#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <defocus/defocus.h>

int pinhole_fn(int argc, char **argv);
int thin_lense_fn(int argc, char **argv);

static const char *_model_names[] = {"pinhole", "thin_lense"};
typedef int (*model_fn)(int argc, char **argv);

static model_fn _model_fns[] = {
    pinhole_fn,
    thin_lense_fn,
};

void usage(const char *pname)
{
    printf("Usage: %s <model-name> [model parameters]\n", pname);
    printf("Available models:\n");
    for (int i = 0; i < DF_ARRAY_COUNT(_model_names); ++i) {
        printf(" %s\n", _model_names[i]);
    }
}

int main(int argc, char **argv)
{
    if (argc < 2) {
        fprintf(stderr, "Missing model name!\n");
        usage(argv[0]);
        return 1;
    }

    model_fn fn = NULL;
    const char *model = argv[1];
    for (int i = 0; i < DF_ARRAY_COUNT(_model_names); ++i) {
        if (strcmp(model, _model_names[i]) == 0) {
            fn = _model_fns[i];
            break;
        }
    }
    if (!fn) {
        fprintf(stderr, "Invalid model name!\n");
        usage(argv[0]);
        return 1;
    }

    return fn(argc - 2, &argv[2]);
}

int pinhole_fn(int argc, char **argv)
{
    const char *in_path = NULL;
    const char *out_path = "out.png";
    const char *focal_str = NULL;
    const char *in_z_str = NULL;
    const char *out_z_str = NULL;

    for (int i = 0; i < argc; ++i) {
        if ((strcmp(argv[i], "-i") == 0 || strcmp(argv[i], "--input") == 0) && i < argc - 1) {
            ++i;
            in_path = argv[i];
        } else if ((strcmp(argv[i], "-o") == 0 || strcmp(argv[i], "--output") == 0) && i < argc - 1) {
            ++i;
            out_path = argv[i];
        } else if ((strcmp(argv[i], "-f") == 0 || strcmp(argv[i], "--focal-length") == 0) && i < argc - 1) {
            ++i;
            focal_str = argv[i];
        } else if ((strcmp(argv[i], "-iz") == 0 || strcmp(argv[i], "--input-z") == 0) && i < argc - 1) {
            ++i;
            in_z_str = argv[i];
        } else if ((strcmp(argv[i], "-oz") == 0 || strcmp(argv[i], "--output-z") == 0) && i < argc - 1) {
            ++i;
            out_z_str = argv[i];
        } else {
            in_path = argv[i];
        }
    }

    if (!in_path || !focal_str || !in_z_str || !out_z_str) {
        fprintf(stderr, "Missing model parameters!\n");
        printf("Pinhole model parameters:\n");
        printf("  -i  | --input <path>\t\tPath to the input image.\n");
        printf("  -o  | --output <path>\t\tPath to the output image (Default: out.png).\n");
        printf("  -iz | --input-z <number>\t\tDistance to the input image plane.\n");
        printf("  -oz | --output-z <number>\t\tDistance to the output image plane.\n");
        printf("  -f  | --focal-length <number>\t\tThe focal length of the camera lens.\n");
        return 1;
    }

    float focal, in_z, out_z;
    focal = atof(focal_str);
    in_z = atof(in_z_str);
    out_z = atof(out_z_str);

    df_image *in_image, *out_image;

    int w, h;
    df_result res = df_load_image(in_path, &w, &h, &in_image);
    if (res != df_result_success) {
        fprintf(stderr, "Failed to load %s! (%d)\n", in_path, (int)res);
        return 1;
    }

    res = df_create_image(w, h, &out_image);
    if (res != df_result_success) {
        fprintf(stderr, "Failed to create output image (%d)\n", (int)res);
        df_release_image(in_image);
        return 1;
    }

    df_pinhole(in_image, focal, in_z, out_z, out_image);

    int error_code = 0;
    res = df_write_image(out_image, out_path);
    if (res != df_result_success) {
        fprintf(stderr, "Failed to write to output image %s (%d)\n", out_path, (int)res);
        error_code = 1;
    }

    df_release_image(in_image);
    df_release_image(out_image);

    return error_code;
}

int thin_lense_fn(int argc, char **argv)
{
    fprintf(stderr, "Not implemented yet");
    return 1;
}