#!/bin/env python3

import argparse
import ply.lex as lex
import ply.yacc as yacc
import lexer
import tree_print

tokens = lexer.tokens

class ASTnode:
  def __init__(self, typestr, lineno, value = None):
    self.nodetype = typestr
    self.lineno = lineno
    if value is not None:
        self.value = value

class SemData:
    def __init__(self):
        self.in_procedure_def = False
        self.in_function_def = False
        self.return_type = None
        self.parent = None

def p_program1(p):
    'program : statement_list'
    p[0] = ASTnode('program', p.lineno(1))
    p[0].children_definitions = []
    p[0].children_statements = p[1].children_statements

def p_program2(p):
    'program : definition_list statement_list'
    p[0] = ASTnode('program', p.lineno(1))
    p[0].children_definitions = p[1].children_definitions
    p[0].children_statements = p[2].children_statements

def p_statement_list1(p):
    'statement_list : statement'
    p[0] = ASTnode('statement_list', p.lineno(1))
    p[0].children_statements = [ p[1] ]

def p_statement_list2(p):
    'statement_list : statement_list COMMA statement'
    p[0] = p[1]
    p[0].children_statements += [ p[3] ]

def p_definition_list1(p):
    'definition_list : definition'
    p[0] = ASTnode('definition_list', p.lineno(1))
    p[0].children_definitions = [ p[1] ]

def p_definition_list2(p):
    'definition_list : definition_list definition'
    p[0] = p[1]
    p[0].children_definitions += [ p[2] ]

def p_definition(p):
    '''definition : function_definition
                   | procedure_definition
                   | variable_definition'''
    p[0] = p[1]

def p_variable_definition(p):
    'variable_definition : VAR IDENT EQ expression'
    p[0] = ASTnode('variable_definition', p.lineno(1), p[2])
    p[0].child_expression = p[4]

def p_empty(p):
    'empty :'
    pass

def p_variable_definition_list1(p):
    'variable_definition_list : empty'
    p[0] = ASTnode('variable_definition_list', p.lineno(1))
    p[0].children_definitions = []

def p_variable_definition_list2(p):
    'variable_definition_list : variable_definition_list variable_definition'
    p[0] = p[1]
    p[0].children_definitions += [ p[2] ]

def p_function_definition(p):
    '''function_definition : FUNCTION FUNC_IDENT LCURLY formal_list RCURLY RETURN IDENT variable_definition_list IS rvalue END FUNCTION'''
    p[0] = ASTnode('function_definition', p.lineno(2), p[2])
    p[0].children_formals = p[4].children_formals
    p[0].child_return_type = ASTnode('identifier', p.lineno(7), p[7])
    p[0].children_variable_definitions = p[8].children_definitions
    p[0].child_value = p[10]

def p_procedure_definition1(p):
    'procedure_definition : PROCEDURE PROC_IDENT LCURLY formal_list RCURLY variable_definition_list IS statement_list END PROCEDURE'
    p[0] = ASTnode('procedure_definition', p.lineno(2), p[2])
    p[0].children_formals = p[4].children_formals
    p[0].children_variable_definitions = p[6].children_definitions
    p[0].children_statements = p[8].children_statements
    p[0].child_return_type = None

def p_procedure_definition2(p):
    '''procedure_definition : PROCEDURE PROC_IDENT LCURLY formal_list RCURLY RETURN IDENT variable_definition_list IS statement_list END PROCEDURE'''
    p[0] = ASTnode('procedure_definition', p.lineno(2), p[2])
    p[0].children_formals = p[4].children_formals
    p[0].children_variable_definitions = p[8].children_definitions
    p[0].children_statements = p[10].children_statements
    p[0].child_return_type = ASTnode('identifier', p.lineno(7), p[7])

def p_formal_list1(p):
    'formal_list : empty'
    p[0] = ASTnode('formal_list', p.lineno(1))
    p[0].children_formals = []

