/**
 * Copyright (c) 2017-2018 Tara Keeling
 *				 2020 Philippe G. 
 * 
 * This software is released under the MIT License.
 * https://opensource.org/licenses/MIT
 */

#include <string.h>
#include <ctype.h>
#include <stdint.h>
#include <math.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/gpio.h"
#include "driver/ledc.h"
#include "esp_log.h"
#include "Config.h"
#include "gds.h"
#include "gds_private.h"

#ifdef CONFIG_IDF_TARGET_ESP32S3
#define LEDC_SPEED_MODE LEDC_LOW_SPEED_MODE
#else
#define LEDC_SPEED_MODE LEDC_HIGH_SPEED_MODE
#endif
extern bool gds_init_fonts();
static struct GDS_Device Display;
static struct GDS_BacklightPWM PWMConfig;

static char TAG[] = "gds";

struct GDS_Device* GDS_AutoDetect(sys_display_config* Driver, GDS_DetectFunc* DetectFunc[], struct GDS_BacklightPWM* PWM) {
    if(!Driver->has_common || Driver->common.driver == sys_display_drivers_UNSPECIFIED) return NULL;
    if(PWM) PWMConfig = *PWM;

    for(int i = 0; DetectFunc[i]; i++) {
        if(DetectFunc[i](Driver, &Display)) {
            if(PWM && PWM->Init) {
                ledc_timer_config_t PWMTimer = {
                    .duty_resolution = LEDC_TIMER_13_BIT,
                    .freq_hz = 5000,
                    .speed_mode = LEDC_SPEED_MODE,
                    .timer_num = PWMConfig.Timer,
                };
                ledc_timer_config(&PWMTimer);
            }
            ESP_LOGD(TAG, "Detected driver %p with PWM %d", &Display, PWM ? PWM->Init : 0);
            return &Display;
        }
    }

    return NULL;
}

void GDS_ClearExt(struct GDS_Device* Device, bool full, ...) {
    bool commit = true;

    if(full) {
        GDS_Clear(Device, GDS_COLOR_BLACK);
    } else {
        va_list args;
        va_start(args, full);
        commit = va_arg(args, int);
        int x1 = va_arg(args, int), y1 = va_arg(args, int), x2 = va_arg(args, int), y2 = va_arg(args, int);
        if(x2 < 0) x2 = Device->Width - 1;
        if(y2 < 0) y2 = Device->Height - 1;
        GDS_ClearWindow(Device, x1, y1, x2, y2, GDS_COLOR_BLACK);
        va_end(args);
    }

    Device->Dirty = true;
    if(commit) GDS_Update(Device);
}

void GDS_Clear(struct GDS_Device* Device, int Color) {
    if(Color == GDS_COLOR_BLACK)
        memset(Device->Framebuffer, 0, Device->FramebufferSize);
    else if(Device->Depth == 1)
        memset(Device->Framebuffer, 0xff, Device->FramebufferSize);
    else if(Device->Depth == 4)
        memset(Device->Framebuffer, Color | (Color << 4), Device->FramebufferSize);
    else if(Device->Depth == 8)
        memset(Device->Framebuffer, Color, Device->FramebufferSize);
    else
        GDS_ClearWindow(Device, 0, 0, -1, -1, Color);
    Device->Dirty = true;
}

#define CLEAR_WINDOW(x1, y1, x2, y2, F, W, C, T, N)                                                                                                  \
    for(int y = y1; y <= y2; y++) {                                                                                                                  \
        T* Ptr = (T*)F + (y * W + x1) * N;                                                                                                           \
        for(int c = (x2 - x1) * N; c-- >= 0; *Ptr++ = C);                                                                                            \
    }

void GDS_ClearWindow(struct GDS_Device* Device, int x1, int y1, int x2, int y2, int Color) {
    // -1 means up to width/height
    if(x2 < 0) x2 = Device->Width - 1;
    if(y2 < 0) y2 = Device->Height - 1;

