use super::Config;
use super::GenericError;
use chrono::format::ParseError;
use chrono::NaiveDateTime;
use minreq::Response;
use serde::Deserialize;
use std::fmt::{Display, Formatter};
use std::sync::mpsc;
use std::sync::mpsc::Receiver;
use std::thread;
use std::time::{Duration, Instant};

pub trait Timestamped {
    fn timestamp(&self) -> Option<String>;
}

#[derive(Deserialize, Debug)]
pub struct ErrorModel {
    #[serde(rename(deserialize = "Message"))]
    pub message: Option<String>,
}

#[derive(Deserialize, Debug, Clone)]
pub struct TagModel {
    pub id: Option<String>,
    pub imei: Option<String>,
    #[serde(rename(deserialize = "batteryValue"))]
    pub battery_value: Option<i32>,
    #[serde(rename(deserialize = "btId"))]
    pub bt_id: Option<String>,
    #[serde(rename(deserialize = "nfcId"))]
    pub nfc_id: Option<String>,
}

impl TagModel {
    pub fn get_nick(&self, config: &Config) -> Option<String> {
        if let Some(id) = &self.id {
            if let Some(n) = config.nicknames.get(id) {
                Some(n.clone())
            } else {
                None
            }
        } else {
            None
        }
    }

    pub fn get_id(&self) -> Result<String, GenericError> {
        match &self.id {
            Some(id) => Ok(id.to_string()),
            None => Err(GenericError::MessagedError(
                "Could not find device id. Error probably on Yetzon server side.".to_owned(),
                None,
            )),
        }
    }
}

impl Display for TagModel {
    fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), std::fmt::Error> {
        let mut text = String::new();
        text += &format!(
            "  id = {}",
            self.id.as_ref().unwrap_or(&"unknown".to_owned())
        );
        text += &format!(
            "\n  imei = {}",
            self.imei.as_ref().unwrap_or(&"unknown".to_owned())
        );
        text += &format!(
            "\n  battery value = {}%",
            &self
                .battery_value
                .map(|v| v.to_string())
                .unwrap_or("unknown".to_owned())
        );
        text += &format!(
            "\n  bluetooth id = {}",
            &self.bt_id.as_ref().unwrap_or(&"unknown".to_owned())
        );
        text += &format!(
            "\n  NFC id = {}",
            &self.nfc_id.as_ref().unwrap_or(&"unknown".to_owned())
        );
        write!(f, "{}", text)
    }
}

#[derive(Deserialize, Debug, Clone)]
pub struct StateModel {
    pub id: Option<String>,
    pub timestamp: Option<String>,
    #[serde(skip_deserializing)]
    pub state: Option<String>,
    #[serde(rename(deserialize = "realState"))]
    pub real_state: Option<String>,
}

impl Timestamped for StateModel {
    fn timestamp(&self) -> Option<String> {
        self.timestamp.clone()
    }
}

#[derive(Deserialize, Debug, Clone)]
#[serde(deny_unknown_fields)]
pub struct LocationModel {
    pub timestamp: Option<String>,
    #[serde(rename(deserialize = "type"))]
    pub loc_type: Option<String>,
    #[serde(rename(deserialize = "coordinateLat"))]
    pub lat: Option<f64>,
    #[serde(rename(deserialize = "coordinateLng"))]
    pub lon: Option<f64>,
    pub accuracy: Option<f32>,
}

impl Timestamped for LocationModel {
    fn timestamp(&self) -> Option<String> {
        self.timestamp.clone()
    }
}

pub struct API {
    pub config: Config,
    location_req_que: Vec<String>,
}

impl API {
    pub fn new(config: Config) -> API {
        API {
            config: config,
            location_req_que: Vec::new(),
        }
    }

    pub fn get_tags(&mut self) -> Result<Vec<TagModel>, GenericError> {
        let response = self.request(self.config.tags_url.clone())?;
        let tags = response.json();
        if let Err(_) = tags {
            let err: ErrorModel = response.json()?;
            Err(GenericError::from(err))
        } else {
            tags.map_err(GenericError::from)
        }
    }

    pub fn get_states(&mut self, tag_id: &String) -> Result<Vec<StateModel>, GenericError> {
        let response = self.request(str::replace(&self.config.states_url, "{tag}", &tag_id))?;
        Ok(response.json()?)
    }

    pub fn queue_location(&mut self, tag_id: &String, state_id: &String) {
        let url = str::replace(&self.config.locations_url, "{tag}", &tag_id);
        let url = str::replace(&url, "{state}", &state_id);
        self.location_req_que.push(url);
    }

    pub fn begin_location_fetch(
        &mut self,
    ) -> Receiver<Result<Result<Vec<LocationModel>, ErrorModel>, GenericError>> {
        let (sender, receiver) = mpsc::channel();
        let mut locations = self.location_req_que.clone();
        let config = self.config.clone();

