/*
 * This file is part of the Pico HSM distribution (https://github.com/polhenarejos/pico-hsm).
 * Copyright (c) 2022 Pol Henarejos.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, version 3.
 *
 * 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
 * Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <https://www.gnu.org/licenses/>.
 */

#include "sc_hsm.h"
#include "version.h"

void select_file(file_t *pe) {
    if (!pe) {
        currentDF = (file_t *) MF;
        currentEF = NULL;
    }
    else if (pe->type & (FILE_TYPE_INTERNAL_EF|FILE_TYPE_WORKING_EF)) {
        currentEF = pe;
        currentDF = &file_entries[pe->parent];
    }
    else {
        currentDF = pe;
    }
    if (currentEF == file_openpgp || currentEF == file_sc_hsm) {
        selected_applet = currentEF;
        //sc_hsm_unload(); //reset auth status
    }
}

int cmd_select() {
    uint8_t p1 = P1(apdu);
    uint8_t p2 = P2(apdu);
    file_t *pe = NULL;
    uint16_t fid = 0x0;

    // Only "first or only occurence" supported
    //if ((p2 & 0xF3) != 0x00) {
    //    return SW_INCORRECT_P1P2();
    //}

    if (apdu.nc == 2) {
        fid = get_uint16_t_be(apdu.data);
    }

    //if ((fid & 0xff00) == (KEY_PREFIX << 8))
    //    fid = (PRKD_PREFIX << 8) | (fid & 0xff);

    /*uint8_t pfx = fid >> 8;*/
    /*if (pfx == PRKD_PREFIX ||
        pfx == CD_PREFIX ||
        pfx == CA_CERTIFICATE_PREFIX ||
        pfx == KEY_PREFIX ||
        pfx == EE_CERTIFICATE_PREFIX ||
        pfx == DCOD_PREFIX ||
        pfx == DATA_PREFIX ||
        pfx == PROT_DATA_PREFIX) {*/
    if (fid != 0x0 && !(pe = search_file(fid))) {
        return SW_FILE_NOT_FOUND();
    }
    /*}*/
    if (!pe) {
        if (p1 == 0x0) { //Select MF, DF or EF - File identifier or absent
            if (apdu.nc == 0) {
                pe = (file_t *) MF;
                //ac_fini();
            }
            else if (apdu.nc == 2) {
                if (!(pe = search_by_fid(fid, NULL, SPECIFY_ANY))) {
                    return SW_FILE_NOT_FOUND();
                }
            }
        }
        else if (p1 == 0x01) {   //Select child DF - DF identifier
            if (!(pe = search_by_fid(fid, currentDF, SPECIFY_DF))) {
                return SW_FILE_NOT_FOUND();
            }
        }
        else if (p1 == 0x02) {   //Select EF under the current DF - EF identifier
            if (!(pe = search_by_fid(fid, currentDF, SPECIFY_EF))) {
                return SW_FILE_NOT_FOUND();
            }
        }
        else if (p1 == 0x03) {   //Select parent DF of the current DF - Absent
            if (apdu.nc != 0) {
                return SW_FILE_NOT_FOUND();
            }
        }
        else if (p1 == 0x04) {   //Select by DF name - e.g., [truncated] application identifier
            if (!(pe = search_by_name(apdu.data, (uint16_t)apdu.nc))) {
                return SW_FILE_NOT_FOUND();
            }
            if (card_terminated) {
                return set_res_sw(0x62, 0x85);
            }
        }
        else if (p1 == 0x08) {   //Select from the MF - Path without the MF identifier
            if (!(pe = search_by_path(apdu.data, (uint8_t)apdu.nc, MF))) {
                return SW_FILE_NOT_FOUND();
            }
        }
        else if (p1 == 0x09) {   //Select from the current DF - Path without the current DF identifier
            if (!(pe = search_by_path(apdu.data, (uint8_t)apdu.nc, currentDF))) {
                return SW_FILE_NOT_FOUND();
            }
        }
    }
    if ((p2 & 0xfc) == 0x00 || (p2 & 0xfc) == 0x04) {
        process_fci(pe, 0);
        if (pe == file_sc_hsm) {
            res_APDU[res_APDU_size++] = 0x85;
            res_APDU[res_APDU_size++] = 5;
            uint16_t opts = get_device_options();
            res_APDU_size += put_uint16_t_be(opts, res_APDU + res_APDU_size);
            res_APDU[res_APDU_size++] = 0xFF;
            res_APDU[res_APDU_size++] = HSM_VERSION_MAJOR;
            res_APDU[res_APDU_size++] = HSM_VERSION_MINOR;
            res_APDU[1] = (uint8_t)res_APDU_size - 2;
        }
    }
    else {
        return SW_INCORRECT_P1P2();
    }
    select_file(pe);
    return SW_OK();
}