def p_formal_list2(p):
    'formal_list : formal_arg'
    p[0] = ASTnode('formal_list', p.lineno(1))
    p[0].children_formals = [ p[1] ]

def p_formal_list3(p):
    'formal_list : formal_list COMMA formal_arg'
    p[0] = p[1]
    p[0].children_formals += [ p[3] ]

def p_formal_arg(p):
    'formal_arg : IDENT LSQUARE IDENT RSQUARE'
    p[0] = ASTnode('formal_argument', p.lineno(1))
    p[0].child_variable = ASTnode('identifier', p.lineno(1), p[1])
    p[0].child_type = ASTnode('identifier', p.lineno(3), p[3])

def p_procedure_call1(p):
    'procedure_call : PROC_IDENT LPAREN RPAREN'
    p[0] = ASTnode('procedure_call', p.lineno(1), p[1])
    p[0].children_arguments = []

def p_procedure_call(p):
    '''procedure_call : PROC_IDENT LPAREN arguments RPAREN'''
    p[0] = ASTnode('procedure_call', p.lineno(1), p[1])
    p[0].children_arguments = p[3].children_arguments

def p_arguments1(p):
    'arguments : expression'
    p[0] = ASTnode('arguments', p.lineno(1))
    p[0].children_arguments = [ p[1] ]

def p_arguments2(p):
    'arguments : arguments COMMA expression'
    p[0] = p[1]
    p[0].children_arguments += [ p[3] ]

def p_assignment(p):
    'assignment : lvalue EQ rvalue'
    p[0] = ASTnode('assignment', p.lineno(1))
    p[0].child_lhs = p[1]
    p[0].child_rhs = p[3]

def p_lvalue1(p):
    'lvalue : IDENT'
    p[0] = ASTnode('identifier', p.lineno(1), p[1])

def p_lvalue2(p):
    'lvalue : IDENT DOT IDENT'
    p[0] = ASTnode('attribute_write', p.lineno(1))
    p[0].child_identifier = ASTnode('identifier', p.lineno(1), p[1])
    p[0].child_attribute = ASTnode('identifier', p.lineno(3), p[3])

def p_rvalue(p):
    '''rvalue : expression
              | unless_expression'''
    p[0] = p[1]

def p_print_statement1(p):
    'print_statement : PRINT print_item'
    p[0] = ASTnode('print', p.lineno(1))
    p[0].children_items = [ p[2] ]

def p_print_statement2(p):
    'print_statement : print_statement AMPERSAND print_item'
    p[0] = p[1]
    p[0].children_items += [ p[3] ]

def p_print_item1(p):
    'print_item : STRING'
    p[0] = ASTnode('string_literal', p.lineno(1), p[1])

def p_print_item2(p):
    'print_item : expression'
    p[0] = p[1]

def p_statement1(p):
    '''statement : procedure_call
                 | assignment
                 | print_statement'''
    p[0] = p[1]

def p_statement2(p):
    'statement : DO statement_list UNTIL expression'
    p[0] = ASTnode('do_until', p.lineno(1))
    p[0].children_statements = p[2].children_statements
    p[0].child_condition = p[4]

def p_statement3(p):
    'statement : DO statement_list UNLESS expression DONE'
    p[0] = ASTnode('do_unless', p.lineno(1))
    p[0].children_statements = p[2].children_statements
    p[0].child_condition = p[4]
    p[0].children_otherwise = []

def p_statement4(p):
    'statement : DO statement_list UNLESS expression OTHERWISE statement_list DONE'
    p[0] = ASTnode('do_unless', p.lineno(1))
    p[0].children_statements = p[2].children_statements
    p[0].child_condition = p[4]
    p[0].children_otherwise = p[6].children_statements

def p_statement5(p):
    'statement : RETURN expression'
    p[0] = ASTnode('return', p.lineno(1))
    p[0].child_expression = p[2]