    // driver can provide own optimized clear window
    if(Device->ClearWindow) {
        Device->ClearWindow(Device, x1, y1, x2, y2, Color);
    } else if(Device->Depth == 1) {
        // single shot if we erase all screen
        if(x2 - x1 == Device->Width - 1 && y2 - y1 == Device->Height - 1) {
            memset(Device->Framebuffer, Color == GDS_COLOR_BLACK ? 0 : 0xff, Device->FramebufferSize);
        } else {
            uint8_t _Color = Color == GDS_COLOR_BLACK ? 0 : 0xff;
            uint8_t Width = Device->Width >> 3;
            uint8_t* optr = Device->Framebuffer;
            // try to do byte processing as much as possible
            for(int r = y1; r <= y2;) {
                int c = x1;
                // for a row that is not on a boundary, no optimization possible
                while(r & 0x07 && r <= y2) {
                    for(c = x1; c <= x2; c++) DrawPixelFast(Device, c, r, Color);
                    r++;
                }
                // go fast if we have more than 8 lines to write
                if(r + 8 <= y2) {
                    memset(optr + Width * r + x1, _Color, x2 - x1 + 1);
                    r += 8;
                } else
                    while(r <= y2) {
                        for(c = x1; c <= x2; c++) DrawPixelFast(Device, c, r, Color);
                        r++;
                    }
            }
        }
    }
    if(Device->Depth == 4) {
        if(x2 - x1 == Device->Width - 1 && y2 - y1 == Device->Height - 1) {
            // we assume color is 0..15
            memset(Device->Framebuffer, Color | (Color << 4), Device->FramebufferSize);
        } else {
            uint8_t _Color = Color | (Color << 4);
            int Width = Device->Width;
            uint8_t* optr = Device->Framebuffer;
            // try to do byte processing as much as possible
            for(int r = y1; r <= y2; r++) {
                int c = x1;
                if(c & 0x01) DrawPixelFast(Device, c++, r, Color);
                int chunk = (x2 - c + 1) >> 1;
                memset(optr + ((r * Width + c) >> 1), _Color, chunk);
                if(c + chunk <= x2) DrawPixelFast(Device, x2, r, Color);
            }
        }
    } else if(Device->Depth == 8) {
        CLEAR_WINDOW(x1, y1, x2, y2, Device->Framebuffer, Device->Width, Color, uint8_t, 1);
    } else if(Device->Depth == 16) {
        CLEAR_WINDOW(x1, y1, x2, y2, Device->Framebuffer, Device->Width, Color, uint16_t, 1);
    } else if(Device->Depth == 24) {
        CLEAR_WINDOW(x1, y1, x2, y2, Device->Framebuffer, Device->Width, Color, uint8_t, 3);
    } else {
        for(int y = y1; y <= y2; y++) {
            for(int x = x1; x <= x2; x++) { DrawPixelFast(Device, x, y, Color); }
        }
    }

    // make sure diplay will do update
    Device->Dirty = true;
}

void GDS_Update(struct GDS_Device* Device) {
    if(Device->Dirty) Device->Update(Device);
    Device->Dirty = false;
}

bool GDS_Reset(struct GDS_Device* Device) {
    if(Device->RSTPin >= 0) {
        gpio_set_level(Device->RSTPin, 0);
        vTaskDelay(pdMS_TO_TICKS(100));
        gpio_set_level(Device->RSTPin, 1);
    }
    return true;
}

bool GDS_Init(struct GDS_Device* Device) {

    if(Device->Depth > 8)
        Device->FramebufferSize = Device->Width * Device->Height * ((8 + Device->Depth - 1) / 8);
    else
        Device->FramebufferSize = (Device->Width * Device->Height) / (8 / Device->Depth);

