// Author:        Robert Rusecki
// Company:       Kolmisoft
// Year:          2020
// About:         Script cache effective from of rates


#define SCRIPT_VERSION     "1.3"
#define SCRIPT_NAME        "m2_rates_effective_from_cache"

#define error_checker(n) _error_checker(n, __func__)
#define NO_PROCESS_LOCK 1

#include "m2_functions.c"
#include "m2_rates_effective_from_cache.h"

struct tm *current_time;
char date_str[20] = "";
int tariff_id = 0;
char *effective_from;
tariff_t *tariff_head;
char *prefix;
int by_prefix = 0;
int by_date = 0;
int by_range = 0;
char *range_start;
char *range_end;

int main(int argc, char *argv[]) {
    // starting sript
    m2_init("Starting rates effective from cache script\n");

    set_current_time();

    get_arguments_values(argc, argv);

    update_cache();

    m2_log("Script completed\n");
    return 0;
}


/*
    Get arguments from command line
*/


int get_arguments_values(int argc, char *argv[]) {
    check_arguments(argc, argv);

    if (strcmp(argv[1], "-d") == 0) {
        tariff_head = initialize_tariff(-1);
        effective_from = argv[2];
        by_date = 1;

        m2_log("Rates will be updated by effective_from: %s\n", effective_from);
    } else if (strcmp(argv[1], "-t") == 0) {
        tariff_id = atoi(argv[2]);
        tariff_head = initialize_tariff(tariff_id);

        m2_log("Rates will be updated by tariff ID: %d\n", tariff_id);
    } else if (strcmp(argv[1], "-a") == 0) {
        m2_log("All Rates will be updated\n");

        tariff_head = initialize_tariff(-1);
        m2_log("Getting Tariffs \n");
        get_tariffs();
    } else if (strcmp(argv[1], "-pt") == 0) {
        tariff_id = atoi(argv[3]);
        prefix = argv[2];
        by_prefix = 1;
        tariff_head = initialize_tariff(tariff_id);

        m2_log("Rates will be updated by prefix: %s and tariff ID: %d\n", prefix, tariff_id);
    } else if (strcmp(argv[1], "-r") == 0) {
        range_start = argv[2];
        range_end = argv[3];
        by_range = 1;
        tariff_head = initialize_tariff(-1);

        m2_log("Rates will be updated in effective_from range: %s - %s\n", range_start, range_end);
    } else if (strcmp(argv[1], "-c") == 0) {
        int not_updated_count = check_effective_from(argv[2], argv[3]);
        if (not_updated_count > 0) {
            m2_log("All Rates will be updated\n");

            tariff_head = initialize_tariff(-1);
            m2_log("Getting Tariffs \n");
            get_tariffs();
        } else {
            m2_log("Rates effectiveness cache are correct");
            exit(0);
        }
    } else {
        m2_log("Bad argument");
        exit(1);
    }

    return error_checker(0);
}


/*
    Update cache
*/


int update_cache() {
    m2_log("Updating Cache \n");

    if (by_date) {
        get_active_rates_by_date(effective_from);
        update_tariffs_by_date();
    } else if (by_range) {
        get_active_rates_by_range();
        update_tariffs_by_date();
    } else {
        update_currently_effective_to_zero();
        update_rates_by_tariff();
    }

    return error_checker(0);
}


int update_rates_by_tariff() {
    tariff_t *current_tariff = tariff_head;

    while(current_tariff != NULL && current_tariff->id != -1) {
        m2_log("UPDATING Tariff: %d \n", current_tariff->id);
        m2_log("Getting effective rates \n");
        get_current_effective_rates_by_tariff(current_tariff);

        m2_log("Updating Tariff %d rates \n", current_tariff->id);
        update_current_effective_rates(current_tariff);
        m2_log("UPDATE of Tariff %d completed!\n", current_tariff->id);
        current_tariff = current_tariff->next;
    }

    return error_checker(0);
}


int update_tariffs_by_date() {
    tariff_t *current_tariff = tariff_head;

    m2_dbg_2("tariff_head -> id: %d\n", tariff_head->id);

    while(current_tariff != NULL && current_tariff->id != -1) {
        m2_log("UPDATING Tariff: %d \n", current_tariff->id);
        m2_log("Updating expired rates \n");
        update_expired_rates(current_tariff);

        m2_log("Updating Tariff %d rates \n", current_tariff->id);
        update_current_effective_rates(current_tariff);
        m2_log("UPDATE of Tariff %d completed!\n", current_tariff->id);
        current_tariff = current_tariff->next;
    }