        // sleep for a second to make sure no overlaps with previous requests.
        thread::sleep(Duration::from_millis(1000));

        thread::spawn(move || {
            let (i_sender, i_receiver) = mpsc::channel();

            let mut idx = 0;
            let mut awaiting = 0;

            let mut timer = 0;
            let mut last_time = Instant::now();
            let interval = 1_000_000_000 / config.throttle as u128;
            loop {
                let sender = sender.clone();
                let config = config.clone();
                let i_sender = i_sender.clone();

                let now = Instant::now();
                let delta = (now - last_time).as_nanos();
                if timer > 0 {
                    timer = timer - delta.min(timer);
                }
                last_time = now;

                if awaiting <= config.throttle && timer < (interval * (config.throttle as u128 - 2))
                {
                    if locations.len() > idx {
                        let location = locations[idx].clone();
                        awaiting += 1;
                        thread::spawn(move || {
                            let response = minreq::get(location.clone())
                                .with_header("content-type", "application/json")
                                .with_header("x-api-key", &config.api_key)
                                .send()
                                .and_then(|r| match r.json() {
                                    Ok(loc) => Ok(Ok(loc)),
                                    Err(_) => Ok(Err(r.json()?)),
                                })
                                .map_err(GenericError::from);
                            i_sender.send((location, response)).ok();
                        });
                        timer += interval;
                        idx += 1;
                    } else {
                        while awaiting > 0 {
                            if let Ok((loc, rec)) = i_receiver.try_recv() {
                                API::add_error_back(loc, &rec, &mut locations);
                                awaiting -= 1;
                                sender.send(rec).ok();
                            }
                        }
                        if locations.len() <= idx {
                            break;
                        }
                    }
                } else {
                    if let Ok((loc, rec)) = i_receiver.try_recv() {
                        API::add_error_back(loc, &rec, &mut locations);
                        awaiting -= 1;
                        sender.send(rec).ok();
                    }
                }
            }
        });
        self.location_req_que.clear();
        receiver
    }

    pub fn get_between<T: Timestamped + Clone>(
        list: &Vec<T>,
        from: Option<NaiveDateTime>,
        to: Option<NaiveDateTime>,
        inclusive_from: bool,
        config: &Config,
    ) -> Vec<(NaiveDateTime, T)> {
        let mut timestamped = Vec::new();
        for item in list {
            if let Some(res) = API::parse_timestamp(&item.timestamp(), config) {
                match res {
                    Ok(t) => {
                        if let Some(to) = to {
                            if t > to {
                                continue;
                            }
                        }
                        let mut too_old = false;
                        if let Some(from) = from {
                            if t < from {
                                too_old = true;
                            }
                        }
                        if too_old {
                            if inclusive_from {
                                timestamped.push((t.clone(), item.clone()));
                            }
                            break;
                        }
                        timestamped.push((t.clone(), item.clone()));
                    }
                    Err(e) => panic!(e),
                }
            } else {
                println!("Skipped item, did not have timestmap");
            }
        }
        timestamped
    }

    fn add_error_back(
        location: String,
        rec: &Result<Result<Vec<LocationModel>, ErrorModel>, GenericError>,
        locations: &mut Vec<String>,
    ) -> bool {
        if let Ok(inner) = rec {
            if let Err(_) = inner {
                locations.push(location);
                true
            } else {
                false
            }
        } else {
            false
        }
    }

    fn request(&mut self, url: String) -> Result<Response, GenericError> {
        let response = minreq::get(url)
            .with_header("content-type", "application/json")
            .with_header("x-api-key", &self.config.api_key)
            .send();
        response.map_err(GenericError::from)
    }

    fn parse_timestamp(
        timestamp: &Option<String>,
        config: &Config,
    ) -> Option<Result<NaiveDateTime, ParseError>> {
        if let Some(timestamp) = &timestamp {
            Some(NaiveDateTime::parse_from_str(
                &timestamp,
                &config.timestamp_format,
            ))
        } else {
            None
        }
    }
}