#include "main.h"

#include "stm32l100c_discovery.h"

#include "ssd1306.h"

// USB includes

#include "hw_config.h"

#include "usb_lib.h"

#include "usb_desc.h"

#include "usb_pwr.h"

#include "stringhelpers.h"

// TODO: Grab buttonpresses with interrupts

// TODO: Eliminate screen buffer since we aren't using it...

// USB Supporting Vars

extern __IO uint8_t Receive_Buffer[64];

extern __IO  uint32_t Receive_length ;

extern __IO  uint32_t length ;

uint8_t Send_Buffer[64];

uint32_t packet_sent=1;

uint32_t packet_receive=1;

// State definition

enum state {

    STATE_IDLE = 0,

    STATE_SETP,

    STATE_SETI,

    STATE_SETD,

    STATE_PREHEAT_BREW,

    STATE_MAINTAIN_BREW,

    STATE_PREHEAT_STEAM,

    STATE_MAINTAIN_STEAM,

};

static __IO uint32_t TimingDelay;

// Move to header file

void init_gpio();

void init_spi();

void process();

void machine();

int main(void)

{

    // Init clocks

    SystemInit();

    // Init GPIO

    init_gpio();

    // Init USB

    //Set_USBClock();

    //USB_Interrupts_Config();

    //USB_Init();

    // Turn on power LED

    GPIO_SetBits(LED_POWER);

    // TODO: Awesome pwm of power LED (TIM4_CH4 or TIM11_CH1)

    // TODO: PWM of stat led (TIM3_CH2)

    // Configure 1ms SysTick (change if more temporal resolution needed) 

    RCC_ClocksTypeDef RCC_Clocks;

    RCC_GetClocksFreq(&RCC_Clocks);

    SysTick_Config(RCC_Clocks.HCLK_Frequency / 1000);

    // Init SPI busses

    init_spi();

    // Init OLED over SPI

    ssd1306_Init();

    ssd1306_block_write();

    // Startup screen 

    ssd1306_DrawString("therm v0.1", 1, 40);

    ssd1306_DrawString("protofusion.org/therm", 3, 0);

    Delay(1500);

    ssd1306_block_write();

    // Main loop

    while(1)

    {

        // Process sensor inputs

        process();

        // Run state machine

        machine(); 

    }

}

// Read temperature and update global temp vars

int16_t temp = 0;

uint8_t temp_frac = 0;

void update_temp() {

    // Assert CS

    GPIO_ResetBits(MAX_CS);

    Delay(1);

    // This may not clock at all... might need to send 16 bits first

    SPI_I2S_SendData(SPI2, 0xAAAA); // send dummy data

    //SPI_I2S_SendData(SPI2, 0xAA); // send dummy data

    uint16_t temp_pre = SPI_I2S_ReceiveData(SPI2);

    if(temp_pre & 0b0000000000000010) {

        ssd1306_DrawString("Fatal Error", 2, 35);

    }

    else if(temp_pre & 0b0000000000000001) {

        ssd1306_DrawString("Error: No TC", 2, 40);

        temp = 0;

        temp_frac = 0;

    }

    else 

    {

        uint8_t sign = temp >> 15;// top bit is sign

        temp_pre = temp_pre >> 2; // Drop 2 lowest bits

        temp_frac = temp_pre & 0b11; // get fractional part

        temp_frac *= 25; // each bit is .25 a degree, up to fixed point

        temp_pre = temp_pre >> 2; // Drop 2 fractional bits 

        if(sign) {

            temp = -temp_pre;

        }

        else {

            temp = temp_pre;

        }

    }

    // Deassert CS

    Delay(1);

    GPIO_SetBits(MAX_CS);

}

uint32_t ticks = 0;

uint32_t last_ssr_on = 0;

uint32_t last_led = 0;

int32_t setpoint = 0;

uint16_t k_p = 1;

uint16_t k_i = 1;

uint16_t k_d = 1;

uint8_t ssr_output = 0; // Duty cycle of ssr, 0 to SSR_PERIOD 

// Process things

void process()

{

    update_temp(); // Read MAX31855

    // TODO: Add calibration offset (linear)

    if(ticks - last_led > 400) 

    {

        GPIO_ToggleBits(LED_POWER);

        last_led = ticks;

    }

    // Every 200ms, set the SSR on

    if(ticks - last_ssr_on > SSR_PERIOD)

    {

        GPIO_SetBits(LED_STAT);

        last_ssr_on = ticks;

    }

    // Kill SSR after elapsed period less than SSR_PERIOD 

    if(ticks - last_ssr_on > ssr_output || !ssr_output)

    {

        GPIO_ResetBits(LED_STAT);

    }

}

void draw_setpoint() {

    char tempstr[3];

    itoa_fp(temp, temp_frac, tempstr);

    //ssd1306_DrawString("        ", 3, 40);

    ssd1306_DrawString(tempstr, 3, 40);

    ssd1306_DrawString("-> ", 3, 80);

    itoa(setpoint, tempstr);

    ssd1306_DrawString("    ", 3, 95);

    ssd1306_DrawString(tempstr, 3, 95);

}

uint8_t state = STATE_IDLE;

uint8_t goto_mode = 2;

// State machine

void machine()

{

    uint8_t last_state = state;

    switch(state)

    {

        // Idle state

        case STATE_IDLE:

        {

            // Write text to OLED

            // [ therm :: idle ]

            ssd1306_DrawString("therm :: idle ", 0, 40);

            char tempstr[6];

            itoa_fp(temp, temp_frac, tempstr);

            ssd1306_DrawString("Temp: ", 3, 40);

            ssd1306_DrawString("    ", 3, 70);

            ssd1306_DrawString(tempstr, 3, 72);

            ssd1306_drawlogo();

            switch(goto_mode) {

                case 2:

                {

                    ssd1306_DrawString("-> brew     ", 1, 40);

                } break;

                case 1:

                {

                    ssd1306_DrawString("-> set P/I/D", 1, 40);

                } break;

                case 0:

                {

                    ssd1306_DrawString("-> setup    ", 1, 40);

                } break;

            }

            // Button handler

            if(!GPIO_ReadInputDataBit(SW_BTN)) {

                switch(goto_mode) {

                    case 2:

                        state = STATE_PREHEAT_BREW;

                        break;

                    case 1:

                        state = STATE_SETP;

                        break;

                    case 0:

                        state = STATE_SETP;

                        break;

                    default:

                        state = STATE_PREHEAT_BREW;

                }

            }

            else if(!GPIO_ReadInputDataBit(SW_UP) && goto_mode < 2) {

                goto_mode++;

            }

            else if(!GPIO_ReadInputDataBit(SW_DOWN) && k_p > 0 && goto_mode > 0) {

                goto_mode--;

            }

            // Event Handler

            // N/A

        } break;

        case STATE_SETP:

        {

            // Write text to OLED

            // [ therm :: set p ]

            // [ p = 12         ]

            ssd1306_DrawString("Proportional", 0, 40);

            char tempstr[6];

            itoa(k_p, tempstr);

            ssd1306_DrawString("P=", 1, 45);

            ssd1306_DrawString("    ", 1, 57);

            ssd1306_DrawString(tempstr, 1, 57);

            ssd1306_DrawString("Press to accept", 3, 40);

            // Button handler

            if(!GPIO_ReadInputDataBit(SW_BTN)) {

                state = STATE_SETI;

            }

            else if(!GPIO_ReadInputDataBit(SW_UP)) {

                k_p++;

            }

            else if(!GPIO_ReadInputDataBit(SW_DOWN) && k_p > 0) {

                k_p--;

            }

            // Event Handler

            // N/A

        } break;

        case STATE_SETI:

        {

            // Write text to OLED

            // [ therm :: set i ]

            // [ i = 12         ]

            ssd1306_DrawString("Integral", 0, 40);

            char tempstr[6];

            itoa(k_i, tempstr);

            ssd1306_DrawString("I=", 1, 45);

            ssd1306_DrawString("    ", 1, 57);

            ssd1306_DrawString(tempstr, 1, 57);

            ssd1306_DrawString("Press to accept", 3, 40);

            // Button handler

            if(!GPIO_ReadInputDataBit(SW_BTN)) {

                state = STATE_SETD;

            }

            else if(!GPIO_ReadInputDataBit(SW_UP)) {

                k_i++;

            }

            else if(!GPIO_ReadInputDataBit(SW_DOWN) && k_i > 0) {

                k_i--;

            }

            // Event Handler

            // N/A

        } break;

        case STATE_SETD:

        {

            // Write text to OLED

            // [ therm :: set d ]

            // [ d = 12         ]

            ssd1306_DrawString("Derivative", 0, 40);

            char tempstr[6];

            itoa(k_d, tempstr);

            ssd1306_DrawString("D=", 1, 45);

            ssd1306_DrawString("    ", 1, 57);

            ssd1306_DrawString(tempstr, 1, 57);

            ssd1306_DrawString("Press to accept", 3, 40);

            // Button handler

            if(!GPIO_ReadInputDataBit(SW_BTN)) {

                state = STATE_IDLE;

            }

            else if(!GPIO_ReadInputDataBit(SW_UP)) {

                k_d++;

            }

            else if(!GPIO_ReadInputDataBit(SW_DOWN) && k_d > 0) {

                k_d--;

            }

            // Event Handler

            // N/A

        } break;

        case STATE_PREHEAT_BREW:

        {

            // Write text to OLED

            // [ therm : preheating brew ]

            // [ 30 => 120 C             ]

            ssd1306_DrawString("Preheating...", 0, 40);

            draw_setpoint();

            // Button handler

            if(!GPIO_ReadInputDataBit(SW_BTN)) {

                state = STATE_IDLE;

            }

            // Event Handler

            if(temp >= setpoint) {

                state = STATE_MAINTAIN_BREW;

            }

        } break;

        case STATE_MAINTAIN_BREW:

        {

            // Write text to OLED

            // [ therm : ready to brew ]

            // [ 30 => 120 C           ]

            ssd1306_DrawString("Ready to Brew!", 0, 40);

            draw_setpoint();

            // Button handler

            if(!GPIO_ReadInputDataBit(SW_BTN)) {

                state = STATE_IDLE;

            }

            // Event Handler

            // N/A

        } break;

        case STATE_PREHEAT_STEAM:

        {

            // Write text to OLED

            // [ therm : preheating steam ]

            // [ 30 => 120 C           ]

            ssd1306_DrawString("Preheating...", 0, 40);

            draw_setpoint();

            // Button handler

            if(!GPIO_ReadInputDataBit(SW_BTN)) {

                state = STATE_IDLE;

            }

            // Event Handler

            if(temp >= setpoint) {

                state = STATE_MAINTAIN_STEAM;

            }

        } break;

        case STATE_MAINTAIN_STEAM:

        {

            // Write text to OLED

            // [ therm : ready to steam ]

            // [ 30 => 120 C            ]

            ssd1306_DrawString("Ready to Steam!", 0, 40);

            draw_setpoint();

            // Button handler