#include <iterator>
#include <sstream>
#include <unordered_set>
#include <unordered_map>
#include <functional>
#include <algorithm>
#include <cctype>

#include "solutions.hpp"

using namespace std;

bool is_digit(char c) {
    return isdigit((int) c);
}

bool is_hex_digit(char c) {
    return isdigit((int) c) || (c >= 'a' && c <= 'f');
}

template <>
pair<string, string> solve<4>(istream& input) {
    cerr << boolalpha;
    stringstream current_passport{string()};
    uint64_t part1 = 0, part2 = 0;
    unordered_map<string, function<bool(string&)>> valid_funcs;
    valid_funcs["byr"] = [](string &value) {
        int int_value = stoi(value);
        return value.length() == 4 && all_of(value.begin(), value.end(), is_digit) && int_value >= 1920 && int_value <= 2002;
    };
    valid_funcs["iyr"] = [](string &value) {
        int int_value = stoi(value);
        return value.length() == 4 && all_of(value.begin(), value.end(), is_digit) && int_value >= 2010 && int_value <= 2020;
    };
    valid_funcs["eyr"] = [](string &value) {
        int int_value = stoi(value);
        return value.length() == 4 && all_of(value.begin(), value.end(), is_digit) && int_value >= 2020 && int_value <= 2030;
    };
    valid_funcs["hgt"] = [](string &value) {
        int int_value = stoi(value);
        return (value.length() == to_string(int_value).length() + 2) && (
                (value.ends_with("in") && int_value >= 59 && int_value <= 76) ||
                (value.ends_with("cm") && int_value >= 150 && int_value <= 193)
                );
    };
    valid_funcs["hcl"] = [](string &value) {
        auto it = value.begin();
        return value.length() == 7 && *it == '#' && all_of(next(it), value.end(), is_hex_digit);
    };
    valid_funcs["ecl"] = [](string &value) {
        unordered_set<string> valid_eye_colors = { {
            "amb"s, "blu"s, "brn"s, "gry"s, "grn"s, "hzl"s, "oth"s
        } };
        return valid_eye_colors.contains(value);
    };
    valid_funcs["pid"] = [](string &value) {
        return value.length() == 9 && all_of(value.begin(), value.end(), is_digit);
    };

    for (string line; getline(input, line); ) {
        if (!line.empty()) { // append to existing passport
            if (!current_passport.eof()) {
                current_passport << ' ';
            }
            current_passport << line;
        }
        if (line.empty() || input.peek() == EOF) { // no input; parse current passport
            unordered_set<string> mandatory_fields = {
                { "byr"s, "iyr"s, "eyr"s, "hgt"s, "hcl"s, "ecl"s, "pid"s}
            };
            bool all_fields_valid = true;
            for (string entry; getline(current_passport, entry, ' '); ) {
                auto field_delim_pos = entry.find(':');
                if (field_delim_pos != string::npos) {
                    string field_name = entry.substr(0, field_delim_pos);
                    string field_value = entry.substr(field_delim_pos+1);
                    mandatory_fields.erase(field_name);
                    if (valid_funcs.contains(field_name)) {
                        all_fields_valid = all_fields_valid && valid_funcs[field_name](field_value);
                    }
                }
            }
            current_passport.clear();
            part1 += (uint64_t) mandatory_fields.empty();
            part2 += (uint64_t) (mandatory_fields.empty() && all_fields_valid);
        }
    }
    return pair(to_string(part1), to_string(part2));
}