#include "qt_mainwindow.hpp"
#include <QMessageBox>
#include <QWindow>
#include <QCoreApplication>

extern MainWindow* main_window;

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <stdint.h>
extern "C"
{
#include <86box/86box.h>
#include <86box/ini.h>
#include <86box/config.h>
#include <86box/qt-glslp-parser.h>
#include <86box/path.h>
#include <86box/plat.h>

extern void startblit();
extern void endblit();
extern ssize_t local_getline(char **buf, size_t *bufsiz, FILE *fp);
extern char* trim(char* str);
}

#define safe_strncpy(a, b, n)                                                                                                    \
        do {                                                                                                                     \
                strncpy((a), (b), (n)-1);                                                                                        \
                (a)[(n)-1] = 0;                                                                                                  \
        } while (0)



static inline void *wx_config_load(const char *path) { ini_t ini = ini_read(path); if (ini) ini_strip_quotes(ini); return (void*)ini; }

static inline int wx_config_get_string(void *config, const char *name, char *dst, int size, const char *defVal) {
    int res = ini_has_entry(ini_find_or_create_section((ini_t)config, ""), name);
    char* str = ini_get_string((ini_t)config, "", name, (char*)defVal);
    if (size == 0)
        return res;
    if (str != NULL)
        strncpy(dst, str, size - 1);
    else
        dst[0] = 0;
    return res;
}

static inline int wx_config_get_int(void *config, const char *name, int *dst, int defVal) {
    int res = ini_has_entry(ini_find_or_create_section((ini_t)config, ""), name);
    *dst = ini_get_int((ini_t)config, "", name, defVal);
    return res;
}

static inline int wx_config_get_float(void *config, const char *name, float *dst, float defVal) {
    int res = ini_has_entry(ini_find_or_create_section((ini_t)config, ""), name);
    *dst = (float)ini_get_double((ini_t)config, "", name, defVal);
    return res;
}

static inline int wx_config_get_bool(void *config, const char *name, int *dst, int defVal) {
    int res = ini_has_entry(ini_find_or_create_section((ini_t)config, ""), name);
    *dst = !!ini_get_int((ini_t)config, "", name, defVal);
    return res;
}

static inline int wx_config_has_entry(void *config, const char *name) { return ini_has_entry(ini_find_or_create_section((ini_t)config, ""), name); }
static inline void wx_config_free(void *config) { ini_close(config); };

static int endswith(const char *str, const char *ext) {
        const char *p;
        int elen = strlen(ext);
        int slen = strlen(str);
        if (slen >= elen) {
                p = &str[slen - elen];
                for (int i = 0; i < elen; ++i) {
                        if (tolower(p[i]) != tolower(ext[i]))
                                return 0;
                }
                return 1;
        }
        return 0;
}

static int
glsl_detect_bom(const char *fn)
{
    FILE         *fp;
    unsigned char bom[4] = { 0, 0, 0, 0 };

    fp = plat_fopen(fn, "rb");
    if (fp == NULL)
        return 0;
    (void) !fread(bom, 1, 3, fp);
    if (bom[0] == 0xEF && bom[1] == 0xBB && bom[2] == 0xBF) {
        fclose(fp);
        return 1;
    }
    fclose(fp);
    return 0;
}

static char *load_file(const char *fn) {
        int bom = glsl_detect_bom(fn);
        FILE *fp = plat_fopen(fn, "rb");
        if (!fp)
                return 0;
        fseek(fp, 0, SEEK_END);
        long fsize = ftell(fp);
        fseek(fp, 0, SEEK_SET);

        if (bom) {
                fsize -= 3;
                fseek(fp, 3, SEEK_SET);
        }

        char *data = (char*)malloc(fsize + 1);

        size_t read_bytes = fread(data, fsize, 1, fp);
        if (read_bytes != 1) {
            fclose(fp);
            free(data);
            return nullptr;
        } else {
            fclose(fp);

            data[fsize] = 0;