def p_expression1(p):
    'expression : simple_expr'
    p[0] = p[1]

def p_expression2(p):
    '''expression : expression EQ simple_expr
                  | expression LT simple_expr'''
    p[0] = ASTnode('binary_op', p.lineno(2), p[2])
    p[0].child_lhs = p[1]
    p[0].child_rhs = p[3]

def p_simple_expr1(p):
    'simple_expr : term'
    p[0] = p[1]

def p_simple_expr2(p):
    '''simple_expr : simple_expr PLUS term
                   | simple_expr MINUS term'''
    p[0] = ASTnode('binary_op', p.lineno(2), p[2])
    p[0].child_lhs = p[1]
    p[0].child_rhs = p[3]

def p_term1(p):
    'term : factor'
    p[0] = p[1]

def p_term2(p):
    '''term : term MULT factor
            | term DIV factor'''
    p[0] = ASTnode('binary_op', p.lineno(2), p[2])
    p[0].child_lhs = p[1]
    p[0].child_rhs = p[3]

def p_factor1(p):
    'factor : atom'
    p[0] = p[1]

def p_factor2(p):
    '''factor : MINUS atom
              | PLUS atom'''
    p[0] = ASTnode('unary_op', p.lineno(1), p[1])
    p[0].child_atom = p[2]

def p_atom1(p):
    'atom : IDENT'
    p[0] = ASTnode('identifier', p.lineno(1), p[1])

def p_atom2(p):
    'atom : INT_LITERAL'
    p[0] = ASTnode('int_literal', p.lineno(1), p[1])

def p_atom3(p):
    'atom : DATE_LITERAL'
    p[0] = ASTnode('date_literal', p.lineno(1), p[1])

def p_atom4(p):
    'atom : IDENT APOSTROPHE IDENT'
    p[0] = ASTnode('attribute_read', p.lineno(1))
    p[0].child_identifier = ASTnode('identifier', p.lineno(1), p[1])
    p[0].child_attribute = ASTnode('identifier', p.lineno(3), p[3])

def p_atom5(p):
    'atom : LPAREN expression RPAREN'
    p[0] = p[2]

def p_atom6(p):
    '''atom : function_call
            | procedure_call'''
    p[0] = p[1]

def p_function_call1(p):
    'function_call : FUNC_IDENT LPAREN RPAREN'
    p[0] = ASTnode('function_call', p.lineno(1), p[1])
    p[0].children_arguments = []

def p_function_call2(p):
    'function_call : FUNC_IDENT LPAREN arguments RPAREN'
    p[0] = ASTnode('function_call', p.lineno(1), p[1])
    p[0].children_arguments = p[3].children_arguments

def p_unless_expression(p):
    'unless_expression : DO expression UNLESS expression OTHERWISE expression DONE'
    p[0] = ASTnode('unless_expression', p.lineno(1))
    p[0].child_condition = p[4]
    p[0].child_true_expr = p[2]
    p[0].child_false_expr = p[6]

def p_error(p):
    if p is not None:
        print(f"{{{p.lexer.lineno}}}:Syntax Error (token:'{p.value}')")
    else:
        print('Syntax Error at the end of file')
    raise SystemExit


def syntax_check_file(file_path: str, debug: bool) -> ASTnode:
    parser = yacc.yacc()
    with open(file_path, 'r', encoding='utf-8') as file:
        result = parser.parse(file.read(), lexer=lexer.lexer, debug=debug)
    return result


def semantic_check(node: ASTnode, sem_data: SemData):
    is_procedure = False
    is_function = False
    return_type = None

