use crate::logger::LOGFILE_PATH;
use num_enum::TryFromPrimitive;
use ops_sat_rs::config::{
    action_err::INVALID_ACTION_ID, HOME_FOLDER_EXPERIMENT, HOME_PATH, STOP_FILE_NAME,
    TO_GROUND_FOLDER_EXPERIMENT,
};
use satrs::action::ActionRequestVariant;
use satrs::{
    action::ActionRequest,
    params::Params,
    pus::action::{ActionReplyPus, ActionReplyVariant},
    request::{GenericMessage, MessageMetadata},
    res_code::ResultU16,
};
use serde::{Deserialize, Serialize};
use std::{
    env::temp_dir,
    path::{Path, PathBuf},
    process::Command,
    sync::{atomic::AtomicBool, mpsc, Arc},
};

use ops_sat_rs::config::ctrl_err::{
    SHELL_CMD_EXECUTION_FAILURE, SHELL_CMD_INVALID_FORMAT, SHELL_CMD_IO_ERROR,
};

use crate::requests::CompositeRequest;

#[derive(Serialize, Deserialize, Debug)]
pub struct ShellCmd<'a> {
    cmd: &'a str,
    args: Vec<&'a str>,
}

#[derive(Debug, Clone, Copy, TryFromPrimitive)]
#[repr(u32)]
pub enum ActionId {
    StopExperiment = 1,
    DownlinkLogfile = 2,
    DownlinkImages = 3,
    ExecuteShellCommandBlocking = 4,
}

pub struct ExperimentController {
    pub composite_request_rx: mpsc::Receiver<GenericMessage<CompositeRequest>>,
    pub action_reply_tx: mpsc::Sender<GenericMessage<ActionReplyPus>>,
    pub stop_signal: Arc<AtomicBool>,
    home_path_stop_file: PathBuf,
    tmp_path_stop_file: PathBuf,
}

impl ExperimentController {
    pub fn new(
        composite_request_rx: mpsc::Receiver<GenericMessage<CompositeRequest>>,
        action_reply_tx: mpsc::Sender<GenericMessage<ActionReplyPus>>,
        stop_signal: Arc<AtomicBool>,
    ) -> Self {
        let mut home_path_stop_file = PathBuf::new();
        home_path_stop_file.push(HOME_PATH.as_path());
        home_path_stop_file.push(STOP_FILE_NAME);
        let mut tmp_path_stop_file = temp_dir();
        tmp_path_stop_file.push(STOP_FILE_NAME);
        Self {
            composite_request_rx,
            action_reply_tx,
            stop_signal,
            home_path_stop_file,
            tmp_path_stop_file,
        }
    }
}

impl ExperimentController {
    pub fn perform_operation(&mut self) {
        match self.composite_request_rx.try_recv() {
            Ok(msg) => match msg.message {
                CompositeRequest::Hk(_) => {
                    log::warn!("hk request handling unimplemented")
                }
                CompositeRequest::Action(action_req) => {
                    self.handle_action_request(msg.requestor_info, action_req);
                }
            },
            Err(e) => {
                if e != mpsc::TryRecvError::Empty {
                    log::error!("composite request rx error: {:?}", e);
                }
            }
        }
        self.check_stop_file();
    }

