#include <stdio.h>
#include "syslog.h"
#include "rpc/rpc_server.h"
#include "io/io_base.h"
#include "io/io_gsm.h"
#include "utils.h"
#include "fatfs/ff.h"

// Run an AT command, log failures
static bool AT_command(const char *command)
{
    char buffer[80];
    fputs(command, FILE_GSM);
    
    syslog("at command '%20s'", (unsigned)command, 0);
    
    for (;;) {
        if (!fgets(buffer, 80, FILE_GSM))
        {
            // Passing the string might fail if it is not a ROM constant,
            // but even in that case %20s avoids crash and causes just
            // garbage to be printed.
            syslog("at command '%20s' reply timeout", (unsigned)command, 0);
            return false;
        }
    
        if (strncmp(buffer, "OK", 2) == 0)
            return true;
        
        if (strncmp(buffer, "ERROR", 5) == 0)
        {
            syslog("at command '%20s' error", (unsigned)command, 0);
            return false;
        }
    }
}

static bool HTTP_command(const char *command)
{
    char buffer[80];
    while (fread2(buffer, sizeof(buffer), FILE_GSM, 5)); // Flush buffers
    fputs(command, FILE_GSM);
    
    bool status_ok = false;
    do {
        if (!fgets(buffer, 80, FILE_GSM))
        {
            syslog("http command '%20s' reply timeout", (unsigned)command, 0);
            return false;
        }
        
        if (strstr(buffer, " 200 ") != NULL)
            status_ok = true;
    } while (strcspn(buffer, "\r\n") != 0); // Empty line terminates HTTP reply
    
    return status_ok;
}

/* GPRS connection */
void GSM_task( void *pvParameters )
{
    FIL file;
    f_open(&file, "/diallog", FA_WRITE | FA_OPEN_ALWAYS);
    f_lseek(&file, f_size(&file));
    insert_io_clone(FILE_GSM, (FILE*)&file);
    
    for(;;)
    {
        fwrite("S\n", 2, 1, (FILE*)&file);
        f_sync(&file);
        
        // Turn on the GSM module
        if (!io_gsm_poweron())
        {
            syslog("io_gsm_poweron failed", 0, 0);
            continue;
        }
        
        // Dial up
        // Ignore errors, the modem may be already on.
        AT_command("ATE0\r\n");
        AT_command("AT+CPIN=\"8502\"\r\n");
        AT_command("AT+COPS=0\r\n");
        
        if (!(AT_command("AT+CGDCONT=1,\"IP\",\"wap\"\r\n") &&
              AT_command("AT$DESTINFO=\"10.1.1.1\",1,8080\r\n") &&
              AT_command("ATD*97#\r\n")))
        {
            syslog("GPRS dialup failed", 0, 0);
            continue;
        }
        
        // Connect to server through HTTP proxy
        if (!HTTP_command("CONNECT lakka.kapsi.fi:50140 HTTP/1.1\r\n"
                          "Host: lakka.kapsi.fi:50140\r\n\r\n"))
        {
            syslog("HTTP connect failed", 0, 0);
            continue;
        }
        
        remove_io_clone(FILE_GSM, (FILE*)&file);
        rpc_chat(FILE_GSM);
    }
}