// SPDX-FileCopyrightText: Copyright (C) 2024 Roland Csaszar
// SPDX-License-Identifier: MPL-2.0
//
// Project:  token-string
// File:     test_builder.rs
// Date:     24.Nov.2024
// =============================================================================
//! Test the concatenation of `TokenStrings`s.

#![expect(clippy::tests_outside_test_module, reason = "tests directory")]

mod errors {

	use assert2::{check, let_assert};
	use token_string::{Builder, MAX_LENGTH, TkStrError, TokenString};

	#[test]
	fn too_many() {
		let_assert!(Ok(s1) = TokenString::try_from("Hello"));
		let_assert!(Ok(s2) = TokenString::try_from(", "));
		let_assert!(Ok(s3) = TokenString::try_from("world"));
		let_assert!(Ok(s4) = TokenString::try_from("!"));
		let mut builder = Builder::<'_, 3>::new(&s1);
		let_assert!(Ok(_) = builder.concat_checked(&s2));
		let_assert!(Ok(_) = builder.concat_checked(&s3));
		let_assert!(Err(e) = builder.concat_checked(&s4));
		check!(e == TkStrError::TooMany(3));
	}

	#[test]
	fn too_big() {
		let_assert!(Ok(s1) = TokenString::try_from("Hello"));
		let_assert!(Ok(s2) = TokenString::try_from(", "));
		let_assert!(Ok(s3) = TokenString::try_from("world"));
		let big = vec![b'1'; MAX_LENGTH].into_boxed_slice();
		let_assert!(Ok(s4) = TokenString::try_from(&*big));
		let mut builder = Builder::<'_, 4>::new(&s1);
		let_assert!(Ok(_) = builder.concat_checked(&s2));
		let_assert!(Ok(_) = builder.concat_checked(&s3));
		let_assert!(Err(e) = builder.concat_checked(&s4));
		check!(e == TkStrError::TooBig(65547));
	}

	#[test]
	fn too_many_panic() {
		let_assert!(Ok(s1) = TokenString::try_from("Hello"));
		let_assert!(Ok(s2) = TokenString::try_from(", "));
		let_assert!(Ok(s3) = TokenString::try_from("world"));
		let_assert!(Ok(s4) = TokenString::try_from("!"));

		let_assert!(
			Err(panics) = std::panic::catch_unwind(|| {
				let mut builder = Builder::<'_, 3>::new(&s1);
				let_assert!(Ok(_) = builder.concat_checked(&s2));
				let_assert!(Ok(_) = builder.concat_checked(&s3));
				let _c = builder.concat_unchecked(&s4);
			})
		);
		let_assert!(Some(msg) = panics.downcast_ref::<&str>());
		check!(
			msg == &"more strings concatenated than reserved space in Builder"
		);
	}

	#[test]
	fn not_zero_panic() {
		let_assert!(Ok(s1) = TokenString::try_from("Hello"));

		let_assert!(
			Err(panics) = std::panic::catch_unwind(|| {
				let mut _builder = Builder::<'_, 0>::new(&s1);
			})
		);
		let_assert!(Some(msg) = panics.downcast_ref::<&str>());
		check!(msg == &"the number of elements must not be 0");
	}
}

mod func {
	use assert2::{check, let_assert};
	use token_string::{Builder, Collect as _, Concat as _, TokenString};

	#[test]
	fn concat_collect() {
		let_assert!(Ok(s1) = TokenString::try_from("Hello"));
		let_assert!(Ok(s2) = TokenString::try_from(", "));
		let_assert!(Ok(s3) = TokenString::try_from("world"));
		let_assert!(Ok(s4) = TokenString::try_from("!"));

		let mut builder = Builder::<'_, 4>::new(&s1);
		let builder_2 = builder.concat(&s2).concat(&s3).concat(&s4);
		let_assert!(Ok(res) = builder_2.collect());
		check!(&res == "Hello, world!");
	}

	#[test]
	fn collect_unchecked_concat() {
		let_assert!(Ok(s1) = TokenString::try_from("Hello"));
		let_assert!(Ok(s2) = TokenString::try_from(", "));
		let_assert!(Ok(s3) = TokenString::try_from("world"));
		let_assert!(Ok(s4) = TokenString::try_from("!"));

		let mut builder = Builder::<'_, 4>::new(&s1);
		let builder_2 = builder
			.concat_unchecked(&s2)
			.concat_unchecked(&s3)
			.concat_unchecked(&s4);
		let_assert!(Ok(res) = builder_2.collect());
		check!(&res == "Hello, world!");
	}

	#[test]
	fn to_string() {
		let_assert!(Ok(s1) = TokenString::try_from("Hello"));
		let_assert!(Ok(s2) = TokenString::try_from(", "));
		let_assert!(Ok(s3) = TokenString::try_from("world"));
		let_assert!(Ok(s4) = TokenString::try_from("!"));

		let mut builder = Builder::<'_, 4>::new(&s1);
		let_assert!(
			Ok(builder_2) = builder.concat(&s2).concat(&s3).concat(&s4)
		);
		check!(
			builder_2.to_string()
				== "Builder < 'Hello' + ', ' + 'world' + '!' >"
		);
	}
}

mod properties {
	use assert2::let_assert;
	use proptest::prelude::*;
	use token_string::{Builder, TokenString};

	fn vec_of_string(len: usize) -> impl Strategy<Value = Vec<String>> {
		prop::collection::vec(".*", 1 .. len).prop_flat_map(Just)
	}

	proptest! {

	#[test]
	fn concat_2(a in ".*", b in ".*") {
		let_assert!(Ok(s1) = TokenString::try_from(&a));
		let_assert!(Ok(s2) = TokenString::try_from(&b));
		let mut builder = Builder::<'_, 2>::new(&s1);
		let_assert!(Ok(c) = builder.concat_checked(&s2));
		let_assert!(Ok(res) = c.collect_checked());
		let mut exp = a;
		exp.push_str(&b);
		prop_assert!(res == exp);
	}

	#[test]
	#[cfg_attr(miri, ignore)] // takes too long for miri - 10 hours!
	fn concat_many(v in vec_of_string(100)) {
		let strings: Vec<TokenString> = v.iter()
			.map(|s| {TokenString::from_str_unchecked(s)}).collect();

		let mut builder = Builder::<'_, 100>::new(&strings[0]);
		let mut exp = strings[0].as_string();
		for s in strings.iter().skip(1) {
			let_assert!(Ok(_c) = builder.concat_checked(s));
			exp.push_str(s.as_str());
		}
		let_assert!(Ok(res) = builder.collect_checked());
		prop_assert!(res == exp);
	}

	}
}