// Author:        Ricardas Stoma
// Company:       Kolmisoft
// Year:          2018
// About:         Script deletes old calls from 'calls' table

#define SCRIPT_VERSION      "1.3"
#define SCRIPT_NAME         "m2_delete_old_calls"
#define SQL_LIMIT           1000
#define BATCH_SIZE          250
#define IDS_BUFFER_SIZE     BATCH_SIZE * 20 + 256

#include "m2_functions.c"

// VARIABLES

// SQL variables
char sql_delete_statement[64] = "DELETE FROM calls WHERE id IN (";
char sql_count_statement[64] = "SELECT COUNT(id) FROM calls WHERE id IN (";
char buffer[4096] = "";
long long int total_calls = 0;

// call ids stored in array for future deletion
char ids_buffer[IDS_BUFFER_SIZE] = "";
char check_ids_buffer[IDS_BUFFER_SIZE] = "";
long long int ids[SQL_LIMIT];

int older_than = 0;

char min_calldate[20] = "";
char max_calldate[20] = "";

// FUNCTION DECLARATIONS

int delete_calls_from_database(int calls);
int delete_not_answered_calls();
void get_settings_from_conflines();
void get_calls_count();

// MAIN FUNCTION

int main(int argc, char *argv[]) {

    // starting the script
    m2_init("Starting M2 Delete Old Calls script\n");

    get_elasticsearch_host();

    // get various settings
    get_settings_from_conflines();

    // delete not answered calls
    if (older_than > 0) {
        m2_log("Deleting not answered calls older than %d days\n", older_than)
        get_calls_count();
        if (total_calls > 0) {
            m2_log("%lld calls will be deleted\n", total_calls);
            delete_not_answered_calls();

            m2_log("Oldest calldate: %s\n", min_calldate);
            m2_log("Latest calldate: %s\n", max_calldate);

            if (strlen(min_calldate) && strlen(max_calldate)) {
                char system_cmd[256] = "";
                m2_system_cmd_response_t response;
                m2_log("Resyncing elasticsearch for period %s - %s\n", min_calldate, max_calldate);
                sprintf(system_cmd, "/usr/bin/elasticsearch resync interval '%s' '%s'", min_calldate, max_calldate);
                m2_execute_system_command(system_cmd, &response);
                m2_log("Status: [%d], response: [%s], error: [%s]\n", response.return_code, response.data, response.error);
            }
        } else {
            m2_log("Nothing to delete\n");
        }
    } else {
        m2_log("Calls should not be deleted from database (setting value is 0)\n")
    }

    m2_log("Script finished\n");

    return 0;
}

int delete_calls_from_database(int calls) {

    MYSQL_RES *result;
    MYSQL_ROW row;

    int i = 0;
    int batch_counter = 0;

    // initialize ids_buffer
    strcpy(ids_buffer, sql_delete_statement);
    strcpy(check_ids_buffer, sql_count_statement);
    long long int check_calls = 0;
    int last_iteration_done = 0;

    // delete from calls table
    for (i = 0; i < calls; i++) {

        sprintf(buffer, "%lld,", ids[i]);
        strcat(ids_buffer, buffer);
        strcat(check_ids_buffer, buffer);

        batch_counter++;

        // batch is full, send query
        if (batch_counter == BATCH_SIZE) {

            last_iteration:

            ids_buffer[strlen(ids_buffer) - 1] = 0;
            check_ids_buffer[strlen(check_ids_buffer) - 1] = 0;
            strcat(ids_buffer, ");");
            strcat(check_ids_buffer, ");");

            // delete from MySQL
            if (m2_mysql_query(ids_buffer)) {
                return 1;
            }

            // check if calls with those ids are delete
            if (m2_mysql_query(check_ids_buffer)) {
                return 1;
            }

            check_calls = -1;

            result = mysql_store_result(&mysql);
            if (result) {
                if (mysql_num_rows(result)) {
                    row = mysql_fetch_row(result);
                    if (row[0]) check_calls = atoll(row[0]);
                }
            }

            mysql_free_result(result);

            if (check_calls == -1) {
                m2_log("Can't determine if calls where deleted correctly\n");
                m2_log("%s\n", check_ids_buffer);
                return 1;
            } else if (check_calls) {
                m2_log("Tried to delete %d calls, but there are still %lld calls left. Check why some calls where not deleted!\n", BATCH_SIZE, check_calls);
                m2_log("%s\n", check_ids_buffer);
                return 1;
            }

