use crate::err::Error;
use rustyline::error::ReadlineError;
use rustyline::Editor;
use serde_json::Value;
use surrealdb::engines::any::connect;
use surrealdb::error::Api as ApiError;
use surrealdb::opt::auth::Root;
use surrealdb::sql;
use surrealdb::sql::statements::SetStatement;
use surrealdb::sql::Statement;
use surrealdb::Error as SurrealError;
use surrealdb::Response;

#[tokio::main]
pub async fn init(matches: &clap::ArgMatches) -> Result<(), Error> {
	// Set the default logging level
	crate::cli::log::init(0);
	// Parse all other cli arguments
	let username = matches.value_of("user").unwrap();
	let password = matches.value_of("pass").unwrap();
	let endpoint = matches.value_of("conn").unwrap();
	let mut ns = matches.value_of("ns").map(str::to_string);
	let mut db = matches.value_of("db").map(str::to_string);
	// If we should pretty-print responses
	let pretty = matches.is_present("pretty");
	// Connect to the database engine
	let client = connect(endpoint).await?;
	// Sign in to the server if the specified dabatabase engine supports it
	let root = Root {
		username,
		password,
	};
	if let Err(error) = client.signin(root).await {
		match error {
			// Authentication not supported by this engine, we can safely continue
			SurrealError::Api(ApiError::AuthNotSupported) => {}
			error => {
				return Err(error.into());
			}
		}
	}
	// Create a new terminal REPL
	let mut rl = Editor::<()>::new().unwrap();
	// Load the command-line history
	let _ = rl.load_history("history.txt");
	// Configure the prompt
	let mut prompt = "> ".to_owned();
	// Loop over each command-line input
	loop {
		// Use namespace / database if specified
		if let (Some(namespace), Some(database)) = (&ns, &db) {
			match client.use_ns(namespace).use_db(database).await {
				Ok(()) => {
					prompt = format!("{namespace}/{database}> ");
				}
				Err(error) => eprintln!("{error}"),
			}
		}
		// Prompt the user to input SQL
		let readline = rl.readline(&prompt);
		// Check the user input
		match readline {
			// The user typed a query
			Ok(line) => {
				// Ignore all empty lines
				if line.is_empty() {
					continue;
				}
				// Add the entry to the history
				rl.add_history_entry(line.as_str());
				// Complete the request
				match sql::parse(&line) {
					Ok(query) => {
						for statement in query.iter() {
							match statement {
								Statement::Use(stmt) => {
									if let Some(namespace) = &stmt.ns {
										ns = Some(namespace.clone());
									}
									if let Some(database) = &stmt.db {
										db = Some(database.clone());
									}
								}
								Statement::Set(SetStatement {
									name,
									what,
								}) => {
									if let Err(error) = client.set(name, what).await {
										eprintln!("{error}");
									}
								}
								_ => {}
							}
						}
						let res = client.query(query).await;
						// Get the request response
						match process(pretty, res) {
							Ok(v) => println!("{v}"),
							Err(e) => eprintln!("{e}"),
						}
					}
					Err(error) => eprintln!("{error}"),
				}
			}
			// The user types CTRL-C
			Err(ReadlineError::Interrupted) => {
				break;
			}
			// The user typed CTRL-D
			Err(ReadlineError::Eof) => {
				break;
			}
			// There was en error
			Err(err) => {
				eprintln!("Error: {err:?}");
				break;
			}
		}
	}
	// Save the inputs to the history
	let _ = rl.save_history("history.txt");
	// Everything OK
	Ok(())
}

fn process(pretty: bool, res: surrealdb::Result<Response>) -> Result<String, Error> {
	// Catch any errors
	let values: Vec<Value> = res?.take(0)?;
	let value = Value::Array(values);
	// Check if we should prettify
	match pretty {
		// Don't prettify the response
		false => Ok(value.to_string()),
		// Yes prettify the response
		true => {
			// Pretty the JSON response
			let res = serde_json::to_string_pretty(&value)?;
			// Everything processed OK
			Ok(res)
		}
	}
}