emmylua_ls 0.15.0

use emmylua_code_analysis::{InferGuard, LuaType};
use emmylua_parser::{
    BinaryOperator, LuaAstNode, LuaBinaryExpr, LuaBlock, LuaLiteralExpr, LuaSyntaxKind,
};

use crate::handlers::completion::{
    completion_builder::CompletionBuilder, providers::function_provider::dispatch_type,
};

pub fn add_completion(builder: &mut CompletionBuilder) -> Option<()> {
    if builder.is_cancelled() {
        return None;
    }
    if !check_can_add_completion(builder) {
        return None;
    }
    let types = get_token_should_type(builder)?;
    for typ in &types {
        dispatch_type(builder, typ.clone(), &InferGuard::new());
    }
    if !types.is_empty() && !builder.is_invoked() {
        builder.stop_here();
    }
    Some(())
}

fn check_can_add_completion(builder: &CompletionBuilder) -> bool {
    // 允许空格字符触发补全
    if builder.is_space_trigger_character {
        return true;
    }

    true
}

fn get_token_should_type(builder: &mut CompletionBuilder) -> Option<Vec<LuaType>> {
    let token = builder.trigger_token.clone();
    let mut parent_node = token.parent()?;
    // 如果父节点是块, 则可能是输入未完全, 语法树缺失
    if LuaBlock::cast(parent_node.clone()).is_some() {
        if let Some(node) = token.prev_token()?.parent()
            && LuaBinaryExpr::can_cast(node.kind().into())
        {
            parent_node = node;
        }
    } else {
        // 输入`""`时允许往上找
        if LuaLiteralExpr::can_cast(parent_node.kind().into()) {
            parent_node = parent_node.parent()?;
        }
    }

    if Into::<LuaSyntaxKind>::into(parent_node.kind()) == LuaSyntaxKind::BinaryExpr {
        let binary_expr = LuaBinaryExpr::cast(parent_node)?;
        let op_token = binary_expr.get_op_token()?;
        let op = op_token.get_op();
        if op == BinaryOperator::OpEq || op == BinaryOperator::OpNe {
            let left = binary_expr.get_left_expr()?;
            let left_type = builder.semantic_model.infer_expr(left);

            if let Ok(typ) = left_type {
                return Some(vec![typ]);
            }
        }
    }

    None
}