use crate::ast::add_expression::AddExpression;
use crate::ast::call::Call;
use crate::ast::double_literal::DoubleLiteral;
use crate::ast::identifier::Identifier;
use crate::ast::integer_literal::IntegerLiteral;
use crate::ast::ir_builder::IrBuilder;
use crate::ast::negative_expression::NegativeExpression;
use crate::ast::string_literal::StringLiteral;
use crate::ast::subtract_expression::SubtractExpression;
use crate::diagnostic::Diagnostic;
use crate::ir::ir_assign::IrAssign;
use crate::ir::ir_expression::IrExpression;
use crate::ir::ir_operation::IrOperation;
use crate::ir::ir_statement::IrStatement;
use crate::ir::ir_variable::IrVariable;
use crate::source_range::SourceRange;
use crate::symbol_table::SymbolTable;
use crate::type_info::TypeInfo;
use std::cell::RefCell;
use std::rc::Rc;

pub enum Expression {
    Add(AddExpression),
    Subtract(SubtractExpression),
    Negative(NegativeExpression),
    Call(Call),
    Identifier(Identifier),
    Integer(IntegerLiteral),
    Double(DoubleLiteral),
    String(StringLiteral),
}

impl Expression {
    pub fn gather_declared_names(
        &mut self,
        symbol_table: &mut SymbolTable,
    ) -> Result<(), Vec<Diagnostic>> {
        match self {
            Expression::Add(add_expression) => add_expression.gather_declared_names(symbol_table),
            Expression::Subtract(subtract_expression) => {
                subtract_expression.gather_declared_names(symbol_table)
            }
            Expression::Negative(negative_expression) => {
                negative_expression.gather_declared_names(symbol_table)
            }
            Expression::Call(call) => call.gather_declared_names(symbol_table),
            Expression::Identifier(identifier) => identifier.gather_declared_names(symbol_table),
            Expression::Integer(_) => Ok(()),
            Expression::Double(_) => Ok(()),
            Expression::String(_) => Ok(()),
        }
    }

    pub fn check_name_usages(&mut self, symbol_table: &SymbolTable) -> Result<(), Vec<Diagnostic>> {
        match self {
            Expression::Add(add_expression) => add_expression.check_name_usages(symbol_table),
            Expression::Subtract(subtract_expression) => {
                subtract_expression.check_name_usages(symbol_table)
            }
            Expression::Negative(negative_expression) => {
                negative_expression.check_name_usages(symbol_table)
            }
            Expression::Call(call) => call.check_name_usages(symbol_table),
            Expression::Identifier(identifier) => identifier.check_name_usages(symbol_table),
            Expression::Integer(_) => Ok(()),
            Expression::Double(_) => Ok(()),
            Expression::String(_) => Ok(()),
        }
    }

    pub fn type_check(&mut self, symbol_table: &SymbolTable) -> Result<(), Vec<Diagnostic>> {
        match self {
            Expression::Add(add_expression) => add_expression.type_check(symbol_table),
            Expression::Subtract(subtract_expression) => {
                subtract_expression.type_check(symbol_table)
            }
            Expression::Negative(negative_expression) => {
                negative_expression.type_check(symbol_table)
            }
            Expression::Call(call) => call.type_check(symbol_table),
            Expression::Identifier(identifier) => identifier.type_check(symbol_table),
            Expression::Integer(_) => Ok(()),
            Expression::Double(_) => Ok(()),
            Expression::String(_) => Ok(()),
        }
    }

    pub fn type_info(&self) -> &TypeInfo {
        match self {
            Expression::Add(add_expression) => add_expression.type_info(),
            Expression::Subtract(subtract_expression) => subtract_expression.type_info(),
            Expression::Negative(negative_expression) => negative_expression.type_info(),
            Expression::Call(call) => call.return_type_info(),
            Expression::Identifier(identifier) => identifier.type_info(),
            Expression::Integer(integer_literal) => integer_literal.type_info(),
            Expression::Double(double_literal) => double_literal.type_info(),
            Expression::String(string_literal) => string_literal.type_info(),
        }
    }

    pub fn source_range(&self) -> &SourceRange {
        match self {
            Expression::Add(additive_expression) => additive_expression.source_range(),
            Expression::Subtract(subtract_expression) => subtract_expression.source_range(),
            Expression::Negative(negative_expression) => negative_expression.source_range(),
            Expression::Call(call) => call.source_range(),
            Expression::Identifier(identifier) => identifier.source_range(),
            Expression::Integer(integer_literal) => integer_literal.source_range(),
            Expression::Double(double_literal) => double_literal.source_range(),
            Expression::String(string_literal) => string_literal.source_range(),
        }
    }

    pub fn to_ir(
        &self,
        builder: &mut IrBuilder,
        symbol_table: &SymbolTable,
    ) -> Option<IrExpression> {
        match self {
            Expression::Call(call) => {
                let ir_call = call.to_ir(builder, symbol_table);
                if matches!(call.return_type_info(), TypeInfo::Void) {
                    builder
                        .current_block_mut()
                        .add_statement(IrStatement::Call(ir_call));
                    None
                } else {
                    let t_var = IrVariable::new_vr(
                        builder.new_t_var().into(),
                        builder.current_block().id(),
                        call.return_type_info(),
                    );
                    let as_rc = Rc::new(RefCell::new(t_var));
                    let assign = IrAssign::new(as_rc.clone(), IrOperation::Call(ir_call));
                    builder
                        .current_block_mut()
                        .add_statement(IrStatement::Assign(assign));
                    Some(IrExpression::Variable(as_rc))
                }
            }
            Expression::Integer(integer_literal) => {
                Some(IrExpression::Int(integer_literal.value()))
            }
            Expression::Double(double_literal) => {
                Some(IrExpression::Double(double_literal.value()))
            }
            Expression::String(string_literal) => {
                Some(IrExpression::String(string_literal.content().into()))
            }
            Expression::Identifier(identifier) => {
                let expressible_symbol = identifier.expressible_symbol();
                Some(expressible_symbol.ir_expression(builder))
            }
            Expression::Add(additive_expression) => {
                let ir_add = additive_expression.to_ir(builder, symbol_table);
                let t_var = IrVariable::new_vr(
                    builder.new_t_var().into(),
                    builder.current_block().id(),
                    additive_expression.type_info(),
                );
                let as_rc = Rc::new(RefCell::new(t_var));
                let assign = IrAssign::new(as_rc.clone(), IrOperation::Add(ir_add));
                builder
                    .current_block_mut()
                    .add_statement(IrStatement::Assign(assign));
                Some(IrExpression::Variable(as_rc))
            }
            Expression::Subtract(subtract_expression) => {
                Some(subtract_expression.to_ir_expression(builder, symbol_table))
            }
            Expression::Negative(negative_expression) => {
                Some(negative_expression.to_ir(builder, symbol_table))
            }
        }
    }
}