use fancy_regex::Regex;

use crate::{Tokenizer, split::regex_segment};

#[test]
fn basic() {
	let re = Regex::new(r"[,;]").unwrap();
	let text = "apple,banana;cherry";
	let result = regex_segment(&re, text);
	assert_eq!(result, vec!["apple", ",", "banana", ";", "cherry"]);
}

#[test]
fn empty_string() {
	let re = Regex::new(r"[,;]").unwrap();
	let text = "";
	let result = regex_segment(&re, text);
	assert_eq!(result, Vec::<&str>::new());
}

#[test]
fn no_matches() {
	let re = Regex::new(r"[,;]").unwrap();
	let text = "apple banana cherry";
	let result = regex_segment(&re, text);
	assert_eq!(result, vec!["apple banana cherry"]);
}

#[test]
fn only_matches() {
	let re = Regex::new(r"[,;]").unwrap();
	let text = ",;,";
	let result = regex_segment(&re, text);
	assert_eq!(result, vec![",", ";", ","]);
}

#[test]
fn starts_with_match() {
	let re = Regex::new(r"[,;]").unwrap();
	let text = ",apple;banana";
	let result = regex_segment(&re, text);
	assert_eq!(result, vec![",", "apple", ";", "banana"]);
}

#[test]
fn ends_with_match() {
	let re = Regex::new(r"[,;]").unwrap();
	let text = "apple,banana;";
	let result = regex_segment(&re, text);
	assert_eq!(result, vec!["apple", ",", "banana", ";"]);
}

#[test]
fn consecutive_matches() {
	let re = Regex::new(r"[,;]").unwrap();
	let text = "apple,,banana";
	let result = regex_segment(&re, text);
	assert_eq!(result, vec!["apple", ",", ",", "banana"]);
}

#[test]
fn word_boundaries() {
	let re = Regex::new(r"\b").unwrap();
	let text = "hello world";
	let result = regex_segment(&re, text);
	// Word boundaries are zero-width, so we get empty matches between word chars and non-word chars
	assert_eq!(result, vec!["hello", " ", "world"]);
}

#[test]
fn digits() {
	let re = Regex::new(r"\d+").unwrap();
	let text = "abc123def456ghi";
	let result = regex_segment(&re, text);
	assert_eq!(result, vec!["abc", "123", "def", "456", "ghi"]);
}

#[test]
fn special_tokens() {
	let re = Regex::new(Tokenizer::SPECIAL_REGEX).unwrap();
	let text = "Hello <|user_start|>world<|user_end|> test";
	let result = regex_segment(&re, text);
	assert_eq!(
		result,
		vec!["Hello ", "<|user_start|>", "world", "<|user_end|>", " test"]
	);
}

#[test]
fn unicode() {
	let re = Regex::new(r"[=�=�]+").unwrap();
	let text = "Hello=�world=�test";
	let result = regex_segment(&re, text);
	assert_eq!(result, vec!["Hello", "=�", "world", "=�", "test"]);
}

#[test]
fn single_char() {
	let re = Regex::new(r"x").unwrap();
	let text = "x";
	let result = regex_segment(&re, text);
	assert_eq!(result, vec!["x"]);
}

#[test]
fn multichar_match() {
	let re = Regex::new(r"abc").unwrap();
	let text = "123abc456abc789";
	let result = regex_segment(&re, text);
	assert_eq!(result, vec!["123", "abc", "456", "abc", "789"]);
}

#[test]
fn bos_token() {
	let re = Regex::new(Tokenizer::SPECIAL_REGEX).unwrap();
	let text = "<|bos|>This is a document";
	let result = regex_segment(&re, text);
	assert_eq!(result, vec!["<|bos|>", "This is a document"]);
}

#[test]
fn conversation_flow() {
	let re = Regex::new(Tokenizer::SPECIAL_REGEX).unwrap();
	let text = "<|user_start|>Hello<|user_end|><|assistant_start|>Hi there!<|assistant_end|>";
	let result = regex_segment(&re, text);
	assert_eq!(
		result,
		vec![
			"<|user_start|>",
			"Hello",
			"<|user_end|>",
			"<|assistant_start|>",
			"Hi there!",
			"<|assistant_end|>"
		]
	);
}

#[test]
fn python_code_block() {
	let re = Regex::new(Tokenizer::SPECIAL_REGEX).unwrap();
	let text = "Code: <|python_start|>print('hello')<|python_end|> Output: <|output_start|>hello<|output_end|>";
	let result = regex_segment(&re, text);
	assert_eq!(
		result,
		vec![
			"Code: ",
			"<|python_start|>",
			"print('hello')",
			"<|python_end|>",
			" Output: ",
			"<|output_start|>",
			"hello",
			"<|output_end|>"
		]
	);
}

#[test]
fn mixed_special_tokens() {
	let re = Regex::new(Tokenizer::SPECIAL_REGEX).unwrap();
	let text =
		"<|bos|><|user_start|>Question<|user_end|><|assistant_start|>Answer<|assistant_end|>";
	let result = regex_segment(&re, text);
	assert_eq!(
		result,
		vec![
			"<|bos|>",
			"<|user_start|>",
			"Question",
			"<|user_end|>",
			"<|assistant_start|>",
			"Answer",
			"<|assistant_end|>"
		]
	);
}

#[test]
fn no_special_tokens() {
	let re = Regex::new(Tokenizer::SPECIAL_REGEX).unwrap();
	let text = "This is just regular text with no special tokens";
	let result = regex_segment(&re, text);
	assert_eq!(
		result,
		vec!["This is just regular text with no special tokens"]
	);
}

#[test]
fn malformed_special_tokens() {
	let re = Regex::new(Tokenizer::SPECIAL_REGEX).unwrap();
	let text = "This has <|invalid_token> and <user_start> which shouldn't match";
	let result = regex_segment(&re, text);
	assert_eq!(
		result,
		vec!["This has <|invalid_token> and <user_start> which shouldn't match"]
	);
}

#[test]
fn special_tokens_with_whitespace() {
	let re = Regex::new(Tokenizer::SPECIAL_REGEX).unwrap();
	let text = " <|bos|> \n<|user_start|>\tHello\n<|user_end|> ";
	let result = regex_segment(&re, text);
	assert_eq!(
		result,
		vec![
			" ",
			"<|bos|>",
			" \n",
			"<|user_start|>",
			"\tHello\n",
			"<|user_end|>",
			" "
		]
	);
}

#[test]
fn only_special_tokens() {
	let re = Regex::new(Tokenizer::SPECIAL_REGEX).unwrap();
	let text = "<|bos|><|user_start|><|user_end|>";
	let result = regex_segment(&re, text);
	assert_eq!(result, vec!["<|bos|>", "<|user_start|>", "<|user_end|>"]);
}

#[test]
fn nested() {
	let re = Regex::new(Tokenizer::SPECIAL_REGEX).unwrap();
	let text = "<|<|bos|>|>";
	let result = regex_segment(&re, text);
	assert_eq!(result, vec!["<|", "<|bos|>", "|>"]);
}