            return data;
        }
}

static void strip_lines(const char *program, const char *starts_with) {
        /* strip parameters */
        char *ptr = (char *) strstr(program, starts_with);
        while (ptr != nullptr) {
                while (*ptr != '\n' && *ptr != '\0')
                        *ptr++ = ' ';
                ptr = (char *) strstr(program, starts_with);
        }
}

static void strip_parameters(const char *program) {
        /* strip parameters */
        strip_lines(program, "#pragma parameter");
}

static void strip_defines(const char *program) {
        /* strip texture define */
        strip_lines(program, "#define texture");
}

static int has_parameter(glslp_t *glsl, char *id) {
        for (int i = 0; i < glsl->num_parameters; ++i)
                if (!strcmp(glsl->parameters[i].id, id))
                        return 1;
        return 0;
}

static int get_parameters(glslp_t *glsl) {
        struct parameter p;
        for (int i = 0; i < glsl->num_shaders; ++i) {
                size_t size = 0;
                char* line = NULL;
                struct shader *shader = &glsl->shaders[i];
                int bom = glsl_detect_bom(shader->shader_fn);
                FILE *f = plat_fopen(shader->shader_fn, "rb");
                if (!f)
                        return 0;
                if (bom) {
                        fseek(f, 3, SEEK_SET);
                }
                while (local_getline(&line, &size, f) != -1 && glsl->num_parameters < MAX_PARAMETERS) {
                        line[strcspn(line, "\r\n")] = '\0';
                        trim(line);
                        int num = sscanf(line, "#pragma parameter %63s \"%63[^\"]\" %f %f %f %f", p.id, p.description,
                                         &p.default_value, &p.min, &p.max, &p.step);
                        if (num < 5)
                                continue;
                        p.id[63] = 0;
                        p.description[63] = 0;

                        if (num == 5)
                                p.step = 0.1f * (p.max - p.min);

                        p.value = p.default_value;

                        if (!has_parameter(glsl, p.id)) {
                                memcpy(&glsl->parameters[glsl->num_parameters++], &p, sizeof(struct parameter));
                                pclog("Read parameter: %s (%s) %f, %f -> %f (%f)\n", p.id, p.description, p.default_value, p.min,
                                      p.max, p.step);
                        }
                }

                fclose(f);
        }

        return 1;
}

static struct parameter *get_parameter(glslp_t *glslp, const char *id) {
        for (int i = 0; i < glslp->num_parameters; ++i) {
                if (!strcmp(glslp->parameters[i].id, id)) {
                        return &glslp->parameters[i];
                }
        }
        return 0;
}

static glslp_t *glsl_parse(const char *f) {
        glslp_t *glslp = (glslp_t*) calloc(1, sizeof(glslp_t));
        glslp->num_shaders = 1;
        struct shader *shader = &glslp->shaders[0];
        strcpy(shader->shader_fn, f);
        shader->shader_program = load_file(f);
        if (!shader->shader_program) {
                QMessageBox::critical((QWidget *) qApp->findChild<QWindow *>(), QObject::tr("GLSL error"), QObject::tr("Could not load shader: %1").arg(shader->shader_fn));
                //wx_simple_messagebox("GLSL error", "Could not load shader %s\n", shader->shader_fn);
                glslp_free(glslp);
                return 0;
        }
        strip_parameters(shader->shader_program);
        strip_defines(shader->shader_program);
        shader->scale_x = shader->scale_y = 1.0f;
        strcpy(shader->scale_type_x, "source");
        strcpy(shader->scale_type_y, "source");
        get_parameters(glslp);
        return glslp;
}

extern "C" {

void get_glslp_name(const char *f, char *s, int size) { safe_strncpy(s, path_get_filename((char *)f), size); }

glslp_t *glslp_parse(const char *f) {
        int j;
        int len;
        int sublen;
        char s[2049], t[2049], z[2076];

        memset(s, 0, sizeof(s));
        if (endswith(f, ".glsl"))
                return glsl_parse(f);

