/*

 * This file is part of mpv.

 *

 * mpv is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * mpv is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with mpv.  If not, see <http://www.gnu.org/licenses/>.

 */

#include <string.h>

#include <math.h>

#include "mpv_talloc.h"

#include "config.h"

#include "stream/stream.h"

#include "common/common.h"

#include "misc/bstr.h"

#include "misc/hash.h"

#include "misc/io_utils.h"

#include "common/msg.h"

#include "options/m_option.h"

#include "options/path.h"

#include "video/csputils.h"

#include "lcms.h"

#include "osdep/io.h"

#if HAVE_LCMS2

#include <lcms2.h>

#include <libavutil/sha.h>

#include <libavutil/mem.h>

struct gl_lcms {

    void *icc_data;

    size_t icc_size;

    struct AVBufferRef *vid_profile;

    char *current_profile;

    bool using_memory_profile;

    bool changed;

    enum pl_color_primaries current_prim;

    enum pl_color_transfer current_trc;

    struct mp_log *log;

    struct mpv_global *global;

    struct mp_icc_opts *opts;

};

static void lcms2_error_handler(cmsContext ctx, cmsUInt32Number code,

                                const char *msg)

{

    struct gl_lcms *p = cmsGetContextUserData(ctx);

    MP_ERR(p, "lcms2: %s\n", msg);

}

static void load_profile(struct gl_lcms *p)

{

    talloc_free(p->icc_data);

    p->icc_data = NULL;

    p->icc_size = 0;

    p->using_memory_profile = false;

    talloc_free(p->current_profile);

    p->current_profile = NULL;

    if (!p->opts->profile || !p->opts->profile[0])

        return;

    char *fname = mp_get_user_path(NULL, p->global, p->opts->profile);

    MP_VERBOSE(p, "Opening ICC profile '%s'\n", fname);

    struct bstr iccdata = stream_read_file(fname, p, p->global,

                                           100000000); // 100 MB

    talloc_free(fname);

    if (!iccdata.len)

        return;

    talloc_free(p->icc_data);

    p->icc_data = iccdata.start;

    p->icc_size = iccdata.len;

    p->current_profile = talloc_strdup(p, p->opts->profile);

}

static void gl_lcms_destructor(void *ptr)

{

    struct gl_lcms *p = ptr;

    av_buffer_unref(&p->vid_profile);

}

struct gl_lcms *gl_lcms_init(void *talloc_ctx, struct mp_log *log,

                             struct mpv_global *global,

                             struct mp_icc_opts *opts)

{

    struct gl_lcms *p = talloc_ptrtype(talloc_ctx, p);

    talloc_set_destructor(p, gl_lcms_destructor);

    *p = (struct gl_lcms) {

        .global = global,

        .log = log,

        .opts = opts,

    };

    gl_lcms_update_options(p);

    return p;

}

void gl_lcms_update_options(struct gl_lcms *p)

{

    if ((p->using_memory_profile && !p->opts->profile_auto) ||

        !bstr_equals(bstr0(p->opts->profile), bstr0(p->current_profile)))

    {

        load_profile(p);

    }

    p->changed = true; // probably

}

// Warning: profile.start must point to a ta allocation, and the function

//          takes over ownership.

// Returns whether the internal profile was changed.

bool gl_lcms_set_memory_profile(struct gl_lcms *p, bstr profile)

{

    if (!p->opts->profile_auto || (p->opts->profile && p->opts->profile[0])) {

        talloc_free(profile.start);

        return false;

    }

    if (p->using_memory_profile &&

        p->icc_data && profile.start &&

        profile.len == p->icc_size &&

        memcmp(profile.start, p->icc_data, p->icc_size) == 0)

    {

        talloc_free(profile.start);

        return false;

    }

    p->changed = true;

    p->using_memory_profile = true;

    talloc_free(p->icc_data);

    p->icc_data = talloc_steal(p, profile.start);

    p->icc_size = profile.len;

    return true;

}

// Guards against NULL and uses bstr_equals to short-circuit some special cases

static bool vid_profile_eq(struct AVBufferRef *a, struct AVBufferRef *b)

{

    if (!a || !b)

        return a == b;

    return bstr_equals((struct bstr){ a->data, a->size },

                       (struct bstr){ b->data, b->size });

