happening/server/src/parsing/identifier_parse.rs

use crate::
{
	// Internal code
	tokenise,
	api,
	//Libs
	HashMap,
	Arc,
	Mutex,
	VecDeque,
	warn,
	debug,
	mpsc::Receiver,
};
use super::keyword_parse;

#[allow(unused_variables)]
pub fn identifier_parse
(
	index: usize,
	identifier: &String,
	tokens: &[tokenise::Token],
	variables: &mut HashMap<String, tokenise::Value>,
	rx: &Receiver<(usize,String)>,
	happening_queue: &Arc<Mutex<VecDeque<api::DataToSend>>>,
) -> Result<(usize,bool),(String,usize)>
{
	let mut sum_index: usize = index;
	let current = variables
		.entry(identifier.clone())
		.or_insert(tokenise::Value::Null)
		.clone();
	let operator = tokenise::get_operator_token(tokens, sum_index)
		.map_err(|err| (err, sum_index))?;
	sum_index += 1;
	let result: bool = match tokenise::get_value_token(tokens, sum_index)
	{
		// An value that can be directly assigned to or compared against the variable
		Ok(value) =>
		{
			sum_index += 1;
			operator_match(&current,value,operator,identifier,variables)
		},
		// Another thing like a choice or an input
		Err(_) =>
		{
			let keyword = tokenise::get_keyword_token(tokens,sum_index)
				.map_err(|err| (err,sum_index))?;
			match keyword.to_lowercase().as_str()
			{
				"choice" =>
				{
					let choice: String;
					(sum_index, choice) = keyword_parse::choice_parse(tokens, index+1, happening_queue,rx)
						.map_err(|err| (err,sum_index+1))?;
					variables.insert(identifier.to_owned(), tokenise::Value::String(choice));
				}
				_ =>
				{
					warn!("Unexpected keyword {keyword}");
				},
			}
			false
		},
	};
	debug!("{variables:?}");
	Ok((sum_index,result))
}

fn operator_match
(
	current: &tokenise::Value,
	value: tokenise::Value,
	operator: tokenise::Operator,
	identifier: &String,
	variables: &mut HashMap<String, tokenise::Value>
)
-> bool
{
	// Operator match box
	match operator
	{
		// Changing a value
		tokenise::Operator::Assignment =>
		{
			variables.insert(identifier.to_owned(), value);
		} ,
		tokenise::Operator::Add =>
		{
			let result: tokenise::Value = match (value.clone(), current)
			{
				(tokenise::Value::Integer(int1),tokenise::Value::Integer(int2)) => tokenise::Value::Integer(int1 + int2),
				(tokenise::Value::String(str1),tokenise::Value::String(str2)) => tokenise::Value::String(format!("{str1}{str2}")),
				_ => value, // otherwise invalid

			};
			variables.insert(identifier.to_owned(), result);
		},
		tokenise::Operator::Sub =>
		{
			let result: tokenise::Value = match (value.clone(), current)
			{
				(tokenise::Value::Integer(int1),tokenise::Value::Integer(int2)) => tokenise::Value::Integer(int2 - int1),
				_ => value, // otherwise invalid

			};
			variables.insert(identifier.to_owned(), result);
		},
		// Comparisons, return a boolean
		tokenise::Operator::Comparison(comp) =>
		{
			let result = match (current, &value)
			{
				// Integer
				(tokenise::Value::Integer(current), tokenise::Value::Integer(comparing)) =>
				{
					match comp
					{
						tokenise::Comparison::Equate =>			current == comparing,
						tokenise::Comparison::Greater =>		current > comparing,
						tokenise::Comparison::Less =>			current < comparing,
						tokenise::Comparison::GreaterOrEqual =>	current >= comparing,
						tokenise::Comparison::LessOrEqual =>	current <= comparing,
					}
				},
				// String
				(tokenise::Value::String(current), tokenise::Value::String(comparing)) =>
				{
					match comp
					{
						tokenise::Comparison::Equate =>			current == comparing,
						tokenise::Comparison::Greater =>		current > comparing,
						tokenise::Comparison::Less =>			current < comparing,
						tokenise::Comparison::GreaterOrEqual =>	current >= comparing,
						tokenise::Comparison::LessOrEqual =>	current <= comparing,
					}
				},
				_ => {
					warn!("Invalid comparison of {current:?} and {value:?}, evaluating false");
					false
				},
			};
			debug!("Comparison {current:?} comp {value:?} evaluates to {result}");
			return result;
		}
	}
	true
}