        void *cfg = wx_config_load(f);

        if (!cfg) {
                fprintf(stderr, "GLSLP Error: Could not load GLSLP-file %s\n", f);
                return 0;
        }

        glslp_t *glslp = (glslp_t*) calloc(1, sizeof(glslp_t));

        get_glslp_name(f, glslp->name, sizeof(glslp->name));

        wx_config_get_int(cfg, "shaders", &glslp->num_shaders, 0);

        wx_config_get_bool(cfg, "filter_linear0", &glslp->input_filter_linear, -1);

        for (int i = 0; i < glslp->num_shaders; ++i) {
                struct shader *shader = &glslp->shaders[i];

                snprintf(s, sizeof(s) - 1, "shader%d", i);
                if (!wx_config_get_string(cfg, s, t, sizeof(t), 0)) {
                        /* shader doesn't exist, lets break here */
                        glslp->num_shaders = i;
                        break;
                }
                strcpy(s, f);
                *path_get_filename(s) = 0;

                size_t max_len = sizeof(shader->shader_fn);
                size_t s_len = strlen(s);

                if (s_len >= max_len) {
                    // s alone fills or overflows the buffer, truncate and null-terminate
                    size_t copy_len = max_len - 1 < s_len ? max_len - 1 : s_len;
                    memcpy(shader->shader_fn, s, copy_len);
                    shader->shader_fn[copy_len] = '\0';
                } else {
                    // Copy s fully
                    memcpy(shader->shader_fn, s, s_len);
                    // Copy as much of t as fits after s
                    size_t avail = max_len - 1 - s_len; // space left for t + null terminator
                    // Copy as much of t as fits into the remaining space
                    memcpy(shader->shader_fn + s_len, t, avail);
                    // Null-terminate
                    shader->shader_fn[s_len + avail] = '\0';
                }

                shader->shader_program = load_file(shader->shader_fn);
                if (!shader->shader_program) {
                    fprintf(stderr, "GLSLP Error: Could not load shader %s\n", shader->shader_fn);
                    glslp_free(glslp);
                    return 0;
                }
                strip_parameters(shader->shader_program);
                strip_defines(shader->shader_program);

                snprintf(s, sizeof(s) - 1, "alias%d", i);
                wx_config_get_string(cfg, s, shader->alias, sizeof(shader->alias), 0);

                snprintf(s, sizeof(s) - 1, "filter_linear%d", i + 1);
                wx_config_get_bool(cfg, s, &shader->filter_linear, 0);

                snprintf(s, sizeof(s) - 1, "wrap_mode%d", i);
                wx_config_get_string(cfg, s, shader->wrap_mode, sizeof(shader->wrap_mode), 0);

                snprintf(s, sizeof(s) - 1, "float_framebuffer%d", i);
                wx_config_get_bool(cfg, s, &shader->float_framebuffer, 0);
                snprintf(s, sizeof(s) - 1, "srgb_framebuffer%d", i);
                wx_config_get_bool(cfg, s, &shader->srgb_framebuffer, 0);

                snprintf(s, sizeof(s) - 1, "mipmap_input%d", i);
                wx_config_get_bool(cfg, s, &shader->mipmap_input, 0);

                strcpy(shader->scale_type_x, "source");
                snprintf(s, sizeof(s) - 1, "scale_type_x%d", i);
                wx_config_get_string(cfg, s, shader->scale_type_x, sizeof(shader->scale_type_x), 0);
                strcpy(shader->scale_type_y, "source");
                snprintf(s, sizeof(s) - 1, "scale_type_y%d", i);
                wx_config_get_string(cfg, s, shader->scale_type_y, sizeof(shader->scale_type_y), 0);
                snprintf(s, sizeof(s) - 1, "scale_type%d", i);
                if (wx_config_has_entry(cfg, s)) {
                        wx_config_get_string(cfg, s, shader->scale_type_x, sizeof(shader->scale_type_x), 0);
                        wx_config_get_string(cfg, s, shader->scale_type_y, sizeof(shader->scale_type_y), 0);
                }

