutdown"), "Rebooting the device"),
        Err(_) => Flash::error(Redirect::to("/shutdown"), "Failed to reboot the device"),
    }
}

/// JSON request handler for device reboot.
#[post("/api/v1/device/reboot")]
pub fn reboot_device(auth: Authenticated) -> Value {
    match reboot() {
        Ok(_) => {
            debug!("Going down for reboot...");
            let status = "success".to_string();
            let msg = "Going down for reboot.".to_string();
            build_json_response(status, None, Some(msg))
        }
        Err(_) => {
            warn!("Reboot failed");
            let status = "error".to_string();
            let msg = "Failed to reboot the device.".to_string();
            build_json_response(status, None, Some(msg))
        }
    }
}

// HELPERS AND ROUTES FOR /device/shutdown

/// Executes a system command to shutdown the device immediately.
pub fn shutdown() -> io::Result<Output> {
    info!("Shutting down the device");
    // ideally, we'd like to reboot after 5 seconds to allow time for JSON
    // response but this is not possible with the `shutdown` command alone.
    // TODO: send "shutting down..." message to `peach-oled` for display
    Command::new("sudo").arg("shutdown").arg("now").output()
}

#[get("/device/shutdown")]
pub fn shutdown_cmd(auth: Authenticated) -> Flash<Redirect> {
    match shutdown() {
        Ok(_) => Flash::success(Redirect::to("/shutdown"), "Shutting down the device"),
        Err(_) => Flash::error(Redirect::to("/shutdown"), "Failed to shutdown the device"),
    }
}

// shutdown the device
#[post("/api/v1/device/shutdown")]
pub fn shutdown_device(auth: Authenticated) -> Value {
    match shutdown() {
        Ok(_) => {
            debug!("Going down for shutdown...");
            let status = "success".to_string();
            let msg = "Going down for shutdown.".to_string();
            build_json_response(status, None, Some(msg))
        }
        Err(_) => {
            warn!("Shutdown failed");
            let status = "error".to_string();
            let msg = "Failed to shutdown the device.".to_string();
            build_json_response(status, None, Some(msg))
        }
    }
}

// HELPERS AND ROUTES FOR /shutdown

#[derive(Debug, Serialize)]
pub struct ShutdownContext {
    pub back: Option<String>,
    pub flash_name: Option<String>,
    pub flash_msg: Option<String>,
    pub title: Option<String>,
}

impl ShutdownContext {
    pub fn build() -> ShutdownContext {
        ShutdownContext {
            back: None,
            flash_name: None,
            flash_msg: None,
            title: None,
        }
    }
}

#[get("/shutdown")]
pub fn shutdown_menu(flash: Option<FlashMessage>, auth: Authenticated) -> Template {
    let mut context = ShutdownContext::build();
    context.back = Some("/".to_string());
    context.title = Some("Shutdown Device".to_string());
    // check to see if there is a flash message to display
    if let Some(flash) = flash {
        // add flash message contents to the context object
        context.flash_name = Some(flash.kind().to_string());
        context.flash_msg = Some(flash.message().to_string());
    };
    Template::render("shutdown", &context)
}