#include <furi.h>

#include <dialogs/dialogs.h>
#include <gui/gui.h>
#include <storage/storage.h>

#include <lib/flipper_format/flipper_format.h>

// this file is generated by the build script
#include <qrcode_icons.h>
#include "qrcode.h"

#define TAG "qrcode"
#define QRCODE_FOLDER ANY_PATH("qrcodes")
#define QRCODE_EXTENSION ".qrcode"
#define QRCODE_FILETYPE "QRCode"
#define QRCODE_FILE_VERSION 0

/**
 * Maximum version is 11 because the f0 screen is only 64 pixels high and
 * version 12 is 65x65. Version 11 is 61x61.
 */
#define MAX_QRCODE_VERSION 11

/** Maximum length by mode, ecc, and version */
static const uint16_t MAX_LENGTH[3][4][MAX_QRCODE_VERSION] = {
    {
        // Numeric
        {41, 77, 127, 187, 255, 322, 370, 461, 552, 652, 772}, // Low
        {34, 63, 101, 149, 202, 255, 293, 365, 432, 513, 604}, // Medium
        {27, 48, 77, 111, 144, 178, 207, 259, 312, 364, 427},  // Quartile
        {17, 34, 58, 82, 106, 139, 154, 202, 235, 288, 331},   // High
    },
    {
        // Alphanumeric
        {25, 47, 77, 114, 154, 195, 224, 279, 335, 395, 468}, // Low
        {20, 38, 61, 90, 122, 154, 178, 221, 262, 311, 366},  // Medium
        {16, 29, 47, 67, 87, 108, 125, 157, 189, 221, 259},   // Quartile
        {10, 20, 35, 50, 64, 84, 93, 122, 143, 174, 200},     // High
    },
    {
        // Binary
        {17, 32, 53, 78, 106, 134, 154, 192, 230, 271, 321}, // Low
        {14, 26, 42, 62, 84, 106, 122, 152, 180, 213, 251},  // Medium
        {11, 20, 32, 46, 60, 74, 86, 108, 130, 151, 177},    // Quartile
        {7, 14, 24, 34, 44, 58, 64, 84, 98, 119, 137},       // High
    },
};

/** Main app instance */
typedef struct {
    FuriMessageQueue* input_queue;
    Gui* gui;
    ViewPort* view_port;

    FuriMutex** mutex;
    FuriString* message;
    QRCode* qrcode;
    uint8_t min_version;
    uint8_t max_ecc_at_min_version;
    bool loading;
    bool too_long;
    bool show_stats;
    uint8_t selected_idx;
    bool edit;
    uint8_t set_version;
    uint8_t set_ecc;
} QRCodeApp;

/**
 * @param ecc ECC number
 * @returns a character corresponding to the ecc level
 */
static char get_ecc_char(uint8_t ecc) {
    switch (ecc) {
        case 0: return 'L';
        case 1: return 'M';
        case 2: return 'Q';
        case 3: return 'H';
        default: return '?';
    }
}

/**
 * @param mode qrcode mode
 * @returns a character corresponding to the mode
 */
static char get_mode_char(uint8_t mode) {
    switch (mode) {
        case 0: return 'N';
        case 1: return 'A';
        case 2: return 'B';
        case 3: return 'K';
        default: return '?';
    }
}

/**
 * Render
 * @param canvas The canvas to render to
 * @param ctx Context provided to the callback by view_port_draw_callback_set
 */
static void render_callback(Canvas* canvas, void* ctx) {
    furi_assert(canvas);
    furi_assert(ctx);

