/* This file contains auxiliary functions that turn LDPL identifiers / expressions into C / C++ identifiers / expressions */

// +---------------------------------------------+
// | TODO: comment and format this file properly |
// +---------------------------------------------+

// Given a full variable (with accesses and everything, like foo:0:'hi there' or bar) returns
// the C++ representation of said variable in order to be accessed.
string get_c_variable(compiler_state &state, string &variable)
{
    // We want to get two things in order to create the correct C++ representation
    // of a 'full variable': the variable name and all the indexess we are trying
    // to access that correspond to this particular variable (because we could have
    // foo number list list and bar number list and try to access foo:bar:0:1. In this
    // case, we would be interested in getting 'foo', 'bar:0' and '1'.
    string var_name;
    vector<string> indexes;
    // We use the split_vector function to get these values into our variables.
    split_vector(variable, var_name, indexes, state);
    // We 'fix' the variable name, turning all characters not accepted by C++ into
    // LDPL codes that C++ does accept.
    var_name = fix_identifier(var_name, true, state);
    // If split_vector didn't return any indexes, then we are dealing with a scalar
    // variable. We just return the C++ variable name and we are done.
    if (indexes.empty())
        return var_name;
    // If our indexes vector is not empty, however, we recreate the correct C++
    // container access, with one dimension for each value in our indexes vector.
    for (size_t i = 0; i < indexes.size(); ++i)
        var_name += '[' + get_c_expression(state, indexes[i]) + ']';
    // Once we are done, we return the variable name.
    return var_name;
}

string get_c_expression(compiler_state &state, string &expression)
{
    if (is_scalar_variable(expression, state) || variable_exists(expression, state))
        return get_c_variable(state, expression);
    is_number(expression); // We fix the expression should it be a number literal
    return expression;
}

// text must be a TEXT or a TEXT variable
string get_c_char_array(compiler_state &state, string &text)
{
    if (is_txt_var(text, state))
        return get_c_variable(state, text) + ".str_rep().c_str()";
    return text;
}

string get_c_string(compiler_state &state, string &expression)
{
    string c_expression = get_c_expression(state, expression);
    if (is_num_expr(expression, state))
        return "to_ldpl_string(" + c_expression + ")";
    return c_expression;
}

string get_c_number(compiler_state &state, string &expression)
{
    string c_expression = get_c_expression(state, expression);
    if (is_txt_expr(expression, state))
        return "to_number(" + c_expression + ")";
    return c_expression;
}

// Returns [ERROR] if invalid condtion, otherwise returns C++ condition
string get_c_condition(compiler_state &state, vector<string> tokens)
{
    unsigned int ct = 0;
    string condition = get_c_condition(state, tokens, ct);
    if (ct < tokens.size())
        return "[ERROR]";
    return condition;
}

#define MATCH(x)                               \
    if (ct < tokens.size() && tokens[ct] == x) \
        ct++;                                  \
    else                                       \
        return "[ERROR]";

string get_c_condition(compiler_state &state, vector<string> tokens, unsigned int &ct)
{
    if (ct >= tokens.size())
        return "[ERROR]";
    string condition;
    if (tokens[ct] == "(")
    {
        MATCH("(");
        condition = get_c_condition(state, tokens, ct);
        if (condition == "[ERROR]")
            return condition;
        MATCH(")");
        condition = "(" + condition + ")";
    }
    else
    {
        string first_value = tokens[ct];
        string second_value;
        string rel_op;
        ct++; // We validate the token after we get the second value
        if (tokens[ct] == "IS")
        {
            MATCH("IS");
            if (tokens[ct] == "EQUAL")
            {
                MATCH("EQUAL");
                MATCH("TO");
                rel_op = "EQUAL TO";
            }
            else if (tokens[ct] == "NOT")
            {
                MATCH("NOT");
                MATCH("EQUAL");
                MATCH("TO");
                rel_op = "NOT EQUAL TO";
            }
            else if (tokens[ct] == "GREATER")
            {
                MATCH("GREATER");
                MATCH("THAN");
                if (ct + 1 < tokens.size() && tokens[ct + 1] == "EQUAL")
                {
                    // We check the next token instead of the curent one
                    // because "OR" could be a variable after "GREATER THAN"
                    MATCH("OR");
                    MATCH("EQUAL");
                    MATCH("TO");
                    rel_op = "GREATER THAN OR EQUAL TO";
                }
                else
                {
                    rel_op = "GREATER THAN";
                }
            }
            else if (tokens[ct] == "LESS")
            {
                MATCH("LESS");
                MATCH("THAN");
                if (ct + 1 < tokens.size() && tokens[ct + 1] == "EQUAL")
                {
                    // We check the next token instead of the curent one
                    // because "OR" could be a variable after "LESS THAN"
                    MATCH("OR");
                    MATCH("EQUAL");
                    MATCH("TO");
                    rel_op = "LESS THAN OR EQUAL TO";
                }
                else
                {
                    rel_op = "LESS THAN";
                }
            }
            else
            {
                return "[ERROR]";
            }