    // allocate FB unless explicitely asked not to
    if(!(Device->Alloc & GDS_ALLOC_NONE)) {
        if((Device->Alloc & GDS_ALLOC_IRAM) || ((Device->Alloc & GDS_ALLOC_IRAM_SPI) && Device->IF == GDS_IF_SPI)) {
            Device->Framebuffer = heap_caps_calloc(1, Device->FramebufferSize, MALLOC_CAP_INTERNAL | MALLOC_CAP_DMA);
        } else {
            Device->Framebuffer = calloc(1, Device->FramebufferSize);
        }
        NullCheck(Device->Framebuffer, return false);
    }

    if(Device->Backlight.Pin >= 0) {
        Device->Backlight.Channel = PWMConfig.Channel++;
        Device->Backlight.PWM = PWMConfig.Max - 1;

        ledc_channel_config_t PWMChannel = {
            .channel = Device->Backlight.Channel,
            .duty = Device->Backlight.PWM,
            .gpio_num = Device->Backlight.Pin,
            .speed_mode = LEDC_SPEED_MODE,
            .hpoint = 0,
            .timer_sel = PWMConfig.Timer,
        };

        ledc_channel_config(&PWMChannel);
    }

    bool Res = Device->Init(Device);
    if(Res) { Res = gds_init_fonts(); }
    if(!Res && Device->Framebuffer) free(Device->Framebuffer);

    return Res;
}

int GDS_GrayMap(struct GDS_Device* Device, uint8_t Level) {
    switch(Device->Mode) {
    case GDS_MONO:
        return Level;
    case GDS_GRAYSCALE:
        return Level >> (8 - Device->Depth);
    case GDS_RGB332:
        Level >>= 5;
        return (Level << 6) | (Level << 3) | (Level >> 1);
    case GDS_RGB444:
        Level >>= 4;
        return (Level << 8) | (Level << 4) | Level;
    case GDS_RGB555:
        Level >>= 3;
        return (Level << 10) | (Level << 5) | Level;
    case GDS_RGB565:
        Level >>= 2;
        return ((Level & ~0x01) << 10) | (Level << 5) | (Level >> 1);
    case GDS_RGB666:
        Level >>= 2;
        return (Level << 12) | (Level << 6) | Level;
    case GDS_RGB888:
        return (Level << 16) | (Level << 8) | Level;
    }

    return -1;
}

void GDS_SetContrast(struct GDS_Device* Device, uint8_t Contrast) {
    if(Device->SetContrast)
        Device->SetContrast(Device, Contrast);
    else if(Device->Backlight.Pin >= 0) {
        Device->Backlight.PWM = PWMConfig.Max * powf(Contrast / 255.0, 3);
        ledc_set_duty(LEDC_SPEED_MODE, Device->Backlight.Channel, Device->Backlight.PWM);
        ledc_update_duty(LEDC_SPEED_MODE, Device->Backlight.Channel);
    }
}

void GDS_SetLayout(struct GDS_Device* Device, struct GDS_Layout* Layout) {
    if(Device->SetLayout) Device->SetLayout(Device, Layout);
}
void GDS_SetDirty(struct GDS_Device* Device) { Device->Dirty = true; }
int GDS_GetWidth(struct GDS_Device* Device) { return Device ? Device->Width : 0; }
void GDS_SetTextWidth(struct GDS_Device* Device, int TextWidth) {
    Device->TextWidth = Device && TextWidth && TextWidth < Device->Width ? TextWidth : Device->Width;
}
int GDS_GetHeight(struct GDS_Device* Device) { return Device ? Device->Height : 0; }
int GDS_GetDepth(struct GDS_Device* Device) { return Device ? Device->Depth : 0; }
int GDS_GetMode(struct GDS_Device* Device) { return Device ? Device->Mode : 0; }
void GDS_DisplayOn(struct GDS_Device* Device) {
    if(Device->DisplayOn) Device->DisplayOn(Device);
}
void GDS_DisplayOff(struct GDS_Device* Device) {
    if(Device->DisplayOff) Device->DisplayOff(Device);
}