use rusqlite::{params, Connection, Result};
// use std::collections::HashMap;

pub struct KeyValueStore {
    conn: Connection,
}

impl KeyValueStore {
    // Initialize the database and create the table if it doesn't exist
    pub fn new(db_path: &str) -> Result<Self> {
        let conn = Connection::open(db_path)?;
        conn.execute(
            "CREATE TABLE IF NOT EXISTS kv_store (
                  key TEXT PRIMARY KEY,
                  value TEXT NOT NULL
              )",
            [],
        )?;
        Ok(KeyValueStore { conn })
    }

    // Insert or update a key-value pair
    pub fn set(&self, key: &str, value: &str) -> Result<()> {
        self.conn.execute(
            "INSERT INTO kv_store (key, value) VALUES (?1, ?2)
             ON CONFLICT(key) DO UPDATE SET value = excluded.value",
            params![key, value],
        )?;
        Ok(())
    }

    pub fn default(&self, key: &str, value: &str) {
        self.conn.execute(
            "INSERT INTO kv_store (key, value) VALUES (?1, ?2)
             ON CONFLICT(key) DO NOTHING",
            params![key, value],
        ).ok();
    }

    // Retrieve a value by key
    pub fn get(&self, key: &str) -> Result<Option<String>> {
        let mut stmt = self.conn.prepare("SELECT value FROM kv_store WHERE key = ?1")?;
        let mut rows = stmt.query(params![key])?;

        if let Some(row) = rows.next()? {
            let value: String = row.get(0)?;
            Ok(Some(value))
        } else {
            Ok(None)
        }
    }

    // Delete a key-value pair
    pub fn delete(&self, key: &str) -> Result<()> {
        self.conn.execute("DELETE FROM kv_store WHERE key = ?1", params![key])?;
        Ok(())
    }
}


/*
fn main() -> Result<()> {
    let kv_store = KeyValueStore::new("kv_store.db")?;

    // Set some key-value pairs
    kv_store.set("last_week_pad", "pad_id_123")?;
    kv_store.set("email_id", "email_id_456")?;

    // Retrieve and print values
    if let Some(value) = kv_store.get("last_week_pad")? {
        println!("Last week's pad ID: {}", value);
    } else {
        println!("Key not found");
    }

    if let Some(value) = kv_store.get("email_id")? {
        println!("Email ID: {}", value);
    } else {
        println!("Key not found");
    }

    // Delete a key-value pair
    kv_store.delete("last_week_pad")?;

    Ok(())
}

*/