            second_value = tokens[ct];
            ++ct;

            string type;
            if (is_num_expr(first_value, state) && is_num_expr(second_value, state))
                type = "NUMBER";
            else if (is_txt_expr(first_value, state) && is_txt_expr(second_value, state))
                type = "TEXT";
            else if (is_num_map(first_value, state) && is_num_map(second_value, state))
                type = "NUMBER MAP";
            else if (is_txt_map(first_value, state) && is_txt_map(second_value, state))
                type = "TEXT MAP";
            else if (is_num_list(first_value, state) && is_num_list(second_value, state))
                type = "NUMBER LIST";
            else if (is_txt_list(first_value, state) && is_txt_list(second_value, state))
                type = "TEXT LIST";
            else if (is_list_list(first_value, state) && is_list_list(second_value, state) && variable_type(first_value, state) == variable_type(second_value, state))
                type = "LIST LIST";
            else if (is_map_map(first_value, state) && is_map_map(second_value, state) && variable_type(first_value, state) == variable_type(second_value, state))
                type = "MAP MAP";
            else
                return "[ERROR]";

            first_value = get_c_expression(state, first_value);
            second_value = get_c_expression(state, second_value);
            if (type == "NUMBER")
            {
                if (rel_op == "EQUAL TO")
                    condition = "num_equal(" + first_value + ", " + second_value + ")";
                else if (rel_op == "NOT EQUAL TO")
                    condition = "!num_equal(" + first_value + ", " + second_value + ")";
                else if (rel_op == "GREATER THAN")
                    condition = first_value + " > " + second_value;
                else if (rel_op == "LESS THAN")
                    condition = first_value + " < " + second_value;
                else if (rel_op == "GREATER THAN OR EQUAL TO")
                    condition = "(" + first_value + " > " + second_value + " || num_equal(" + first_value + ", " + second_value + "))";
                else
                    condition = "(" + first_value + " < " + second_value + " || num_equal(" + first_value + ", " + second_value + "))";
            }
            else if (type == "TEXT")
            {
                if (rel_op == "EQUAL TO")
                    condition = "str_cmp(" + first_value + ", " + second_value + ") == 0";
                else if (rel_op == "NOT EQUAL TO")
                    condition = "str_cmp(" + first_value + ", " + second_value + ") != 0";
                else if (rel_op == "GREATER THAN")
                    condition = "str_cmp(" + first_value + ", " + second_value + ") > 0";
                else if (rel_op == "LESS THAN")
                    condition = "str_cmp(" + first_value + ", " + second_value + ") < 0";
                else if (rel_op == "GREATER THAN OR EQUAL TO")
                    condition = "str_cmp(" + first_value + ", " + second_value + ") >= 0";
                else if (rel_op == "LESS THAN OR EQUAL TO")
                    condition = "str_cmp(" + first_value + ", " + second_value + ") <= 0";
                else
                    return "[ERROR]";
            }
            else
            {
                first_value += ".inner_collection";
                second_value += ".inner_collection";
                if (rel_op == "EQUAL TO")
                    condition = first_value + " == " + second_value;
                else if (rel_op == "NOT EQUAL TO")
                    condition = first_value + " != " + second_value;
                else // >, >, <= and >= are only valid in NUMBER and TEXT
                    return "[ERROR]";
            }
        }
        else
        {
            if (tokens[ct] == "IN")
            {
                MATCH("IN");
                rel_op = "IN";
            }
            else if (tokens[ct] == "NOT")
            {
                MATCH("NOT");
                MATCH("IN");
                rel_op = "NOT IN";
            }

