/*
    Copyright (C) 2014 CSP Innovazione nelle ICT s.c.a r.l. (http://www.csp.it/)
    Copyright (C) 2016 Matthias P. Braendli (http://www.opendigitalradio.org)
    Copyright (C) 2015 Data Path

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.

    Authors:
         Sergio Sagliocco <sergio.sagliocco@csp.it>
         Matthias P. Braendli <matthias@mpb.li>
                   / |  |-  ')|)  |-|_ _ (|,_   .|  _  ,_ \
         Data Path \(|(||_(|/_| (||_||(a)_||||(|||.(_()|||/

*/

#include "figs.hpp"
#include <cstdio>
#include <cstring>
#include <map>
#include <unordered_set>

static std::unordered_set<int> regions_seen;

bool fig0_21_is_complete(int region_id)
{
    bool complete = regions_seen.count(region_id);

    if (complete) {
        regions_seen.clear();
    }
    else {
        regions_seen.insert(region_id);
    }

    return complete;
}


// FIG 0/21 Frequency Information
// ETSI EN 300 401 8.1.8
bool fig0_21(fig0_common_t& fig0, const display_settings_t &disp)
{
    float freq;
    uint32_t ifreq;
    uint64_t key;
    uint16_t RegionId, Id_field;
    uint8_t i = 1, j, k, Length_FI_list, RandM, Length_Freq_list, Control_field;
    uint8_t Control_field_trans_mode, Id_field2;
    char tmpbuf[256];
    char desc[256];
    bool Continuity_flag;
    uint8_t* f = fig0.f;
    bool complete = false;

    while (i < (fig0.figlen - 1)) {
        // iterate over frequency information
        // decode RegionId, Length of FI list
        RegionId  =  (f[i] << 3) | (f[i+1] >> 5);
        complete |= fig0_21_is_complete(RegionId);
        Length_FI_list  = (f[i+1] & 0x1F);
        sprintf(desc, "RegionId=0x%03x", RegionId);
        printbuf(desc, disp+1, NULL, 0);
        i += 2;
        if ((i + Length_FI_list) <= fig0.figlen) {
            j = i;
            while ((j + 2) < (i + Length_FI_list)) {
                // iterate over FI list x
                // decode Id field, R&M, Continuity flag, Length of Freq list
                Id_field = (f[j] << 8) | f[j+1];
                RandM = f[j+2] >> 4;
                Continuity_flag = (f[j+2] >> 3) & 0x01;
                Length_Freq_list = f[j+2] & 0x07;
                sprintf(desc, "Id_field=");
                switch (RandM) {
                    case 0x0:
                    case 0x1:
                        strcat(desc, "EId");
                        break;
                    case 0x6:
                        strcat(desc, "DRM Service Id");
                        break;
                    case 0x8:
                        strcat(desc, "RDS PI");
                        break;
                    case 0x9:
                    case 0xa:
                    case 0xc:
                        strcat(desc, "Dummy");
                        break;
                    case 0xe:
                        strcat(desc, "AMSS Service Id");
                        break;
                    default:
                        strcat(desc, "invalid");
                        break;
                }
                sprintf(tmpbuf, "=0x%X, R&M=0x%1x", Id_field, RandM);
                strcat(desc, tmpbuf);
                switch (RandM) {
                    case 0x0:
                        strcat(desc, "=DAB ensemble, no local windows");
                        break;
                    case 0x6:
                        strcat(desc, "=DRM");
                        break;
                    case 0x8:
                        strcat(desc, "=FM with RDS");
                        break;
                    case 0x9:
                        strcat(desc, "=FM without RDS");
                        break;
                    case 0xa:
                        strcat(desc, "=AM (MW in 9 kHz steps & LW)");
                        break;
                    case 0xc:
                        strcat(desc, "=AM (MW in 5 kHz steps & SW)");
                        break;
                    case 0xe:
                        strcat(desc, "=AMSS");
                        break;
                    default:
                        strcat(desc, "=Rfu");
                        break;
                }
                sprintf(tmpbuf, ", Continuity flag=%d", Continuity_flag);
                strcat(desc, tmpbuf);
                if ((fig0.oe() == 0) || ((fig0.oe() == 1) && (RandM != 0x6) && \
                            ((RandM < 0x8) || (RandM > 0xa)) && (RandM != 0xc) && (RandM != 0xe))) {
                    if (Continuity_flag == 0) {
                        switch (RandM) {
                            case 0x0:
                            case 0x1:
                                strcat(desc, "=continuous output not expected");
                                break;
                            case 0x6:
                                strcat(desc, "=no compensating time delay on DRM audio signal");
                                break;
                            case 0x8:
                            case 0x9:
                                strcat(desc, "=no compensating time delay on FM audio signal");
                                break;
                            case 0xa:
                            case 0xc:
                            case 0xe:
                                strcat(desc, "=no compensating time delay on AM audio signal");
                                break;
                            default:
                                strcat(desc, "=Rfu");
                                break;
                        }
                    }
                    else {  // Continuity_flag == 1
                        switch (RandM) {
                            case 0x0:
                            case 0x1:
                                strcat(desc, "=continuous output possible");
                                break;
                            case 0x6:
                                strcat(desc, "=compensating time delay on DRM audio signal");
                                break;
                            case 0x8:
                            case 0x9:
                                strcat(desc, "=compensating time delay on FM audio signal");
                                break;
                            case 0xa:
                            case 0xc:
                            case 0xe:
                                strcat(desc, "=compensating time delay on AM audio signal");
                                break;
                            default:
                                strcat(desc, "=Rfu");
                                break;
                        }
                    }
                }
                else {  // fig0.oe() == 1
                    strcat(desc, "=reserved for future addition");
                }
                key = ((uint64_t)fig0.oe() << 32) | ((uint64_t)fig0.pd() << 31) | \
                      ((uint64_t)RegionId << 20) | ((uint64_t)Id_field << 4) | \
                      (uint64_t)RandM;
                sprintf(tmpbuf, ", database key=0x%09" PRId64, key);
                // CEI Change Event Indication
                if (Length_Freq_list == 0) {
                    strcat(tmpbuf, ", CEI");
                }
                strcat(desc, tmpbuf);
                printbuf(desc, disp+2, NULL, 0);
                j += 3; // add header