                snprintf(s, sizeof(s) - 1, "scale_x%d", i);
                wx_config_get_float(cfg, s, &shader->scale_x, 1.0f);
                snprintf(s, sizeof(s) - 1, "scale_y%d", i);
                wx_config_get_float(cfg, s, &shader->scale_y, 1.0f);
                snprintf(s, sizeof(s) - 1, "scale%d", i);
                if (wx_config_has_entry(cfg, s)) {
                        wx_config_get_float(cfg, s, &shader->scale_x, 1.0f);
                        wx_config_get_float(cfg, s, &shader->scale_y, 1.0f);
                }

                snprintf(s, sizeof(s) - 1, "frame_count_mod%d", i);
                wx_config_get_int(cfg, s, &shader->frame_count_mod, 0);
        }

        /* textures */
        glslp->num_textures = 0;
        wx_config_get_string(cfg, "textures", t, sizeof(t), 0);

        len = strlen(t);
        j = 0;
        sublen = 0;
        for (int i = 0; i < len; ++i) {
                if (t[i] == ';' || i == len - 1) {
                        sublen = (i - j) + ((i == len - 1) ? 1 : 0) + 1;
                        safe_strncpy(s, t + j, sublen);
                        s[511 < sublen ? 511 : sublen] = 0;

                        if (s[strlen(s) - 1] == ';') s[strlen(s) - 1] = 0;

                        struct texture *tex = &glslp->textures[glslp->num_textures++];

                        strcpy(tex->name, s);
                        wx_config_get_string(cfg, s, tex->path, sizeof(tex->path), 0);

                        snprintf(z, sizeof(z) - 1, "%s_linear", s);
                        wx_config_get_bool(cfg, z, &tex->linear, 0);

                        snprintf(z, sizeof(z) - 1, "%s_mipmap", s);
                        wx_config_get_bool(cfg, z, &tex->mipmap, 0);

                        snprintf(z, sizeof(z) - 1, "%s_wrap_mode", s);
                        wx_config_get_string(cfg, z, tex->wrap_mode, sizeof(tex->wrap_mode), 0);

                        j = i + 1;
                }
        }

        /* parameters */
        get_parameters(glslp);

        wx_config_get_string(cfg, "parameters", t, sizeof(t), 0);

        len = strlen(t);
        j = 0;
        sublen = 0;
        for (int i = 0; i < len; ++i) {
                if (t[i] == ';' || i == len - 1) {
                        sublen = (i - j) + ((i == len - 1) ? 1 : 0) + 1;
                        safe_strncpy(s, t + j, sublen);
                        s[511 < sublen ? 511 : sublen] = 0;

                        struct parameter *p = get_parameter(glslp, s);

                        if (p)
                                wx_config_get_float(cfg, s, &p->default_value, 0);

                        j = i + 1;
                }
        }

        wx_config_free(cfg);

        return glslp;
}

void glslp_free(glslp_t *p) {
        for (int i = 0; i < p->num_shaders; ++i)
                if (p->shaders[i].shader_program)
                        free(p->shaders[i].shader_program);
        free(p);
}

void glslp_read_shader_config(glslp_t *shader) {
    char s[512];
    char *name = shader->name;
    snprintf(s, sizeof(s) -1, "GL3 Shaders - %s", name);
    for (int i = 0; i < shader->num_parameters; ++i) {
        struct parameter *param = &shader->parameters[i];
        param->value = config_get_double(s, param->id, param->default_value);
    }
}

void glslp_write_shader_config(glslp_t *shader) {
    char s[512];
    char *name = shader->name;

    startblit();
    snprintf(s, sizeof(s) - 1, "GL3 Shaders - %s", name);
    for (int i = 0; i < shader->num_parameters; ++i) {
        struct parameter *param = &shader->parameters[i];
        config_set_double(s, param->id, param->value);
    }
    endblit();
}

}
