#include "../include/StringUtils.hpp"
#include <string.h>
#include <fcntl.h>
#include <unistd.h>

namespace QuickMedia {
    template <typename T>
    static void string_split_t(const std::string_view str, const T &delimiter, StringSplitCallback callback_func, bool include_empty) {
        size_t index = 0;
        while(index < str.size()) {
            size_t new_index = str.find(delimiter, index);
            if(new_index == std::string::npos)
                new_index = str.size();

            if(include_empty || new_index - index > 0) {
                if(!callback_func(str.data() + index, new_index - index))
                    break;
            }

            if constexpr(std::is_same<char, T>::value)
                index = new_index + 1;
            else
                index = new_index + delimiter.size();
        }
    }

    void string_split(const std::string &str, const std::string &delimiter, StringSplitCallback callback_func, bool include_empty) {
        string_split_t(std::string_view(str), delimiter, callback_func, include_empty);
    }

    void string_split(const std::string &str, char delimiter, StringSplitCallback callback_func, bool include_empty) {
        string_split_t(std::string_view(str), delimiter, callback_func, include_empty);
    }

    void string_split_view(const std::string_view str, const std::string &delimiter, StringSplitCallback callback_func, bool include_empty) {
        string_split_t(str, delimiter, callback_func, include_empty);
    }

    void string_split_view(const std::string_view str, char delimiter, StringSplitCallback callback_func, bool include_empty) {
        string_split_t(str, delimiter, callback_func, include_empty);
    }

    size_t string_replace_all(std::string &str, char old_char, char new_char) {
        size_t num_replaced_substrings = 0;
        for(char &c : str) {
            if(c == old_char) {
                c = new_char;
                ++num_replaced_substrings;
            }
        }
        return num_replaced_substrings;
    }

    size_t string_replace_all(std::string &str, char old_char, const std::string &new_str) {
        size_t num_replaced_substrings = 0;
        size_t index = 0;
        while(index < str.size()) {
            index = str.find(old_char, index);
            if(index == std::string::npos)
                break;
            str.replace(index, 1, new_str);
            index += new_str.size();
            ++num_replaced_substrings;
        }
        return num_replaced_substrings;
    }

    size_t string_replace_all(std::string &str, const std::string &old_str, const std::string &new_str) {
        size_t num_replaced_substrings = 0;
        size_t index = 0;
        while(index < str.size()) {
            index = str.find(old_str, index);
            if(index == std::string::npos)
                break;
            str.replace(index, old_str.size(), new_str);
            index += new_str.size();
            ++num_replaced_substrings;
        }
        return num_replaced_substrings;
    }

    static bool is_whitespace(char c) {
        return c == ' ' || c == '\n' || c == '\t' || c == '\v';
    }

    std::string strip(const std::string &str) {
        if(str.empty())
            return str;

        int start = 0;
        for(; start < (int)str.size(); ++start) {
            if(!is_whitespace(str[start]))
                break;
        }

        int end = str.size() - 1;
        for(; end >= start; --end) {
            if(!is_whitespace(str[end]))
                break;
        }

        return str.substr(start, end - start + 1);
    }

    void strip(const char *str, size_t size, size_t *new_size) {
        if(size == 0) {
            *new_size = 0;
            return;
        }

        int start = 0;
        for(; start < (int)size; ++start) {
            if(!is_whitespace(str[start]))
                break;
        }

        int end = (int)size - 1;
        for(; end >= start; --end) {
            if(!is_whitespace(str[end]))
                break;
        }

        *new_size = end - start + 1;
    }

    bool string_starts_with(const std::string &str, const char *sub) {
        size_t sub_len = strlen(sub);
        return sub_len == 0 || (str.size() >= sub_len && memcmp(str.c_str(), sub, sub_len) == 0);
    }

    bool string_ends_with(const std::string &str, const std::string &ends_with_str) {
        size_t ends_len = ends_with_str.size();
        return ends_len == 0 || (str.size() >= ends_len && memcmp(&str[str.size() - ends_len], ends_with_str.data(), ends_len) == 0);
    }

    size_t str_find_case_insensitive(const std::string &str, size_t start_index, const char *substr, size_t substr_len) {
        if(substr_len == 0)
            return 0;

        auto it = std::search(str.begin() + start_index, str.end(), substr, substr + substr_len,
            [](char c1, char c2) {
                return to_upper(c1) == to_upper(c2);
            });

        if(it == str.end())
            return std::string::npos;

        return it - str.begin();
    }

    // TODO: Support utf-8 case insensitive find
    bool string_find_fuzzy_case_insensitive(const std::string &str, const std::string &substr) {
        if(substr.empty()) return true;
        if(str.empty()) return false;

        size_t str_index = 0;
        bool full_match = true;

        string_split(substr, ' ', [&str, &str_index, &full_match](const char *str_part, size_t size) {
            if(size == 0) return true;

            size_t found_index = str_find_case_insensitive(str, str_index, str_part, size);
            if(found_index == std::string::npos) {
                full_match = false;
                return false;
            }

            str_index = found_index + size;
            return true;
        });

        return full_match;
    }

    char to_upper(char c) {
        if(c >= 'a' && c <= 'z')
            return c - 32;
        else
            return c;
    }

    bool strncase_equals(const char *str1, const char *str2, size_t length) {
        size_t i = 0;
        for(;;) {
            if(i == length)
                return true;
            ++i;

            const char c1 = *str1;
            const char c2 = *str2;
            if(to_upper(c1) != to_upper(c2))
                return false;
            else if(c1 == '\0')
                return true;