            second_value = tokens[ct];
            ++ct;
            string type;
            if (is_num_expr(first_value, state) && is_num_list(second_value, state))
                type = "NUM-IN-NUM-LIST";
            else if (is_num_expr(first_value, state) && is_txt_list(second_value, state))
                type = "NUM-IN-TEXT-LIST";
            else if (is_txt_expr(first_value, state) && is_num_list(second_value, state))
                type = "TEXT-IN-NUM-LIST";
            else if (is_txt_expr(first_value, state) && is_txt_list(second_value, state))
                type = "TEXT-IN-TEXT-LIST";
            else if (is_num_expr(first_value, state) && is_map(second_value, state))
                type = "NUM-IN-MAP";
            else if (is_string(first_value) && is_map(second_value, state))
                type = "STR-IN-MAP";
            else if (is_txt_var(first_value, state) && is_map(second_value, state))
                type = "TEXTVAR-IN-MAP";
            else
                return "[ERROR]";

            first_value = get_c_expression(state, first_value);
            second_value = get_c_expression(state, second_value);
            if (type == "NUM-IN-NUM-LIST")
            {
                if (rel_op == "IN")
                    condition = "find(" + second_value + ".inner_collection.begin(), " + second_value + ".inner_collection.end(), (ldpl_number) " + first_value + ") != " + second_value + ".inner_collection.end()";
                else if (rel_op == "NOT IN")
                    condition = "find(" + second_value + ".inner_collection.begin(), " + second_value + ".inner_collection.end(), (ldpl_number) " + first_value + ") == " + second_value + ".inner_collection.end()";
            }
            else if (type == "TEXT-IN-NUM-LIST")
            {
                if (rel_op == "IN")
                    condition = "find(" + second_value + ".inner_collection.begin(), " + second_value + ".inner_collection.end(), to_number(" + first_value + ")) != " + second_value + ".inner_collection.end()";
                else if (rel_op == "NOT IN")
                    condition = "find(" + second_value + ".inner_collection.begin(), " + second_value + ".inner_collection.end(), to_number(" + first_value + ")) == " + second_value + ".inner_collection.end()";
            }
            else if (type == "NUM-IN-TEXT-LIST")
            {
                if (rel_op == "IN")
                    condition = "find(" + second_value + ".inner_collection.begin(), " + second_value + ".inner_collection.end(), to_ldpl_string(" + first_value + ")) != " + second_value + ".inner_collection.end()";
                else if (rel_op == "NOT IN")
                    condition = "find(" + second_value + ".inner_collection.begin(), " + second_value + ".inner_collection.end(), to_ldpl_string(" + first_value + ")) == " + second_value + ".inner_collection.end()";
            }
            else if (type == "TEXT-IN-TEXT-LIST")
            {
                if (rel_op == "IN")
                    condition = "find(" + second_value + ".inner_collection.begin(), " + second_value + ".inner_collection.end(), " + first_value + ") != " + second_value + ".inner_collection.end()";
                else if (rel_op == "NOT IN")
                    condition = "find(" + second_value + ".inner_collection.begin(), " + second_value + ".inner_collection.end(), " + first_value + ") == " + second_value + ".inner_collection.end()";
            }
            else if (type == "NUM-IN-MAP")
            {
                if (rel_op == "IN")
                    condition = second_value + ".inner_collection.find(to_ldpl_string(" + first_value + ").str_rep()) != " + second_value + ".inner_collection.end()";
                else if (rel_op == "NOT IN")
                    condition = second_value + ".inner_collection.find(to_ldpl_string(" + first_value + ").str_rep()) == " + second_value + ".inner_collection.end()";
            }
            else if (type == "STR-IN-MAP")
            {
                if (rel_op == "IN")
                    condition = second_value + ".inner_collection.find(" + first_value + ") != " + second_value + ".inner_collection.end()";
                else if (rel_op == "NOT IN")
                    condition = second_value + ".inner_collection.find(" + first_value + ") == " + second_value + ".inner_collection.end()";
            }
            else if (type == "TEXTVAR-IN-MAP")
            {
                if (rel_op == "IN")
                    condition = second_value + ".inner_collection.find(" + first_value + ".str_rep()) != " + second_value + ".inner_collection.end()";
                else if (rel_op == "NOT IN")
                    condition = second_value + ".inner_collection.find(" + first_value + ".str_rep()) == " + second_value + ".inner_collection.end()";
            }
            else
                return "[ERROR]";
        }

        if (ct < tokens.size() && (tokens[ct] == "AND" || tokens[ct] == "OR"))
        {
            if (tokens[ct] == "AND")
                condition += " && ";
            else if (tokens[ct] == "OR")
                condition += " || ";
            ++ct;
            string next_condition = get_c_condition(state, tokens, ct);
            if (next_condition == "[ERROR]")
                return next_condition;
            condition += next_condition;
        }
    }
    return condition;
}