shiritori/src/database.rs

use crate::Word;

use derive_more::From;
use std::path::PathBuf;
use rusqlite::{Connection, Result, params};

pub struct Database {
    conn: Connection,
}

#[derive(From, Debug)]
pub enum DatabaseCreationError {
    RusqliteError(rusqlite::Error),
    IoError(std::io::Error),
}

impl Database {
    pub fn new(
        testing: bool,
    ) -> Result<Self, DatabaseCreationError> {
        let conn = if testing {
            Connection::open_in_memory()
        } else {
            let path = PathBuf::from("shiritori.db");
            //fs::create_dir_all(path.parent().unwrap())?;
            Connection::open(path)
        }?;
        conn.execute(
            "CREATE TABLE IF NOT EXISTS word (
                id        INTEGER PRIMARY KEY,
                word      TEXT, reading   TEXT,
                timestamp DATETIME DEFAULT CURRENT_TIMESTAMP,
            )",
            params![],
        )?;
        Ok(Self { conn })
    }

    pub fn load_words_before(&self, before_id: i64) -> Result<Vec<Word>> {
        self.conn
            .prepare("SELECT id, word, reading, timestamp FROM word WHERE id < ? DESC LIMIT 10")?
            .query_map(params![before_id], |row| {
                Ok(Word {
                    id: row.get(0)?,
                    word: row.get(1)?,
                    reading: row.get(2)?,
                    timestamp: row.get(3)?,
                })
            })?
            .collect::<Result<Vec<Word>>>()
    }
}