//! Generate lints for Cargo.toml.

#![cfg_attr(docsrs, feature(doc_cfg))]

extern crate alloc;

use anyhow::Result;
use clap::Parser as _;
use lint_policy::Linter;
use lint_policy::cargo::{LintTable, Manifest};
use strum::IntoEnumIterator as _;

mod cli;
mod diff;
mod group;
mod source;

use cli::Args;
use diff::{Diff, diff};

use crate::group::GroupTable;

/// An empty lint table for unwrapping table references.
static EMPTY_LINTS: LintTable = LintTable::new();
/// An empty group table for unwrapping table references.
static EMPTY_GROUPS: GroupTable = GroupTable::new();

#[cfg_attr(test, expect(clippy::missing_errors_doc, reason = "main function"))]
fn main() -> Result<()> {
	let args = Args::parse();

	let new_lints = args.read_new_source();
	let old_lints = args.read_old_source();

	match old_lints {
		None => {
			for linter in Linter::iter() {
				// section
				#[expect(clippy::print_stdout, reason = "printing out actual output")]
				{
					let mut manifest = Manifest::default();
					manifest
						.workspace
						.lints
						.set_lints_for(linter, LintTable::default());
					print!("{}", toml::to_string(&manifest)?);
				}

				// lints
				if let Some(lints) = new_lints.0.get_lints_for(linter) {
					let mut value = String::new();
					#[expect(clippy::print_stdout, reason = "printing out actual output")]
					for lint in lints {
						_ = serde::Serialize::serialize(
							&lint.1,
							toml::ser::ValueSerializer::new(&mut value),
						)?;
						println!("{} = {}", lint.0, value);
						value.clear();
					}
				}
			}
		}
		Some(old_lints) => {
			for linter in Linter::iter() {
				// section
				#[expect(clippy::print_stdout, reason = "printing out actual output")]
				{
					let mut manifest = Manifest::default();
					manifest
						.workspace
						.lints
						.set_lints_for(linter, LintTable::default());
					print!("{}", toml::to_string(&manifest)?);
				}

				// diff
				let mut value = String::new();
				let old_lints = old_lints.0.get_lints_for(linter).unwrap_or(&EMPTY_LINTS);
				let (new_lints, new_groups) = (
					new_lints.0.get_lints_for(linter).unwrap_or(&EMPTY_LINTS),
					new_lints.1.get_groups_for(linter).unwrap_or(&EMPTY_GROUPS),
				);
				for diff in diff(old_lints, new_lints, new_groups) {
					#[expect(clippy::print_stdout, reason = "printing out actual output")]
					match diff {
						Diff::Added { name, new } => {
							_ = serde::Serialize::serialize(
								&new,
								toml::ser::ValueSerializer::new(&mut value),
							)?;
							println!("+ {name} = {value}");
						}
						Diff::Removed { name, old } => {
							_ = serde::Serialize::serialize(
								&old,
								toml::ser::ValueSerializer::new(&mut value),
							)?;
							println!("- {name} = {value}");
						}
						Diff::Modified { name, old, new } => {
							if !args.ignore_level() {
								_ = serde::Serialize::serialize(
									&old,
									toml::ser::ValueSerializer::new(&mut value),
								)?;
								print!("~ {name} = {value}");
								value.clear();
								_ = serde::Serialize::serialize(
									&new,
									toml::ser::ValueSerializer::new(&mut value),
								)?;
								println!(" => {value}");
							}
						}
					}
					value.clear();
				}
			}
		}
	}

	Ok(())
}