use super::{Data, ErrorCode, MTTError, Table};
use std::collections::HashMap;

#[derive(Clone, Debug)]
pub struct Database {
    data: HashMap<String, Data<Table>>,
}

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

    pub fn add<S>(&mut self, name: S) -> Result<(), MTTError>
    where
        S: Into<String>,
    {
        let db_name = name.into();
        match self.get(&db_name) {
            Some(_) => Err(MTTError::from_code(ErrorCode::DuplicateTable(db_name))),
            None => {
                self.data.insert(db_name, Data::from_data(Table::new()));
                Ok(())
            }
        }
    }

    pub fn add_by_id<S, D>(&mut self, name: S, id: D) -> Result<(), MTTError>
    where
        S: Into<String>,
        D: Into<String>,
    {
        let db_name = name.into();
        match self.get(&db_name) {
            Some(_) => Err(MTTError::from_code(ErrorCode::DuplicateTable(db_name))),
            None => {
                self.data.insert(db_name, Data::from_id(id.into()));
                Ok(())
            }
        }
    }

    pub fn get(&self, name: &str) -> Option<&Data<Table>> {
        self.data.get(name)
    }

    pub fn list(&self) -> Vec<String> {
        let mut names = Vec::new();
        for name in self.data.keys() {
            names.push(name.to_string());
        }
        names.sort();
        names
    }
}

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

    #[test]
    fn create_new() {
        let db = Database::new();
        let expected: Vec<String> = Vec::new();
        assert_eq!(db.list(), expected);
    }

    #[test]
    fn add_db_by_str() {
        let mut db = Database::new();
        let name = "Melvin";
        db.add(name).unwrap();
        let output = db.get(name);
        assert!(output.is_some(), "Get returned none.");
    }

    #[test]
    fn add_db_by_string() {
        let mut db = Database::new();
        let name = "Marvin";
        db.add(name.to_string()).unwrap();
        let output = db.get(name);
        assert!(output.is_some(), "Get returned none.");
    }

    #[test]
    fn fail_on_duplicates() -> Result<(), MTTError> {
        let mut db = Database::new();
        let name = "Mickie";
        db.add(name).unwrap();
        match db.add(name) {
            Ok(_) => Err(MTTError::new("duplicates should error")),
            Err(err) => match err.code {
                ErrorCode::DuplicateTable(db_name) => {
                    assert_eq!(db_name, name);
                    Ok(())
                }
                _ => Err(MTTError::new(format!("{:?} is not DuplicateTable", err))),
            },
        }
    }

    #[test]
    fn add_using_cache_id() {
        let mut db = Database::new();
        let name = "fred";
        let id = "12345";
        db.add_by_id(name, id).unwrap();
        let output = db.get(name).unwrap();
        assert!(output.data.is_none(), "there should be no data");
        assert_eq!(output.id, Some(id.to_string()));
    }

    #[test]
    fn add_by_cache_id_name_string() {
        let mut db = Database::new();
        let name = "barney";
        let id = "67890";
        db.add_by_id(name.to_string(), id).unwrap();
        let output = db.get(name).unwrap();
        assert!(output.data.is_none(), "there should be no data");
        assert_eq!(output.id, Some(id.to_string()));
    }

    #[test]
    fn no_duplicate_databases_for_add_by_id() {
        let mut db = Database::new();
        let name = "betty";
        db.add_by_id(name, "fghij").unwrap();
        match db.add_by_id(name, "klmno") {
            Ok(_) => assert!(false, "Duplicates should error."),
            Err(err) => match err.code {
                ErrorCode::DuplicateTable(db_name) => assert_eq!(db_name, name),
                _ => assert!(false, "{:?} is not DuplicateTable", err),
            },
        }
    }

    #[test]
    fn add_by_cache_id_string() {
        let mut db = Database::new();
        let name = "wilma";
        let id = "abcdef";
        db.add_by_id(name, id.to_string()).unwrap();
        let output = db.get(name).unwrap();
        assert!(output.data.is_none(), "there should be no data");
        assert_eq!(output.id, Some(id.to_string()));
    }

    #[test]
    fn get_bad_database() -> Result<(), MTTError> {
        let db = Database::new();
        match db.get("missing") {
            Some(_) => Err(MTTError::new("Should have returned None.")),
            None => Ok(()),
        }
    }

    #[test]
    fn get_list() {
        let mut db = Database::new();
        let mut ids = ["one", "two", "three", "four", "five"];
        for name in ids {
            db.add(name.to_string()).unwrap();
        }
        ids.sort();
        assert_eq!(db.list(), ids);
    }
}