use std::{io, path, process::exit};

use io::Write;

use clap::Parser;
use cli::CliArgs;
use rusqlite::{Connection, params_from_iter};

const DB_PATH: &str = ".tags";

mod cli;

fn main() {
	let args = CliArgs::parse();

	match args.commands {
		cli::Commands::Init => {
			if !has_database() {
				let conn = Connection::open(DB_PATH).unwrap();
				init_db(&conn);
			} else {
				panic!("Database is already initialized in this folder");
			}
			exit(0);
		}
		cli::Commands::Tags(args) => {
			let conn = Connection::open(DB_PATH).unwrap();

			if args.list {
				let mut w = io::stdout();
				let tags = list_tags(&conn);
				for tag in tags {
					writeln!(&mut w, "{}", tag).unwrap();
				}
				w.flush().unwrap();
				return;
			}

			match args.commands {
				Some(cli::TagsCommands::Add { add }) => add_tags(&conn, add),
				Some(cli::TagsCommands::Remove { remove }) => remove_tags(&conn, remove),
				_ => (),
			};
		}
	}
}

fn list_tags(conn: &Connection) -> Vec<String> {
	let mut stmt = conn.prepare("SELECT name FROM tag").unwrap();
	let result = stmt.query_map([], |row| row.get(0)).unwrap();

	let mut tags = Vec::new();
	for name in result {
		tags.push(name.unwrap());
	}

	tags
}

fn remove_tags(conn: &Connection, tags: Vec<String>) {
	let mut query = r#"DELETE FROM tag WHERE name IN ("#.to_string();

	for (i, _tag) in tags.iter().enumerate() {
		query.push('?');
		if i < tags.len() - 1 {
			query.push(',');
		}
	}

	query.push(')');

	conn.execute(&query, params_from_iter(tags)).unwrap();
}

fn add_tags(conn: &Connection, tags: Vec<String>) {
	let mut query = r#"INSERT INTO tag(name) VALUES"#.to_string();

	for (i, _tag) in tags.iter().enumerate() {
		query.push_str("(?)");
		if i < tags.len() - 1 {
			query.push(',');
		}
	}

	conn.execute(&query, params_from_iter(tags)).unwrap();
}

fn init_db(conn: &Connection) {
	conn.execute(
		r#"CREATE TABLE IF NOT EXISTS tag(
			id INTEGER PRIMARY KEY AUTOINCREMENT, 
			name VARCHAR(255) NOT NULL UNIQUE
		);"#,
		(),
	)
	.unwrap();

	conn.execute(
		r#"CREATE TABLE IF NOT EXISTS file(
			id INT NOT NULL PRIMARY KEY, 
			path VARCHAR(255) NOT NULL UNIQUE
		);"#,
		(),
	)
	.unwrap();

	conn.execute(
		r#"CREATE TABLE IF NOT EXISTS file_tag(
			tag_id INT REFERENCES tag(id), 
			file_id INT REFERENCES file(id)
		);"#,
		(),
	)
	.unwrap();
}

pub fn has_database() -> bool {
	path::Path::new(DB_PATH).exists()
}