mod client;
mod data;
mod error;
mod message;
mod router;
mod session;

use client::{Client, ClientMsg};
use message::{Message, MsgData};
use router::Router;
use session::{Session, SessionData, SessionMsg};
use std::{
    collections::HashMap,
    ops::Deref,
    sync::mpsc::{channel, Sender},
};

struct Request;

#[derive(Clone)]
enum Field {
    Static(String),
}

impl From<String> for Field {
    fn from(value: String) -> Self {
        Field::Static(value)
    }
}

impl From<&str> for Field {
    fn from(value: &str) -> Self {
        Field::Static(value.into())
    }
}

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

    #[test]
    fn string_to_field() {
        let entries = ["test1".to_string(), "test2".to_string()];
        for data in entries {
            match data.clone().into() {
                Field::Static(result) => assert_eq!(result, data),
            }
        }
    }

    #[test]
    fn str_to_field() {
        let entries = ["test1", "test2"];
        for data in entries {
            match data.into() {
                Field::Static(result) => assert_eq!(result, data),
            }
        }
    }
}

struct Record {
    data: HashMap<String, Field>,
}

impl Record {
    fn new() -> Self {
        Self {
            data: HashMap::new(),
        }
    }

    fn add<S, F>(&mut self, name: S, data: F)
    where
        S: Into<String>,
        F: Into<Field>,
    {
        self.data.insert(name.into(), data.into());
    }
}

impl Deref for Record {
    type Target = HashMap<String, Field>;

    fn deref(&self) -> &Self::Target {
        &self.data
    }
}

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

    #[test]
    fn initialize() {
        let rec = Record::new();
        assert!(rec.is_empty());
    }

    #[test]
    fn bad_get_return() {
        let rec = Record::new();
        match rec.get("empty") {
            Some(_) => unreachable!("Should_have returned a None"),
            None => {}
        }
    }

    #[test]
    fn add_data() {
        let name = "name1x";
        let data = "data1";
        let mut rec = Record::new();
        rec.add(name, data);
        match rec.get(name) {
            None => unreachable!("Should return data"),
            Some(result) => match result {
                Field::Static(txt) => assert_eq!(txt, data),
            },
        }
    }

    #[test]
    fn add_data_strings() {
        let name = "field".to_string();
        let data = "info".to_string();
        let mut rec = Record::new();
        rec.add(name.clone(), data.clone());
        match rec.get(&name) {
            None => unreachable!("Should return data"),
            Some(result) => match result {
                Field::Static(txt) => assert_eq!(txt, &data),
            },
        }
    }
}

#[derive(Debug)]
enum ResponseError {
    ColumnNumberMisMatch,
    MissionColumn(String),
}

struct Response {
    data: HashMap<String, Vec<Field>>,
    counter: usize,
}

impl Response {
    fn new() -> Self {
        Self {
            data: HashMap::new(),
            counter: 0,
        }
    }

    fn add(&mut self, rec: Record) -> Result<(), ResponseError> {
        if self.data.is_empty() {
            for (key, value) in rec.iter() {
                let mut store = Vec::new();
                store.push(value.clone());
                self.data.insert(key.to_string(), store);
            }
        } else {
            if rec.len() != self.data.len() {
                return Err(ResponseError::ColumnNumberMisMatch);
            }
            for (key, value) in rec.iter() {
                match self.data.get_mut(key) {
                    Some(data) => data.push(value.clone()),
                    None => return Err(ResponseError::MissionColumn(key.to_string())),
                }
            }
        }
        Ok(())
    }
}

impl Iterator for Response {
    type Item = Record;

    fn next(&mut self) -> Option<Self::Item> {
        if self.data.is_empty() {
            return None;
        }
        let mut rec = Record::new();
        for (key, value) in self.data.iter() {
            if self.counter >= value.len() {
                return None;
            }
            rec.add(key, value[self.counter].clone());
        }
        self.counter += 1;
        Some(rec)
    }
}

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

    #[test]
    fn create_response() {
        let mut res = Response::new();
        assert!(res.data.is_empty());
        assert!(res.next().is_none());
    }

    #[test]
    fn add_records() {
        let mut res = Response::new();
        let columns = ["col1", "col2"];
        let count = 3;
        let field_cnt = &count * columns.len();
        let mut fields = 0..field_cnt;
        for _ in 0..count {
            let mut rec = Record::new();
            for col in columns {
                rec.add(col, fields.next().unwrap().to_string());
            }
            res.add(rec);
        }
        fields = 0..field_cnt;
        for _ in 0..count {
            match res.next() {
                Some(rec) => {
                    assert_eq!(rec.len(), columns.len());
                    for col in columns {
                        match rec.get(col).unwrap() {
                            Field::Static(txt) => {
                                assert_eq!(txt.clone(), fields.next().unwrap().to_string())
                            }
                        }
                    }
                }
                None => unreachable!("Should have returned data"),
            }
        }
        assert!(res.next().is_none(), "exceeded the correct of records");
    }