            ++str1;
            ++str2;
        }
    }

    bool strcase_equals(const char *str1, const char *str2) {
        for(;;) {
            const char c1 = *str1;
            const char c2 = *str2;

            if(to_upper(c1) != to_upper(c2))
                return false;
            else if(c1 == '\0')
                return true;

            ++str1;
            ++str2;
        }
    }

    bool to_num(const char *str, size_t size, int64_t &num) {
        if(size == 0)
            return false;

        size_t i = 0;
        const bool is_negative = size > 0 && str[0] == '-';
        if(is_negative)
            i = 1;

        num = 0;
        for(; i < size; ++i) {
            const char num_c = str[i] - '0';
            if(num_c < 0 || num_c > 9)
                return false;
            num = (num * 10) + num_c;
        }

        if(is_negative)
            num = -num;

        return true;
    }

    bool to_num(const char *str, size_t size, int &num) {
        int64_t num_i64 = 0;
        const bool res = to_num(str, size, num_i64);
        num = num_i64;
        return res;
    }

    bool to_num_hex(const char *str, size_t size, int &num) {
        if(size == 0)
            return false;

        size_t i = 0;
        const bool is_negative = size > 0 && str[0] == '-';
        if(is_negative)
            i = 1;

        num = 0;
        for(; i < size; ++i) {
            const signed char c = str[i];
            if(c - '0' <= 9)
                num = (num << 4) | (c - '0');
            else if(c - 'a' <= 'f' - 'a')
                num = (num << 4) | (10 + (c - 'a'));
            else if(c - 'A' <= 'F' - 'A')
                num = (num << 4) | (10 + (c - 'A'));
            else
                return false;
        }

        if(is_negative)
            num = -num;

        return true;
    }

    // Returns relative time as a string (approximation)
    std::string seconds_to_relative_time_str(time_t seconds) {
        seconds = std::max(0L, seconds);

        time_t minutes = seconds / 60;
        time_t hours = minutes / 60;
        time_t days = hours / 24;
        time_t months = days / 30;
        time_t years = days / 365;

        if(years >= 1)
            return std::to_string(years) + " year" + (years == 1 ? "" : "s") + " ago";
        else if(months >= 1)
            return std::to_string(months) + " month" + (months == 1 ? "" : "s") + " ago";
        else if(days >= 1)
            return std::to_string(days) + " day" + (days == 1 ? "" : "s") + " ago";
        else if(hours >= 1)
            return std::to_string(hours) + " hour" + (hours == 1 ? "" : "s") + " ago";
        else if(minutes >= 1)
            return std::to_string(minutes) + " minute" + (minutes == 1 ? "" : "s") + " ago";
        else
            return std::to_string(seconds) + " second" + (seconds == 1 ? "" : "s") + " ago";
    }

    std::string seconds_to_duration(int seconds) {
        seconds = std::max(0, seconds);

        int minutes = seconds / 60;
        int hours = minutes / 60;
        char buffer[32];

        if(hours >= 1) {
            minutes -= (hours * 60);
            seconds -= (hours * 60 * 60);
            seconds -= (minutes * 60);
            snprintf(buffer, sizeof(buffer), "%02d:%02d:%02d", hours, minutes, seconds);
        } else if(minutes >= 1) {
            seconds -= (minutes * 60);
            snprintf(buffer, sizeof(buffer), "%02d:%02d", minutes, seconds);
        } else {
            snprintf(buffer, sizeof(buffer), "00:%02d", seconds);
        }

        return buffer;
    }

    std::string number_separate_thousand_commas(const std::string &number) {
        const int num_commas = ((int)number.size() - 1) / 3;
        std::string result;
        result.resize(number.size() + num_commas);
        int result_index = (int)number.size() + num_commas - 1;
        int inc = 0;

        for(int i = (int)number.size() - 1; i >= 0; --i, ++inc) {
            if(inc > 0 && inc % 3 == 0) {
                result[result_index] = ',';
                --result_index;
            }

            result[result_index] = number[i];
            --result_index;
        }

        return result;
    }

    bool generate_random_characters(char *buffer, int buffer_size, const char *alphabet, size_t alphabet_size) {
        if(alphabet_size == 0)
            return false;

        int fd = open("/dev/urandom", O_RDONLY);
        if(fd == -1) {
            perror("/dev/urandom");
            return false;
        }

        if(read(fd, buffer, buffer_size) < buffer_size) {
            fprintf(stderr, "Failed to read %d bytes from /dev/urandom\n", buffer_size);
            close(fd);
            return false;
        }

        for(int i = 0; i < buffer_size; ++i) {
            unsigned char c = *(unsigned char*)&buffer[i];
            buffer[i] = alphabet[c % alphabet_size];
        }

        close(fd);
        return true;
    }
}