                k = j;
                switch (RandM) {
                    case 0x0:
                    case 0x1:
                        while((k + 2) < (j + Length_Freq_list)) {
                            // iteration over Freq list
                            ifreq = (((uint32_t)(f[k] & 0x07) << 16) | ((uint32_t)f[k+1] << 8) | (uint32_t)f[k+2]) * 16;
                            if (ifreq != 0) {
                                Control_field = (f[k] >> 3);
                                Control_field_trans_mode = (Control_field >> 1) & 0x07;
                                if ((Control_field & 0x10) == 0) {
                                    sprintf(desc, "%d KHz, ", ifreq);
                                    if ((Control_field & 0x01) == 0) {
                                        strcat(desc, "geographically adjacent area, ");
                                    }
                                    else {  // (Control_field & 0x01) == 1
                                        strcat(desc, "no geographically adjacent area, ");
                                    }
                                    if (Control_field_trans_mode == 0) {
                                        strcat(desc, "no transmission mode signalled");
                                    }
                                    else if (Control_field_trans_mode <= 4) {
                                        sprintf(tmpbuf, "transmission mode %d", Control_field_trans_mode);
                                        strcat(desc, tmpbuf);
                                    }
                                    else {  // Control_field_trans_mode > 4
                                        sprintf(tmpbuf, "invalid transmission mode 0x%x", Control_field_trans_mode);
                                        strcat(desc, tmpbuf);
                                    }
                                }
                                else {  // (Control_field & 0x10) == 0x10
                                    sprintf(desc, "%d KHz, invalid Control field b23 0x%x", ifreq, Control_field);
                                }
                            }
                            else {
                                sprintf(desc, "Frequency not to be used (0)");
                            }
                            printbuf(desc, disp+3, NULL, 0);
                            k += 3;
                        }
                        break;
                    case 0x8:
                    case 0x9:
                    case 0xa:
                        while(k < (j + Length_Freq_list)) {
                            // iteration over Freq list
                            if (f[k] != 0) {    // freq != 0
                                if (RandM == 0xa) {
                                    if (f[k] < 16) {
                                        ifreq = (144 + ((uint32_t)f[k] * 9));
                                    }
                                    else {  // f[k] >= 16
                                        ifreq = (387 + ((uint32_t)f[k] * 9));
                                    }
                                    sprintf(desc, "%d KHz", ifreq);
                                }
                                else {  // RandM == 8 or 9
                                    freq = (87.5 + ((float)f[k] * 0.1));
                                    sprintf(desc, "%.1f MHz", freq);
                                }
                            }
                            else {
                                sprintf(desc, "Frequency not to be used (0)");
                            }
                            printbuf(desc, disp+3, NULL, 0);
                            k++;
                        }
                        break;
                    case 0xc:
                        while((k + 1) < (j + Length_Freq_list)) {
                            // iteration over Freq list
                            ifreq = (((uint32_t)f[k] << 8) | (uint32_t)f[k+1]) * 5;
                            if (ifreq != 0) {
                                sprintf(desc, "%d KHz", ifreq);
                            }
                            else {
                                sprintf(desc, "Frequency not to be used (0)");
                            }
                            printbuf(desc, disp+3, NULL, 0);
                            k += 2;
                        }
                        break;
                    case 0x6:
                    case 0xe:
                        while((k + 2) < (j + Length_Freq_list)) {
                            // iteration over Freq list
                            Id_field2 = f[k];
                            ifreq = ((((uint32_t)f[k+1] & 0x7f) << 8) | (uint32_t)f[k+2]);
                            if (ifreq != 0) {
                                sprintf(desc, "%d KHz", ifreq);
                            }
                            else {
                                sprintf(desc, "Frequency not to be used (0)");
                            }
                            if (RandM == 0x6) {
                                sprintf(tmpbuf, ", DRM Service Id 0x%X", Id_field2);
                                strcat(desc, tmpbuf);
                            }
                            else if (RandM == 0xe) {
                                sprintf(tmpbuf, ", AMSS Service Id 0x%X", Id_field2);
                                strcat(desc, tmpbuf);
                            }
                            if ((f[k+1] & 0x80) == 0x80) {
                                sprintf(tmpbuf, ", invalid Rfu b15 set to 1 instead of 0");
                                strcat(desc, tmpbuf);
                            }
                            printbuf(desc, disp+3, NULL, 0);
                            k += 3;
                        }
                        break;
                    default:
                        break;
                }
                j += Length_Freq_list;
            }
            i += Length_FI_list;
        }
    }

    return complete;
}