            *ids_buffer = 0;
            *check_ids_buffer = 0;
            strcpy(ids_buffer, sql_delete_statement);
            strcpy(check_ids_buffer, sql_count_statement);
            batch_counter = 0;

            if (last_iteration_done) break;

        }
    }

    // if batch is not full, send query anyway
    if (strlen(ids_buffer) > strlen(sql_delete_statement) && last_iteration_done == 0) {
        last_iteration_done = 1;
        goto last_iteration;
    }

    return 0;
}


/*
    Delete not answered calls from calls table (older than x days)
*/


int delete_not_answered_calls() {

    MYSQL_RES *result;
    MYSQL_ROW row;
    char query[2048] = "";
    int done = 0;
    int counter = 0;

    strcpy(sql_delete_statement, "DELETE FROM calls WHERE id IN (");
    sprintf(sql_count_statement, "SELECT COUNT(id) FROM calls WHERE id IN (");

    sprintf(query, "SELECT id, calldate FROM calls WHERE disposition != 'ANSWERED' AND calldate < DATE_SUB(DATE_FORMAT(NOW(), '%%Y-%%m-%%d %%H:30:00'), INTERVAL %d DAY) ORDER BY calldate LIMIT %d", older_than, SQL_LIMIT);

    while (done == 0) {

        int records = 0;
        done = 1;

        memset(ids_buffer, 0, sizeof(ids_buffer));
        memset(check_ids_buffer, 0, sizeof(check_ids_buffer));

        // get calls count
        if (m2_mysql_query(query)) {
            exit(1);
        }

        result = mysql_store_result(&mysql);

        // fetch data
        while ((row = mysql_fetch_row(result)) != NULL) {
            if (row[0]) {
                ids[records] = atoll(row[0]);
                records++;
                done = 0;

                // get oldest calldate and latest calldates
                if (row[1]) {
                    if (!strlen(min_calldate)) strcpy(min_calldate, row[1]);
                    strcpy(max_calldate, row[1]);
                }
            }
        }

        mysql_free_result(result);

        if (delete_calls_from_database(records)) return 1;

        counter++;
        if (counter >= 10000) {
            m2_log("Possible loop detected. Breaking out of it!\n");
            return 0;
        }

    }

    return 0;

}


/*
    Get various settings from conflines
*/


void get_settings_from_conflines() {

    MYSQL_RES *result;
    MYSQL_ROW row;

    m2_log("Reading conflines\n");

    // get Delete_not_Archived_not_Answered_Calls_older_than value
    if (m2_mysql_query("SELECT value FROM conflines WHERE name = 'Delete_not_Archived_not_Answered_Calls_older_than'")) {
        exit(1);
    }

    result = mysql_store_result(&mysql);
    if (result) {
        if (mysql_num_rows(result)) {
            row = mysql_fetch_row(result);
            // check if we get result
            if (row[0]) {
                older_than = atoi(row[0]);
            }
        }
    }

    mysql_free_result(result);

}


/*
    Check how many calls need to be deleted
*/


void get_calls_count() {

    MYSQL_RES *result;
    MYSQL_ROW row;

    char query[1024] = "";

    sprintf(query, "SELECT COUNT(*) FROM calls WHERE disposition != 'ANSWERED' AND calldate < DATE_SUB(DATE_FORMAT(NOW(), '%%Y-%%m-%%d %%H:30:00'), INTERVAL %d DAY)", older_than);

    if (m2_mysql_query(query)) {
        exit(1);
    }

    result = mysql_store_result(&mysql);

    while ((row = mysql_fetch_row(result)) != NULL) {
        if (row[0]) {
            total_calls = atoi(row[0]);
        }
    }

    mysql_free_result(result);

}