    #[test]
    fn number_of_columns_mismatch() {
        let mut res = Response::new();
        let mut rec1 = Record::new();
        let mut rec2 = Record::new();
        rec1.add("one", "one");
        rec2.add("one", "one");
        rec2.add("two", "two");
        res.add(rec1).unwrap();
        match res.add(rec2) {
            Ok(_) => unreachable!("Should not accept additional value"),
            Err(err) => match err {
                ResponseError::ColumnNumberMisMatch => {}
                _ => unreachable!("should havee been a mismatch error"),
            },
        }
    }

    #[test]
    fn missing_field_error() {
        let mut res = Response::new();
        let mut rec1 = Record::new();
        let mut rec2 = Record::new();
        rec1.add("one", "one");
        rec2.add("one", "one");
        rec2.add("two", "two");
        res.add(rec2).unwrap();
        match res.add(rec1) {
            Ok(_) => unreachable!("Should not accept additional value"),
            Err(err) => match err {
                ResponseError::ColumnNumberMisMatch => {}
                _ => unreachable!("should havee been a mismatch error"),
            },
        }
    }

    #[test]
    fn wrong_column_name() {
        let mut res = Response::new();
        let mut rec1 = Record::new();
        let mut rec2 = Record::new();
        rec1.add("one", "one");
        rec2.add("two", "two");
        res.add(rec1).unwrap();
        match res.add(rec2) {
            Ok(_) => unreachable!("Should not accept additional value"),
            Err(err) => match err {
                ResponseError::MissionColumn(txt) => assert_eq!(txt, "two"),
                _ => unreachable!("should have been missing cloumn"),
            },
        }
    }
}

/// Support functions for Messages.
pub trait Msg {
    fn to_msgdata(&self) -> MsgData;
}

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

    pub enum Tester {
        Test1,
        Test2,
    }

    impl Msg for Tester {
        fn to_msgdata(&self) -> MsgData {
            match self {
                Tester::Test1 => MsgData::Test1,
                Tester::Test2 => MsgData::Test2,
            }
        }
    }
}

/// Application client to MoreThanText
pub struct MoreThanText {
    session: Option<SessionData>,
    tx: Sender<Message>,
}

impl MoreThanText {
    /// Create a MoreThanText database.
    ///
    ///  Example:
    ///
    ///  ```
    ///  use morethantext::MoreThanText;
    ///
    ///  MoreThanText::new();
    ///  ```
    pub fn new() -> Self {
        let (tx, rx) = channel();
        let mut senders = Vec::new();
        senders.push(Client::start(tx.clone()));
        senders.push(Session::start(tx.clone()));
        Router::start(senders, rx);
        Self {
            session: None,
            tx: tx,
        }
    }

    /// Opens an existing or new session with the database.
    ///
    ///  If the string is None, incorrect, or expired,
    ///  a new session will be created.
    ///
    ///  Example:
    ///
    ///  ```
    ///  use morethantext::MoreThanText;
    ///
    ///  let mut mtt = MoreThanText::new();
    ///  mtt.open_session(None);
    ///  mtt.open_session(Some("7b1ff340-7dfa-4f29-b144-601384e54423".to_string()));
    ///  ```
    pub fn open_session(&mut self, id: Option<String>) {
        let (tx, rx) = channel();
        let req = ClientMsg::OpenSession(id, tx);
        let msg = Message::new(&req);
        self.tx.send(msg).unwrap();
        match rx.recv().unwrap().get_message() {
            MsgData::Session(data) => match data {
                SessionMsg::Opened(sess) => self.session = Some(sess.clone()),
                _ => {}
            },
            _ => {}
        };
    }

    /// Get the session id
    ///
    /// Example:
    ///
    /// ```
    ///  use morethantext::MoreThanText;
    ///
    ///  let mut mtt = MoreThanText::new();
    ///  let id = mtt.get_id();
    /// ```
    pub fn get_id(&self) -> String {
        match &self.session {
            Some(id) => id.to_string(),
            None => "".to_string(),
        }
    }
}

impl Clone for MoreThanText {
    fn clone(&self) -> Self {
        Self {
            session: None,
            tx: self.tx.clone(),
        }
    }
}

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

    #[test]
    fn default_values() {
        let mtt = MoreThanText::new();
        assert!(mtt.session.is_none());
    }

    #[test]
    fn new_session() {
        let mut mtt = MoreThanText::new();
        mtt.open_session(None);
        assert!(mtt.session.is_some());
    }

    #[test]
    fn session_ids_are_unique() {
        let mut mtt = MoreThanText::new();
        mtt.open_session(None);
        let id1 = mtt.get_id();
        mtt.open_session(None);
        assert_ne!(mtt.get_id(), id1);
    }

    #[test]
    fn cloned_clients_have_no_session() {
        let mut mtt = MoreThanText::new();
        mtt.open_session(None);
        let result = mtt.clone();
        assert!(result.session.is_none());
    }
}