    QRCodeApp* instance = ctx;
    furi_check(furi_mutex_acquire(instance->mutex, FuriWaitForever) == FuriStatusOk);

    canvas_clear(canvas);
    canvas_set_color(canvas, ColorBlack);
    canvas_set_font(canvas, FontPrimary);

    uint8_t font_height = canvas_current_font_height(canvas);
    uint8_t width = canvas_width(canvas);
    uint8_t height = canvas_height(canvas);
    if (instance->loading) {
        canvas_draw_str_aligned(canvas, width / 2, height / 2, AlignCenter, AlignCenter, "Loading...");
    } else if (instance->qrcode) {
        uint8_t size = instance->qrcode->size;
        uint8_t pixel_size = height / size;
        uint8_t top = (height - pixel_size * size) / 2;
        uint8_t left = ((instance->show_stats ? 65 : width) - pixel_size * size) / 2;
        for (uint8_t y = 0; y < size; y++) {
            for (uint8_t x = 0; x < size; x++) {
                if (qrcode_getModule(instance->qrcode, x, y)) {
                    if (pixel_size == 1) {
                        canvas_draw_dot(canvas, left + x * pixel_size, top + y * pixel_size);
                    } else {
                        canvas_draw_box(canvas, left + x * pixel_size, top + y * pixel_size, pixel_size, pixel_size);
                    }
                }
            }
        }

        if (instance->show_stats) {
            top = 10;
            left = 66;

            FuriString* str = furi_string_alloc();

            if (!instance->edit || instance->selected_idx == 0) {
                furi_string_printf(str, "Ver: %i", instance->set_version);
                canvas_draw_str(canvas, left + 5, top + font_height, furi_string_get_cstr(str));
                if (instance->selected_idx == 0) {
                    canvas_draw_triangle(canvas, left, top + font_height / 2, font_height - 4, 4, CanvasDirectionLeftToRight);
                }
                if (instance->edit) {
                    uint8_t arrow_left = left + 5 + canvas_string_width(canvas, "Ver: 8") / 2;
                    canvas_draw_triangle(canvas, arrow_left, top, font_height - 4, 4, CanvasDirectionBottomToTop);
                    canvas_draw_triangle(canvas, arrow_left, top + font_height + 1, font_height - 4, 4, CanvasDirectionTopToBottom);
                }
            }

            if (!instance->edit || instance->selected_idx == 1) {
                furi_string_printf(str, "ECC: %c", get_ecc_char(instance->set_ecc));
                canvas_draw_str(canvas, left + 5, 2 * font_height + top + 2, furi_string_get_cstr(str));
                if (instance->selected_idx == 1) {
                    canvas_draw_triangle(canvas, left, 3 * font_height / 2 + top + 2, font_height - 4, 4, CanvasDirectionLeftToRight);
                }
                if (instance->edit) {
                    uint8_t arrow_left = left + 5 + canvas_string_width(canvas, "ECC: H") / 2;
                    canvas_draw_triangle(canvas, arrow_left, font_height + top + 2, font_height - 4, 4, CanvasDirectionBottomToTop);
                    canvas_draw_triangle(canvas, arrow_left, 2 * font_height + top + 3, font_height - 4, 4, CanvasDirectionTopToBottom);
                }
            }

            if (!instance->edit) {
                furi_string_printf(str, "Mod: %c", get_mode_char(instance->qrcode->mode));
                canvas_draw_str(canvas, left + 5, 3 * font_height + top + 4, furi_string_get_cstr(str));
            }

            furi_string_free(str);
        }
    } else {
        uint8_t margin = (height - font_height * 2) / 3;
        canvas_draw_str_aligned(canvas, width / 2, margin, AlignCenter, AlignTop, "Could not load qrcode.");
        if (instance->too_long) {
            canvas_set_font(canvas, FontSecondary);
            canvas_draw_str(canvas, width / 2, margin * 2 + font_height, "Message is too long.");
        }
    }

    furi_mutex_release(instance->mutex);
}

/**
 * Handle input
 * @param input_event The received input event
 * @param ctx Context provided to the callback by view_port_input_callback_set
 */
static void input_callback(InputEvent* input_event, void* ctx) {
    furi_assert(input_event);
    furi_assert(ctx);
    if (input_event->type == InputTypeShort) {
        QRCodeApp* instance = ctx;
        furi_message_queue_put(instance->input_queue, input_event, 0);
    }
}

