pub mod info;
mod sqlite;

pub mod server;

static NULL_PNG:&str = "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";

/// 根据参数从数据库中返回一条瓦片地图信息，如果没有则返回`NULL_PNG`
/// `tiles` mbtiles文件名
/// `z` 地图的zone
/// `x` 地图的x坐标
/// `y` 地图的y坐标
fn select_tile_data(tiles: &str, z: i32, x: i32, y: i32) -> Vec<u8> {
    let tile_data = match sqlite::select_tile_data(tiles, z, x, y) {
        Err(why) => {
            eprintln!("{}/{}/{}/{}: {}", tiles, z, x, y, why.to_string());
            base64::decode(NULL_PNG).unwrap()
        },
        Ok(tile_data) => tile_data
    };
    tile_data
}