    return error_checker(0);
}


int update_expired_rates(tariff_t *tariff) {
    char *where_sql = (char*) malloc(sizeof(char));
    rate_t *current_rate = tariff->rate;
    int n = 0;
    int total_count = 0;

    while (current_rate->next != NULL && current_rate->active == 1) {
        int digits = strlen(current_rate->prefix);
        int realloc_size = strlen(where_sql) + digits + 6;

        where_sql = (char *) realloc(where_sql, realloc_size);

        if (n == 0) {
            memset(where_sql, 0, realloc_size);
            sprintf(where_sql, "'%s'", current_rate->prefix);
        } else {
            char buffer[100] = "";
            sprintf(buffer, "'%s'", current_rate->prefix);
            strcat(where_sql, ", ");
            strcat(where_sql, buffer);
        }
        n++;
        total_count++;

        if (n == UPDATE_BATCH_SIZE) {
            m2_dbg_1("UPDATING prefixes count: %d\n", n);
            update_batch_of_prefix(tariff->id, where_sql);
            free(where_sql);
            where_sql = NULL;
            where_sql = (char*) malloc(sizeof(char));
            memset(where_sql, 0, sizeof(char));

            m2_dbg_1("UPDATED Prefixes\n");
            m2_dbg_1("Total updated prefixes: %d\n", total_count);
            n = 0;
        }
        current_rate = current_rate->next;
    }

    if (n > 0) {
        m2_dbg_1("UPDATING prefixes count: %d\n", n);
        update_batch_of_prefix(tariff->id, where_sql);
        free(where_sql);
    }

    return error_checker(0);
}


int update_batch_of_prefix(int id, char *prefixes) {
    char *query;
    char where[64] = "";
    query = (char*) malloc(512 +  strlen(prefixes));

    if (by_date) {
        sprintf(where, "AND effective_from != '%s'", effective_from);
    }

    sprintf(query, "UPDATE rates SET currently_effective = 0 WHERE tariff_id = %d AND prefix IN (%s) %s", id, prefixes, where);

    if (m2_mysql_query(query)) {
        return error_checker(-1);
    }

    free(query);
    query = NULL;

    return error_checker(0);
}

int get_active_rates_by_range() {
    MYSQL_RES *result;
    MYSQL_ROW row;
    char query[1024] = "";
    tariff_t *current_tariff = tariff_head;
    rate_t *current_rate = NULL;
    int tariff_id = 0;
    int first_tariff = 1;
    char prev_prefix[16] = "";
    int prev_tariff_id = 0;
    char currently_effective_prefix[16] = "";

    sprintf(query, "SELECT rates.id, "
                    "rates.currently_effective, rates.tariff_id, rates.prefix "
                    "FROM rates WHERE (effective_from BETWEEN '%s' AND '%s') "
                    "ORDER BY rates.tariff_id, rates.prefix, rates.effective_from DESC", range_start, range_end);



    if (m2_mysql_query(query)) {
        return error_checker(-1);
    }

    result = mysql_store_result(&mysql);

    if (result) {
        while((row = mysql_fetch_row(result))) {
            m2_log("rate_id: %lld\n", atoll(row[0]));
            tariff_id = atoi(row[2]);
            int currently_effective = atoi(row[1]);

            if (currently_effective == 1 || (strcmp(currently_effective_prefix, row[3]) == 0 && tariff_id == prev_tariff_id)){
                strcpy(currently_effective_prefix, row[3]);
                prev_tariff_id = tariff_id;
                continue;
            }

            if (current_tariff->id != tariff_id) {
                if (first_tariff == 0)
                    current_tariff = current_tariff->next;
                first_tariff = 0;
                strcpy(prev_prefix, "");

                current_tariff->id = tariff_id;
                current_tariff->next = initialize_tariff(-1);
                current_tariff->rate = initialize_rate(0);
                current_rate = current_tariff->rate;
                prev_tariff_id = tariff_id;
            }
            char current_prefix[16] = "";
            if (row[3]) {
                strcpy(current_prefix, row[3]);
            } else {
                continue;
            }

            if (strcmp(prev_prefix, current_prefix) == 0)
                continue;
            strcpy(prev_prefix, current_prefix);

            current_rate->id = atoll(row[0]);
            m2_dbg_1("save_id: %lld\n", current_rate->id);
            current_rate->active = 1;
            strcpy(current_rate->prefix, current_prefix);

            current_rate->next = initialize_rate(0);
            current_rate = current_rate->next;
        }
    }

    return error_checker(0);

