#![allow(clippy::manual_range_contains)]
#![warn(rust_2018_idioms)]
#![forbid(elided_lifetimes_in_paths, unsafe_code)]

mod iotro;
mod render;
mod time;

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

static MEM_LIMIT: RwLock<String> = RwLock::new(String::new());

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

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

	#[clap(short, long, default_value = "2G")]
	mem_limit: String
}

#[allow(non_camel_case_types, clippy::upper_case_acronyms)]
#[derive(Clone, Copy, Deserialize, Eq, Ord, PartialEq, PartialOrd, Serialize)]
enum Resolution {
	/// 640x360
	nHD,
	/// 1280x720
	HD,
	/// 1920x1080
	FullHD,
	/// 2560x1440
	WQHD,
	/// 3840x2160
	UHD
}

impl Resolution {
	fn width(self) -> usize {
		match self {
			Self::nHD => 640,
			Self::HD => 1280,
			Self::FullHD => 1920,
			Self::WQHD => 2560,
			Self::UHD => 3840
		}
	}

	fn height(self) -> usize {
		match self {
			Self::nHD => 360,
			Self::HD => 720,
			Self::FullHD => 1080,
			Self::WQHD => 1440,
			Self::UHD => 2160
		}
	}
}

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

#[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 = "Option<DisplayFromStr>")]
	start: Option<Time>,
	#[serde_as(as = "Option<DisplayFromStr>")]
	end: Option<Time>,
	#[serde_as(as = "Vec<(DisplayFromStr, DisplayFromStr)>")]
	fast: Vec<(Time, Time)>,

	metadata: Option<ProjectSourceMetadata>
}

#[serde_as]
#[derive(Deserialize, Serialize)]
struct ProjectSourceMetadata {
	/// The duration of the source video.
	#[serde_as(as = "DisplayFromStr")]
	source_duration: Time,
	/// The FPS of the source video.
	#[serde_as(as = "DisplayFromStr")]
	source_fps: Rational,
	/// The time base of the source video.
	#[serde_as(as = "DisplayFromStr")]
	source_tbn: Rational,
	/// The resolution of the source video.
	source_res: Resolution,
	/// The sample rate of the source audio.
	source_sample_rate: u32
}

#[derive(Default, Deserialize, Serialize)]
struct ProjectProgress {
	preprocessed: bool,
	asked_start_end: bool,
	asked_fast: bool,
	rendered: bool,
	transcoded: BTreeSet<Resolution>
}

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();
	*(MEM_LIMIT.write().unwrap()) = args.mem_limit;

	// 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 mut 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 project = Project {
			lecture: ProjectLecture { course, date },
			source: ProjectSource {
				files,
				start: None,
				end: None,
				fast: Vec::new(),
				metadata: None
			},
			progress: Default::default()
		};
		fs::write(&project_path, toml::to_string(&project).unwrap().as_bytes()).unwrap();
		project
	};

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

	let renderer = Renderer::new(&directory, &project).unwrap();
	let recording = renderer.recording_mp4();

	// preprocess the video
	if !project.progress.preprocessed {
		renderer.preprocess(&mut project).unwrap();
		project.progress.preprocessed = true;

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

	// ask the user about start and end times
	if !project.progress.asked_start_end {
		project.source.start = Some(ask_time(format_args!(
			"Please take a look at the file {recording} and tell me the first second you want included"
		)));
		project.source.end = Some(ask_time(format_args!(
			"Please take a look at the file {recording} and tell me the last second you want included"
		)));
		project.progress.asked_start_end = true;

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

	// ask the user about fast forward times
	if !project.progress.asked_fast {
		loop {
			let start = ask_time(format_args!(
				"Please take a look at the file {recording} and tell me the first second you want fast-forwarded. You may reply with `0` if there are no more fast-forward sections"
			));
			if start.seconds == 0 && start.micros == 0 {
				break;
			}
			let end = ask_time(format_args!(
				"Please tell me the last second you want fast-forwarded"
			));
			project.source.fast.push((start, end));
		}
		project.progress.asked_fast = true;

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

	let video = renderer.render(&mut project).unwrap();
	println!("\x1B[1m ==> DONE :)\x1B[0m Video: {video}");
}