    match node.nodetype:
        case 'attribute_read':
            if node.child_attribute.value not in ['day', 'month', 'year', 'weekday', 'weeknum']:
                print(f'Semantic Error: invalid read attribute \'{node.child_attribute.value}\' at line {node.lineno}')
                raise SystemExit
        case 'attribute_write':
            if node.child_attribute.value not in ['day', 'month', 'year']:
                print(f'Semantic Error: invalid write attribute \'{node.child_attribute.value}\' at line {node.lineno}')
                raise SystemExit
        case 'procedure_definition':
            if node.child_return_type is not None:
                if node.child_return_type.value not in ['int', 'date']:
                    print(f'Semantic Error: procedure definition with invalid return type \'{node.child_return_type.value}\' at line {node.lineno}')
                    raise SystemExit
                return_type = node.child_return_type.value
            for formal in node.children_formals:
                if formal.child_type.value not in ['int', 'date']:
                    print(f'Semantic Error: procedure definition with invalid argument type \'{formal.child_type.value}\' at line {formal.lineno}')
                    raise SystemExit
            is_procedure = True
        case 'function_definition':
            if node.child_return_type is not None:
                if node.child_return_type.value not in ['int', 'date']:
                    print(f'Semantic Error: function definition with invalid return type \'{node.child_return_type.value}\' at line {node.lineno}')
                    raise SystemExit
                return_type = node.child_return_type.value
            for formal in node.children_formals:
                if formal.child_type.value not in ['int', 'date']:
                    print(f'Semantic Error: procedure definition with invalid argument type \'{formal.child_type.value}\' at line {formal.lineno}')
                    raise SystemExit
            is_function = True
        case 'procedure_call':
            if sem_data.in_function_def:
                print(f'Semantic Error: procedure call inside function at line {node.lineno}')
                raise SystemExit
        case 'return':
            if not sem_data.in_procedure_def:
                print(f'Semantic Error: return statement outside of procedure definition at line {node.lineno}')
                raise SystemExit
            if sem_data.return_type is None:
                print(f'Semantic Error: return statement in returnless procedure definition at line {node.lineno}')
                raise SystemExit
        case 'date_literal':
            # date literal can be in variable definition
            if sem_data.parent.nodetype == 'variable_definition':
                pass
            # right side of assignment
            elif sem_data.parent.nodetype == 'assignment':
                if sem_data.parent.child_lhs.nodetype == 'date_literal':
                    print(f'Semantic Error: invalid date literal at line {node.lineno}')
                    raise SystemExit
            # either side of subtraction or left side of addition
            elif sem_data.parent.nodetype == 'binary_op':
                if sem_data.parent.value == '-':
                    pass
                elif sem_data.parent.value == '+':
                    if sem_data.parent.child_rhs.nodetype == 'date_literal':
                        print(f'Semantic Error: invalid date literal at line {node.lineno}')
                        raise SystemExit
                else:
                    print(f'Semantic Error: invalid date literal at line {node.lineno}')
                    raise SystemExit
            else:
                print(f'Semantic Error: invalid date literal at line {node.lineno}')
                raise SystemExit

    if is_procedure or is_function:
        sem_data.in_procedure_def = is_procedure
        sem_data.in_function_def = is_function
        sem_data.return_type = return_type

    temp_parent = sem_data.parent
    sem_data.parent = node

    for name, child in tree_print.get_childvars(node):
        if child is not None:
            semantic_check(child, sem_data)

    sem_data.parent = temp_parent

    if is_procedure or is_function:
        sem_data.in_procedure_def = False
        sem_data.in_function_def = False
        sem_data.return_type = None


if __name__ == '__main__':
    parser = argparse.ArgumentParser()
    parser.add_argument('-d', '--debug', action='store_true', help='debug?')
    group = parser.add_mutually_exclusive_group(required=True)
    group.add_argument('--who', action='store_true', help='print out student IDs and NAMEs of authors')
    group.add_argument('-f', '--file', help='filename to process')

    args = parser.parse_args()

    if args.who:
        print('Author')
        print('  Student ID: 150189237')
        print('  Name:       Oskari Alaranta')
    else:
        ast = syntax_check_file(args.file, args.debug)
        tree_print.treeprint(ast, 'unicode')

        semantic_check(ast, SemData())