}


int get_active_rates_by_date(char *date) {
    MYSQL_RES *result;
    MYSQL_ROW row;
    char query[1024] = "";
    tariff_t *current_tariff = tariff_head;
    int tariff_id = 0;
    rate_t *current_rate = NULL;
    int first_tariff = 1;

    sprintf(query, "SELECT id, tariff_id, prefix FROM rates WHERE effective_from = '%s' ORDER BY tariff_id", date);


    if (m2_mysql_query(query)) {
        return error_checker(-1);
    }

    result = mysql_store_result(&mysql);
    if (result) {
        while ((row = mysql_fetch_row(result))) {

            tariff_id = atoi(row[1]);
            if (current_tariff->id != tariff_id) {

                if (first_tariff == 0) {
                    current_tariff = current_tariff->next;
                }

                first_tariff = 0;
                current_tariff->id = atoi(row[1]);

                current_tariff->next = initialize_tariff(-1);
                tariff_id = current_tariff->id;
                current_tariff->rate = initialize_rate(0);
                current_rate = current_tariff->rate;

                m2_dbg_2("Current Tariff ID: %d\n", current_tariff->id);
            }

            current_rate->id = atoll(row[0]);
            current_rate->active = 1;
            if (row[2]) strcpy(current_rate->prefix, row[2]);

            m2_dbg_2("current_rate->id: %lld\n", current_rate->id);

            current_rate->next = initialize_rate(0);
            current_rate = current_rate->next;

        }
    }

    return error_checker(0);
}


int get_tariffs() {
    MYSQL_RES *result;
    MYSQL_ROW row;
    char query[1024] = "";
    tariff_t *current_tariff = tariff_head;

    sprintf(query, "SELECT tariff_id FROM rates GROUP BY tariff_id");

    if (m2_mysql_query(query)) {
        return error_checker(-1);
    }

    result = mysql_store_result(&mysql);
    if (result) {
        while ((row = mysql_fetch_row(result))) {
            current_tariff->id = atoi(row[0]);
            current_tariff->next = initialize_tariff(-1);
            current_tariff = current_tariff->next;
        }
    }

    return error_checker(0);
}


int update_current_effective_rates(tariff_t *tariff) {
    char *where_sql = (char*) malloc(sizeof(char));
    rate_t *current_rate = tariff->rate;
    int n = 0;


    while (current_rate->active == 1) {
        int digits = floor(log10(abs(current_rate->id))) + 1;
        where_sql = (char *) realloc(where_sql, sizeof(char) * (strlen(where_sql) + digits + 4));

        if (n == 0) {
            sprintf(where_sql, "%lld", current_rate->id);
        } else {
            char buffer[100] = "";
            sprintf(buffer, "%lld", current_rate->id);
            strcat(where_sql, ", ");
            strcat(where_sql, buffer);
        }
        n++;

        if (n == UPDATE_BATCH_SIZE) {
            m2_dbg_1("UPDATING IDS count: %d\n", n);
            update_batch_of_ids(where_sql);
            memset(where_sql, 0, strlen(where_sql));
            free(where_sql);
            where_sql = NULL;
            where_sql = (char*) malloc(sizeof(char));
            memset(where_sql, 0, sizeof(char));

            m2_dbg_1("UPDATED IDS\n");
            n = 0;
        }
        current_rate = current_rate->next;
    }

    if (n > 0) {
        m2_dbg_1("UPDATING IDS count: %d\n", n);
        update_batch_of_ids(where_sql);
    }

    free(where_sql);

    return error_checker(0);
}


int update_batch_of_ids(char *ids) {
    char *query;
    query = (char*) malloc((strlen(ids) + 128) * sizeof(char));

    sprintf(query, "UPDATE rates SET currently_effective = 1 WHERE id IN (%s)", ids);

    if (m2_mysql_query(query)) {
        return error_checker(-1);
    }

    free(query);
    query = NULL;

    return error_checker(0);
}


int update_currently_effective_to_zero() {
    char query[1024] = "";
    char where_sql[256] = "";

    m2_log("Updating rates currently_effective to zero \n");

    if (tariff_id > 0) {
        m2_dbg_1("Updating by one tariff ID: %d\n", tariff_id);
        sprintf(where_sql, "WHERE tariff_id = %d", tariff_id);

        if (by_prefix) {
            char buffer[100] = "";
            m2_dbg_1("Updating by one prefix: %s\n", prefix);
            sprintf(buffer, " AND prefix = '%s'", prefix);
            strcat(where_sql, buffer);
        }
    }

