/* 
 * (c) danielinux 2019
 *
 *      GPLv.2
 *
 * See LICENSE for details
 */
#include <stdint.h>
#include "system.h"
#include "display.h"
#include "systick.h"
#include "button.h"
#include <stdlib.h>
#include <string.h>
#include "usecfs.h"

static const char welcome_message0[]= "  There is no  ";
static const char welcome_message1[]= "knowledge that ";
static const char welcome_message2[]= " is not power. ";

static const uint8_t uuid[UUID_LEN] = {
    0xb4, 0x6b, 0x82, 0x05, 0xb6, 0xcd, 0x28, 0xaa, 0xc7, 0x81, 0x2e, 0x2d,
    0xfd, 0xdd, 0x5e, 0x70, 0x3f, 0xbf, 0x09, 0x03, 0x1b, 0x5f, 0xbe, 0xc6,
    0x09, 0x62, 0xa8, 0x23, 0xe9, 0x99, 0x5e, 0xcb, 0xb4, 0xab, 0x28, 0xdc,
    0x14, 0xcb, 0x35, 0xb4, 0x7d, 0xfe, 0x26, 0x81, 0x33, 0xd0, 0x4b, 0xc2,
    0x49, 0x53, 0x05, 0xc3, 0xe7, 0xbd, 0x9a, 0x50, 0xb8, 0x01, 0x30, 0x0b,
    0x62, 0x58, 0xad, 0xba
};


static uint32_t last_action = 0;
static uint32_t offset = 0;

#define ST_LOCKED 0
#define ST_PIN_ENTRY 1
#define ST_UNLOCKED 2
#define MAX_PASSWORD 32

static int fsm_state = ST_LOCKED;

static char password[MAX_PASSWORD] = {};
static int pin_idx = 0;


#define SLEEP_TIME (5000)

void ui_msg(const char *txt)
{
    display_scroll(NULL, 0);
    display_clear(NULL);
    display_text(6, txt);
    last_action = jiffies;
}

void lock(void)
{
    //led_on(RED_LED);
    ui_msg("Locked.");
    fsm_state = ST_LOCKED;
}

int unlock(void)
{
    uint8_t stored_uuid[UUID_LEN];
    if (pin_idx < 6) {
        ui_msg("pin code too short");
        return -1;
    }
    display_scroll(NULL, 0);
    display_clear(NULL);
    display_text(6, "                ");
    display_text(5, "Unlocking secret");
    if ((usecfs_init(password, 0, stored_uuid) == 0) &&
            (memcmp(stored_uuid, uuid, UUID_LEN) == 0)) {
        memset(password, 0, MAX_PASSWORD);
        fsm_state = ST_UNLOCKED;
        ui_msg("Device UNLOCKED");
        return 0;
    } else {
#ifdef DEVICE_INITIALIZATION
        if (usecfs_init(password, 1, uuid) == 0) {
            display_text(6, "DEVICE INITIALIZED.");
            fsm_state = ST_UNLOCKED;
            return 0;
        }
#endif
        display_text(6, "Failed.");
        memset(password, 0, MAX_PASSWORD);
        pin_idx = 0;
        fsm_state = ST_LOCKED;
        return -1;
    }
}


void ui_button_hold(uint16_t button)
{
    last_action = jiffies;
}

void ui_sdcard_insert(void)
{
    ui_msg("SD Card detected");
    last_action = jiffies;
}

void ui_menu(char in)
{
    static uint8_t menu_scroll = 0;
    if (menu_scroll == 0) {
        display_scroll(NULL, 0);
        display_clear(NULL);
    }
    display_text(7, "1. Status       ");
    display_text(6, "0. Lockdown     ");
    display_text(5, "Main Menu       ");
    display_text(2, "4. Reboot       ");
    display_text(1, "3. SD format    ");
    display_text(0, "2. USB vault ON ");
    switch (in) {
        case  ' ':
            menu_scroll += 4;
            break;
        case '\r':
            menu_scroll -= 4;
            break;
    }
    menu_scroll %= 0x40;
    display_scroll(NULL, menu_scroll);
}

void ui_button_press(uint16_t button)
{
    int i;
    char c;
    if (fsm_state == ST_LOCKED) {
        ui_msg("Insert pin:");
        pin_idx = 0;
        memset(password, 0, MAX_PASSWORD);
        fsm_state = ST_PIN_ENTRY;
        return;
    }
    if (fsm_state == ST_PIN_ENTRY) {
        char line[17] = "                ";
        for (i = 0; i < pin_idx; i++) {
            line[i] = '*';
        }
        c = bu2c(button);
        if ((c >= '0') && (c <='9')) {
            if (pin_idx < 16) {
                line[pin_idx] = 'X';
            }
            password[pin_idx++] = bu2c(button);
        }
        if (c == '\r') {
            unlock();
        } else {
            display_scroll(NULL, 0);
            display_clear(NULL);
            display_text(7, line);
            display_text(6, "Insert pin:");
        }
    }
    if (fsm_state == ST_UNLOCKED)
    {
        ui_menu(bu2c(button));
    }
    last_action = jiffies;
}

void ui_init(void)
{
    uint32_t now;
    int i;
    display_scroll(NULL, 0x3f);
    display_text(0, welcome_message0);
    display_text(1, welcome_message1);
    display_text(2, welcome_message2);
    now = jiffies;
    for (i = 0x3f; i >= 0x20; i--) {
        display_scroll(NULL, i);
        while ((jiffies - now) < 50)
            WFI();
        now = jiffies;
    }
    for (i = display_getcontrast(NULL); i >= 0; i--) {
        display_setcontrast(NULL, i);
        while ((jiffies - now) < 10)
            WFI();
        now = jiffies;
    }
    display_scroll(NULL, 0);
    display_clear(NULL);
    display_setcontrast(NULL, 0xcf);
    lock();
}

void ui_keepalive(uint32_t timeslice)
{
    if ((jiffies - last_action) > SLEEP_TIME) {
        display_scroll(NULL, 0);
        display_clear(NULL);
        if (fsm_state == ST_PIN_ENTRY)
            lock();
    }
}