    pub fn handle_action_request(&mut self, requestor: MessageMetadata, action_req: ActionRequest) {
        let send_completion_failure = |error_code: ResultU16, params: Option<Params>| {
            let result = self.action_reply_tx.send(GenericMessage::new_action_reply(
                requestor,
                action_req.action_id,
                ActionReplyVariant::CompletionFailed { error_code, params },
            ));
            if result.is_err() {
                log::error!("sending action reply failed");
            }
        };
        let action_id = ActionId::try_from(action_req.action_id);
        if action_id.is_err() {
            send_completion_failure(INVALID_ACTION_ID, None);
            return;
        }
        match action_id.unwrap() {
            ActionId::StopExperiment => {
                self.stop_signal
                    .store(true, std::sync::atomic::Ordering::Relaxed);
                self.send_completion_success(&requestor, &action_req);
            }
            ActionId::ExecuteShellCommandBlocking => {
                self.handle_shell_command_execution(&requestor, &action_req);
            }
            ActionId::DownlinkLogfile => self.handle_downlink_logfile(&requestor, &action_req),
            // downlink images, default will be the last image, otherwise specified counting down (2 = second to last image, etc.)
            ActionId::DownlinkImages => {
                log::info!("Copying images into low priority downlink folder");
                if let Ok(image_path) = match action_req.variant {
                    ActionRequestVariant::VecData(data) => {
                        let index = data[0];
                        get_latest_image(index as usize)
                    }
                    _ => get_latest_image(0),
                } {
                    if let Ok(image_path) = <PathBuf as Clone>::clone(&image_path)
                        .into_os_string()
                        .into_string()
                    {
                        if std::fs::copy(image_path, TO_GROUND_FOLDER_EXPERIMENT).is_err() {
                            log::error!("Copying logfile into downlink path failed")
                        }
                    }
                }
            }
        }
    }

    pub fn handle_downlink_logfile(&self, requestor: &MessageMetadata, action_req: &ActionRequest) {
        log::info!("copying logfile into downlink folder");
        if let Some(logfile_path) = LOGFILE_PATH.get() {
            if let Ok(logfile_path) = <PathBuf as Clone>::clone(logfile_path)
                .into_os_string()
                .into_string()
            {
                if std::fs::copy(logfile_path.as_str(), TO_GROUND_FOLDER_EXPERIMENT).is_err() {
                    log::warn!("copying logfile into downlink path failed")
                }
                self.send_completion_success(requestor, action_req)
            }
        } else {
            log::warn!("downlink path emtpy")
        }
    }

    pub fn send_completion_success(&self, requestor: &MessageMetadata, action_req: &ActionRequest) {
        let result = self.action_reply_tx.send(GenericMessage::new_action_reply(
            *requestor,
            action_req.action_id,
            ActionReplyVariant::Completed,
        ));
        if result.is_err() {
            log::error!("sending action reply failed");
        }
    }

    pub fn send_completion_failure(
        &self,
        requestor: &MessageMetadata,
        action_req: &ActionRequest,
        error_code: ResultU16,
        params: Option<Params>,
    ) {
        let result = self.action_reply_tx.send(GenericMessage::new_action_reply(
            *requestor,
            action_req.action_id,
            ActionReplyVariant::CompletionFailed { error_code, params },
        ));
        if result.is_err() {
            log::error!("sending action reply failed");
        }
    }

    pub fn handle_shell_command_execution(
        &self,
        requestor: &MessageMetadata,
        action_req: &ActionRequest,
    ) {
        if let ActionRequestVariant::VecData(data) = &action_req.variant {
            let shell_cmd_result: serde_json::Result<ShellCmd> = serde_json::from_slice(data);
            match shell_cmd_result {
                Ok(shell_cmd) => {
                    log::info!("executing shell cmd {:?}", shell_cmd);
                    match Command::new(shell_cmd.cmd).args(shell_cmd.args).status() {
                        Ok(status) => {
                            if status.success() {
                                self.send_completion_success(requestor, action_req);
                            } else {
                                log::warn!("execution of command failed: {}", status);
                                self.send_completion_failure(
                                    requestor,
                                    action_req,
                                    SHELL_CMD_EXECUTION_FAILURE,
                                    Some(status.to_string().into()),
                                );
                            }
                        }
                        Err(e) => {
                            log::warn!("execution of command failed with IO error: {}", e);
                            self.send_completion_failure(
                                requestor,
                                action_req,
                                SHELL_CMD_IO_ERROR,
                                Some(e.to_string().into()),
                            );
                        }
                    }
                }
                Err(e) => {
                    log::warn!("failed to deserialize shell command: {}", e);
                    let result = self.action_reply_tx.send(GenericMessage::new_action_reply(
                        *requestor,
                        action_req.action_id,
                        ActionReplyVariant::Completed,
                    ));
                    if result.is_err() {
                        log::error!("Sending action reply failed");
                    }
                }
            }
        } else {
            log::warn!("no shell command was supplied for shell command action command");
            self.send_completion_failure(requestor, action_req, SHELL_CMD_INVALID_FORMAT, None);
        }
    }