    sprintf(query, "UPDATE rates SET currently_effective = 0 %s", where_sql);

    if (m2_mysql_query(query)) {
        return error_checker(-1);
    }

    return error_checker(0);
}


int get_current_effective_rates_by_tariff(tariff_t *tariff) {
    MYSQL_RES *result;
    MYSQL_ROW row;

    char query[1024] = "";
    char where_sql[256] = "";
    tariff->rate = initialize_rate(-1);
    rate_t *current_rate = tariff->rate;

    sprintf(where_sql, "AND tariff_id = %d", tariff->id);

    if (by_prefix) {
        char buffer[100] = "";
        sprintf(buffer, " AND prefix = '%s' ", prefix);
        strcat(where_sql, buffer);
    }

    /*
    SELECT id FROM (SELECT rates.id, rates.prefix FROM rates
            LEFT JOIN destinations on rates.destination_id = destinations.id
            WHERE (effective_from < now() OR effective_from IS NULL) AND #{condition}
            ORDER BY rates.effective_from DESC, id DESC) AS tmp_table GROUP BY prefix
    */

    sprintf(query, "SELECT id FROM (SELECT rates.id, rates.prefix FROM rates "
        "WHERE (effective_from < now() OR effective_from IS NULL) %s "
        "ORDER BY rates.effective_from DESC) AS tmp_table GROUP BY prefix", where_sql);

    m2_dbg_1("SELECT Query: %s \n", query);

    if (m2_mysql_query(query)) {
        return error_checker(-1);
    }

    result = mysql_store_result(&mysql);
    if (result) {
        while ((row = mysql_fetch_row(result))) {
            current_rate->id = atoll(row[0]);
            current_rate->active = 1;

            m2_dbg_2("current_rate->id: %lld\n", current_rate->id);

            current_rate->next = initialize_rate(0);
            current_rate = current_rate->next;
        }
    }

    //m2_log("head id : %d\n", head->id);

    return error_checker(0);
}


int check_effective_from(char *from, char *till) {
    MYSQL_RES *result;
    MYSQL_ROW row;
    char query[1024] = "";
    int not_updated_count = 0;

    sprintf(query, "SELECT COUNT(*) FROM rates "
        "WHERE effective_from BETWEEN '%s' AND '%s' AND currently_effective = 0", from, till);

    if (m2_mysql_query(query)) {
        return error_checker(-1);
    }

    result = mysql_store_result(&mysql);
    if (result) {
        if ((row = mysql_fetch_row(result))) {
            not_updated_count = atoi(row[0]);
        }
    }

    if (not_updated_count > 0) {
        return error_checker(not_updated_count);
    }


    return error_checker(0);
}



//===========================================

/*
    Helper methods
*/

int _error_checker(int return_code, char const * caller_name) {
    if (return_code < 0) {
        char query[512] = "";
        m2_log("Error in: %s\n", caller_name);

        sprintf(query, "INSERT IGNORE INTO conflines (name, value) SELECT 'rates_cache_error', 'Error in: %s'"\
            " FROM dual WHERE NOT EXISTS (SELECT * FROM conflines WHERE name = 'rates_cache_error')", caller_name);
        m2_mysql_query(query);
        exit(return_code);
    } else {
        return return_code;
    }
}

int set_current_time() {
    time_t rawtime;

    time(&rawtime);
    current_time = localtime(&rawtime);

    strftime(date_str, sizeof(date_str), DATE_FORMAT, current_time);

    m2_log("Current time and date: %s\n", date_str);

    return error_checker(0);
}

tariff_t *initialize_tariff(int id) {
    tariff_t *tariff = (tariff_t *) malloc(sizeof(tariff_t));
    tariff->id = id;
    tariff->next = NULL;
    tariff->rate = NULL;
    return tariff;
}


rate_t *initialize_rate(long long int id) {
    rate_t *rate = (rate_t *) malloc(sizeof(rate_t));
    rate->id = id;
    rate->next = NULL;
    rate->active = 0;
    return rate;
}


int check_arguments(int argc, char *argv[]) {
    if (argc < 2) {
        goto error;
    } else if (strcmp(argv[1], "-pt") == 0 && argc != 4) {
        goto error;
    } else if ((strcmp(argv[1], "-a") != 0 || strcmp(argv[1], "-c") != 0 ) && argc < 3) {
        goto error;
    } else {
        m2_dbg_1("Argument option: %s\n", argv[1]);
    }

    return error_checker(0);
error:
    m2_log("Use it with options: -d; -t; -a; -pt");
    exit(1);
}