/**
 * Determine if the given string is all numeric
 * @param str The string to test
 * @returns true if the string is all numeric
 */
static bool is_numeric(const char* str, uint16_t len) {
    furi_assert(str);
    while (len > 0) {
        char c = str[--len];
        if (c < '0' || c > '9') return false;
    }
    return true;
}

/**
 * Determine if the given string is alphanumeric
 * @param str The string to test
 * @returns true if the string is alphanumeric
 */
static bool is_alphanumeric(const char* str, uint16_t len) {
    furi_assert(str);
    while (len > 0) {
        char c = str[--len];
        if (c >= '0' && c <= '9') continue;
        if (c >= 'A' && c <= 'Z') continue;
        if (c == ' '
                || c == '$'
                || c == '%'
                || c == '*'
                || c == '+'
                || c == '-'
                || c == '.'
                || c == '/'
                || c == ':')
            continue;
        return false;
    }
    return true;
}

/**
 * Allocate a qrcode
 * @param version qrcode version
 * @returns an allocated QRCode
 */
static QRCode* qrcode_alloc(uint8_t version) {
    QRCode* qrcode = malloc(sizeof(QRCode));
    qrcode->modules = malloc(qrcode_getBufferSize(version));
    return qrcode;
}

/**
 * Free a QRCode
 * @param qrcode The QRCode to free
 */
static void qrcode_free(QRCode* qrcode) {
    furi_assert(qrcode);
    free(qrcode->modules);
    free(qrcode);
}

/**
 * Rebuild the qrcode. Assumes that instance->message is the message to encode,
 * that the mutex has been acquired, and the specified version/ecc will be
 * sufficiently large enough to encode the full message. It is also assumed
 * that the old qrcode will be free'd by the caller.
 * @param instance The qrcode app instance
 * @param version The qrcode version to use
 * @param ecc The qrcode ECC level to use
 * @returns true if the qrcode was successfully created
 */
static bool rebuild_qrcode(QRCodeApp* instance, uint8_t version, uint8_t ecc) {
    furi_assert(instance);
    furi_assert(instance->message);

    const char* cstr = furi_string_get_cstr(instance->message);
    uint16_t len = strlen(cstr);
    instance->qrcode = qrcode_alloc(version);

    int8_t res = qrcode_initBytes(instance->qrcode, instance->qrcode->modules, version, ecc, (uint8_t*)cstr, len);
    if (res != 0) {
        FURI_LOG_E(TAG, "Could not create qrcode");

        qrcode_free(instance->qrcode);
        instance->qrcode = NULL;

        return false;
    }
    return true;
}

/**
 * Load a qrcode from a string
 * @param instance The qrcode app instance
 * @param str The message to encode as a qrcode
 * @returns true if the string was successfully loaded
 */
static bool qrcode_load_string(QRCodeApp* instance, FuriString* str) {
    furi_assert(instance);
    furi_assert(str);

    furi_check(furi_mutex_acquire(instance->mutex, FuriWaitForever) == FuriStatusOk);
    if (instance->message) {
        furi_string_free(instance->message);
        instance->message = NULL;
    }
    if (instance->qrcode) {
        qrcode_free(instance->qrcode);
        instance->qrcode = NULL;
    }
    instance->too_long = false;
    instance->show_stats = false;
    instance->selected_idx = 0;
    instance->edit = false;

    bool result = false;
    do {
        const char* cstr = furi_string_get_cstr(str);
        uint16_t len = strlen(cstr);

        instance->message = furi_string_alloc_set(str);
        if (!instance->message) {
            FURI_LOG_E(TAG, "Could not allocate message");
            break;
        }

        // figure out the qrcode "mode"
        uint8_t mode = MODE_BYTE;
        if      (is_numeric(cstr, len))      mode = MODE_NUMERIC;
        else if (is_alphanumeric(cstr, len)) mode = MODE_ALPHANUMERIC;