    pub fn check_stop_file(&self) {
        let check_at_path = |path: &Path| {
            if path.exists() {
                log::warn!(
                    "Detected stop file name at {:?}. Initiating experiment shutdown",
                    path
                );
                // By default, clear the stop file.
                let result = std::fs::remove_file(path);
                if result.is_err() {
                    log::error!(
                        "failed to remove stop file at {:?}: {}",
                        path,
                        result.unwrap_err()
                    );
                }
                self.stop_signal
                    .store(true, std::sync::atomic::Ordering::Relaxed);
            }
        };
        check_at_path(self.tmp_path_stop_file.as_path());
        check_at_path(self.home_path_stop_file.as_path());
    }
}

// TODO no idea if this works in any way shape or form
pub fn get_latest_image(index: usize) -> Result<PathBuf, std::io::Error> {
    // Get the most recently modified file
    let mut png_files = std::fs::read_dir(HOME_FOLDER_EXPERIMENT)?
        .flatten()
        .filter(|f| match f.metadata() {
            Ok(metadata) => metadata.is_file(),
            Err(_) => false,
        })
        .filter(|f| match f.file_name().into_string() {
            Ok(name) => name.ends_with(".png"),
            Err(_) => false,
        })
        .collect::<Vec<std::fs::DirEntry>>();
    png_files.sort_by_key(|x| match x.metadata() {
        Ok(metadata) => {
            if let Ok(time) = metadata.modified() {
                time
            } else {
                std::time::SystemTime::UNIX_EPOCH
            }
        }
        Err(_) => std::time::SystemTime::UNIX_EPOCH,
    });

    png_files.reverse();
    if let Some(png) = png_files.into_iter().nth(index) {
        return Ok(png.path());
    }
    Err(std::io::Error::other("No latest image found"))
}
#[cfg(test)]
mod tests {
    use std::sync::{mpsc, Arc};

    use tempfile::NamedTempFile;

    use super::*;

    fn init() {
        env_logger::builder().is_test(true).init();
    }

    #[test]
    fn test_shell_cmd_exection() {
        init();
        let (composite_req_tx, composite_req_rx) = mpsc::channel();
        let (action_reply_tx, action_reply_rx) = mpsc::channel();
        let stop_signal = Arc::default();
        let mut exp_ctrl =
            ExperimentController::new(composite_req_rx, action_reply_tx, stop_signal);
        let named_temp_file = NamedTempFile::new().expect("creating temp file failed");
        let args = vec![named_temp_file
            .path()
            .to_str()
            .expect("converting path to str failed")];

        let cmd = ShellCmd { cmd: "rm", args };
        let cmd_serialized = serde_json::to_string(&cmd).expect("serialization failed");
        let action_req = satrs::action::ActionRequest {
            action_id: ActionId::ExecuteShellCommandBlocking as u32,
            variant: satrs::action::ActionRequestVariant::VecData(cmd_serialized.into_bytes()),
        };
        composite_req_tx
            .send(GenericMessage::new(
                MessageMetadata::new(1, 2),
                CompositeRequest::Action(action_req),
            ))
            .expect("sending action request failed");
        exp_ctrl.perform_operation();
        assert!(!named_temp_file.path().exists());
        let action_reply = action_reply_rx
            .try_recv()
            .expect("receiving action reply failed");
        assert_eq!(
            action_reply.message.action_id,
            ActionId::ExecuteShellCommandBlocking as u32
        );
        match action_reply.message.variant {
            ActionReplyVariant::Completed => (),
            _ => {
                panic!(
                    "unexecpted action reply variant {:?}",
                    action_reply.message.variant
                )
            }
        }
    }
}