#![warn(rust_2018_idioms)]
#![forbid(elided_lifetimes_in_paths, unsafe_code)]

mod time;

use crate::time::{parse_date, parse_time, Date, Time};
use camino::Utf8PathBuf as PathBuf;
use clap::Parser;
use serde::{Deserialize, Serialize};
use serde_with::{serde_as, DisplayFromStr};
use std::{
	fmt::Display,
	fs,
	io::{self, BufRead as _, Write}
};

#[derive(Debug, Parser)]
struct Args {
	#[clap(short = 'C', long, default_value = ".")]
	directory: PathBuf,

	#[clap(short = 'c', long, default_value = "23ws-malo")]
	course: String
}

#[derive(Deserialize, Serialize)]
struct Project {
	lecture: ProjectLecture,
	source: ProjectSource
}

#[serde_as]
#[derive(Deserialize, Serialize)]
struct ProjectLecture {
	course: String,
	#[serde_as(as = "DisplayFromStr")]
	date: Date
}

#[serde_as]
#[derive(Deserialize, Serialize)]
struct ProjectSource {
	files: Vec<String>,
	#[serde_as(as = "DisplayFromStr")]
	first_file_start: Time,
	#[serde_as(as = "DisplayFromStr")]
	last_file_end: Time
}

fn ask_time(question: impl Display) -> Time {
	let mut stdout = io::stdout().lock();
	let mut stdin = io::stdin().lock();

	writeln!(stdout, "{question}").unwrap();
	let mut line = String::new();
	loop {
		line.clear();
		write!(stdout, "> ").unwrap();
		stdout.flush().unwrap();
		stdin.read_line(&mut line).unwrap();
		let line = line.trim();
		match parse_time(line) {
			Ok(time) => return time,
			Err(err) => writeln!(stdout, "Invalid Input {line:?}: {err}").unwrap()
		}
	}
}

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

	// process arguments
	let directory = args.directory.canonicalize_utf8().unwrap();
	let course = args.course;

	// let's see if we need to initialise the project
	let project_path = directory.join("project.toml");
	let project = if project_path.exists() {
		toml::from_slice(&fs::read(&project_path).unwrap()).unwrap()
	} else {
		let dirname = directory.file_name().unwrap();
		let date =
			parse_date(dirname).expect("Directory name is not in the expected format");

		let mut files = Vec::new();
		for entry in directory.read_dir_utf8().unwrap() {
			let entry = entry.unwrap();
			let name = entry.file_name();
			let lower = name.to_ascii_lowercase();
			if (lower.ends_with(".mp4") || lower.ends_with(".mts"))
				&& entry.file_type().unwrap().is_file()
			{
				files.push(String::from(name));
			}
		}
		files.sort_unstable();
		assert!(!files.is_empty());
		println!("I found the following source files: {files:?}");

		let first_file_start = ask_time(format_args!(
			"Please take a look at the file {} and tell me the first second you want included",
			files.first().unwrap()
		));
		let last_file_end = ask_time(format_args!(
			"Please take a look at the file {} and tell me the last second you want included",
			files.last().unwrap()
		));

		let project = Project {
			lecture: ProjectLecture { course, date },
			source: ProjectSource {
				files,
				first_file_start,
				last_file_end
			}
		};
		fs::write(&project_path, toml::to_string(&project).unwrap().as_bytes()).unwrap();
		project
	};

	println!("{}", toml::to_string(&project).unwrap());
}