        // Figure out the smallest qrcode version that'll fit all of the data -
        // we prefer the smallest version to maximize the pixel size of each
        // module to improve reader performance. Here, version is the 0-based
        // index. The qrcode_initBytes function will want a 1-based version
        // number, so we'll add one later.
        uint8_t ecc = ECC_LOW;
        uint8_t version = 0;
        while (version < MAX_QRCODE_VERSION && MAX_LENGTH[mode][ecc][version] < len) {
            version++;
        }

        if (version == MAX_QRCODE_VERSION) {
            instance->too_long = true;
            break;
        }

        // Figure out the maximum ECC we can use. I shouldn't need to
        // bounds-check ecc in this loop because I already know from the loop
        // above that ECC_LOW (0) works... don't forget to add one to that
        // version number...
        ecc = ECC_HIGH;
        while (MAX_LENGTH[mode][ecc][version] < len) {
            ecc--;
        }
        version++;

        // Build the qrcode
        if (!rebuild_qrcode(instance, version, ecc)) {
            furi_string_free(instance->message);
            instance->message = NULL;
            break;
        }

        instance->min_version = instance->set_version = version;
        instance->max_ecc_at_min_version = instance->set_ecc = ecc;
        result = true;
    } while (false);

    instance->loading = false;

    furi_mutex_release(instance->mutex);

    return result;
}

/**
 * Load a qrcode from a file
 * @param instance The qrcode app instance
 * @param file_path Path to the file to read
 * @returns true if the file was successfully loaded
 */
static bool qrcode_load_file(QRCodeApp* instance, const char* file_path) {
    furi_assert(instance);
    furi_assert(file_path);

    FuriString* temp_str = furi_string_alloc();
    bool result = false;

    Storage* storage = furi_record_open(RECORD_STORAGE);
    FlipperFormat* file = flipper_format_file_alloc(storage);

    do {
        if (!flipper_format_file_open_existing(file, file_path)) break;

        uint32_t version = 0;
        if (!flipper_format_read_header(file, temp_str, &version)) break;
        if (furi_string_cmp_str(temp_str, QRCODE_FILETYPE)
                || version != QRCODE_FILE_VERSION) {
            FURI_LOG_E(TAG, "Incorrect file format or version");
            break;
        }

        if (!flipper_format_read_string(file, "Message", temp_str)) {
            FURI_LOG_E(TAG, "Message is missing");
            break;
        }

        if (!qrcode_load_string(instance, temp_str)) {
            break;
        }

        result = true;
    } while (false);

    furi_record_close(RECORD_STORAGE);
    flipper_format_free(file);
    furi_string_free(temp_str);

    return result;
}

/**
 * Allocate the qrcode app
 * @returns a qrcode app instance
 */
static QRCodeApp* qrcode_app_alloc() {
    QRCodeApp* instance = malloc(sizeof(QRCodeApp));

    instance->input_queue = furi_message_queue_alloc(8, sizeof(InputEvent));

    instance->view_port = view_port_alloc();
    view_port_draw_callback_set(instance->view_port, render_callback, instance);
    view_port_input_callback_set(instance->view_port, input_callback, instance);

    instance->gui = furi_record_open(RECORD_GUI);
    gui_add_view_port(instance->gui, instance->view_port, GuiLayerFullscreen);

    instance->mutex = furi_mutex_alloc(FuriMutexTypeNormal);

    instance->message = NULL;
    instance->qrcode = NULL;
    instance->loading = true;
    instance->too_long = false;
    instance->show_stats = false;
    instance->selected_idx = 0;
    instance->edit = false;

    return instance;
}

/**
 * Free the qrcode app
 * @param qrcode_app The app to free
 */
static void qrcode_app_free(QRCodeApp* instance) {
    if (instance->message) furi_string_free(instance->message);
    if (instance->qrcode) qrcode_free(instance->qrcode);

    gui_remove_view_port(instance->gui, instance->view_port);
    furi_record_close(RECORD_GUI);

    view_port_free(instance->view_port);

    furi_message_queue_free(instance->input_queue);

    furi_mutex_free(instance->mutex);

    free(instance);
}

/** App entrypoint */
int32_t qrcode_app(void* p) {
    QRCodeApp* instance = qrcode_app_alloc();
    FuriString* file_path = furi_string_alloc();

    do {
        if (p && strlen(p)) {
            furi_string_set(file_path, (const char*)p);
        } else {
            furi_string_set(file_path, QRCODE_FOLDER);

            DialogsFileBrowserOptions browser_options;
            dialog_file_browser_set_basic_options(
                    &browser_options, QRCODE_EXTENSION, &I_qrcode_10px);
            browser_options.hide_ext = true;
            browser_options.base_path = QRCODE_FOLDER;

            DialogsApp* dialogs = furi_record_open(RECORD_DIALOGS);
            bool res = dialog_file_browser_show(dialogs, file_path, file_path, &browser_options);

            furi_record_close(RECORD_DIALOGS);
            if (!res) {
                FURI_LOG_E(TAG, "No file selected");
                break;
            }
        }

        if (!qrcode_load_file(instance, furi_string_get_cstr(file_path))) {
            FURI_LOG_E(TAG, "Unable to load file");
        }

        InputEvent input;
        while (furi_message_queue_get(instance->input_queue, &input, FuriWaitForever) == FuriStatusOk) {
            furi_check(furi_mutex_acquire(instance->mutex, FuriWaitForever) == FuriStatusOk);

            if (input.key == InputKeyBack) {
                if (instance->message) {
                    furi_string_free(instance->message);
                    instance->message = NULL;
                }
                if (instance->qrcode) {
                    qrcode_free(instance->qrcode);
                    instance->qrcode = NULL;
                }
                instance->loading = true;
                instance->edit = false;
                furi_mutex_release(instance->mutex);
                break;
            } else if (input.key == InputKeyRight) {
                instance->show_stats = true;
            } else if (input.key == InputKeyLeft) {
                instance->show_stats = false;
            } else if (instance->show_stats && !instance->loading && instance->qrcode) {
                if (input.key == InputKeyUp) {
                    if (!instance->edit) {
                        instance->selected_idx = MAX(0, instance->selected_idx - 1);
                    } else {
                        if (instance->selected_idx == 0 && instance->set_version < MAX_QRCODE_VERSION) {
                            instance->set_version++;
                        } else if (instance->selected_idx == 1) {
                            uint8_t max_ecc = instance->set_version == instance->min_version ? instance->max_ecc_at_min_version : ECC_HIGH;
                            if (instance->set_ecc < max_ecc) {
                                instance->set_ecc++;
                            }
                        }
                    }
                } else if (input.key == InputKeyDown) {
                    if (!instance->edit) {
                        instance->selected_idx = MIN(1, instance->selected_idx + 1);
                    } else {
                        if (instance->selected_idx == 0 && instance->set_version > instance->min_version) {
                            instance->set_version--;
                            if (instance->set_version == instance->min_version) {
                                instance->set_ecc = MAX(instance->set_ecc, instance->max_ecc_at_min_version);
                            }
                        } else if (instance->selected_idx == 1 && instance->set_ecc > 0) {
                            instance->set_ecc--;
                        }
                    }
                } else if (input.key == InputKeyOk) {
                    if (instance->edit && (instance->set_version != instance->qrcode->version || instance->set_ecc != instance->qrcode->ecc)) {
                        QRCode* qrcode = instance->qrcode;
                        instance->loading = true;

                        if (rebuild_qrcode(instance, instance->set_version, instance->set_ecc)) {
                            qrcode_free(qrcode);
                        } else {
                            FURI_LOG_E(TAG, "Could not rebuild qrcode");
                            instance->qrcode = qrcode;
                            instance->set_version = qrcode->version;
                            instance->set_ecc = qrcode->ecc;
                        }

                        instance->loading = false;
                    }
                    instance->edit = !instance->edit;
                }
            }

            furi_mutex_release(instance->mutex);
            view_port_update(instance->view_port);
        }

        if (p && strlen(p)) {
            // if started with an arg, exit instead
            // of looping back to the browser
            break;
        }
    } while (true);

    furi_string_free(file_path);
    qrcode_app_free(instance);

    return 0;
}