}

// Return whether the profile or config has changed since the last time it was

// retrieved. If it has changed, gl_lcms_get_lut3d() should be called.

bool gl_lcms_has_changed(struct gl_lcms *p, enum pl_color_primaries prim,

                         enum pl_color_transfer trc, struct AVBufferRef *vid_profile)

{

    if (p->changed || p->current_prim != prim || p->current_trc != trc)

        return true;

    return !vid_profile_eq(p->vid_profile, vid_profile);

}

// Whether a profile is set. (gl_lcms_get_lut3d() is expected to return a lut,

// but it could still fail due to runtime errors, such as invalid icc data.)

bool gl_lcms_has_profile(struct gl_lcms *p)

{

    return p->icc_size > 0;

}

static cmsHPROFILE get_vid_profile(struct gl_lcms *p, cmsContext cms,

                                   cmsHPROFILE disp_profile,

                                   enum pl_color_primaries prim, enum pl_color_transfer trc)

{

    if (p->opts->use_embedded && p->vid_profile) {

        // Try using the embedded ICC profile

        cmsHPROFILE prof = cmsOpenProfileFromMemTHR(cms, p->vid_profile->data,

                                                    p->vid_profile->size);

        if (prof) {

            MP_VERBOSE(p, "Successfully opened embedded ICC profile\n");

            return prof;

        }

        // Otherwise, warn the user and generate the profile as usual

        MP_WARN(p, "Video contained an invalid ICC profile! Ignoring...\n");

    }

    // The input profile for the transformation is dependent on the video

    // primaries and transfer characteristics

    const struct pl_raw_primaries *csp = pl_raw_primaries_get(prim);

    cmsCIExyY wp_xyY = {csp->white.x, csp->white.y, 1.0};

    cmsCIExyYTRIPLE prim_xyY = {

        .Red   = {csp->red.x,   csp->red.y,   1.0},

        .Green = {csp->green.x, csp->green.y, 1.0},

        .Blue  = {csp->blue.x,  csp->blue.y,  1.0},

    };

    cmsToneCurve *tonecurve[3] = {0};

    switch (trc) {

    case PL_COLOR_TRC_LINEAR:  tonecurve[0] = cmsBuildGamma(cms, 1.0); break;

    case PL_COLOR_TRC_GAMMA18: tonecurve[0] = cmsBuildGamma(cms, 1.8); break;

    case PL_COLOR_TRC_GAMMA20: tonecurve[0] = cmsBuildGamma(cms, 2.0); break;

    case PL_COLOR_TRC_GAMMA22: tonecurve[0] = cmsBuildGamma(cms, 2.2); break;

    case PL_COLOR_TRC_GAMMA24: tonecurve[0] = cmsBuildGamma(cms, 2.4); break;

    case PL_COLOR_TRC_GAMMA26: tonecurve[0] = cmsBuildGamma(cms, 2.6); break;

    case PL_COLOR_TRC_GAMMA28: tonecurve[0] = cmsBuildGamma(cms, 2.8); break;

    case PL_COLOR_TRC_ST428:

        tonecurve[0] = cmsBuildParametricToneCurve(cms, 2,

                (double[3]){2.6, pow(52.37/48.0, 1/2.6), 0.0});

        break;

    case PL_COLOR_TRC_SRGB:

        // Values copied from Little-CMS

        tonecurve[0] = cmsBuildParametricToneCurve(cms, 4,

                (double[5]){2.40, 1/1.055, 0.055/1.055, 1/12.92, 0.04045});

        break;

    case PL_COLOR_TRC_PRO_PHOTO:

        tonecurve[0] = cmsBuildParametricToneCurve(cms, 4,

                (double[5]){1.8, 1.0, 0.0, 1/16.0, 0.03125});

        break;

    case PL_COLOR_TRC_BT_1886: {

        double src_black[3];

        if (p->opts->contrast < 0) {

            // User requested infinite contrast, return 2.4 profile

            tonecurve[0] = cmsBuildGamma(cms, 2.4);

            break;

        } else if (p->opts->contrast > 0) {

            MP_VERBOSE(p, "Using specified contrast: %d\n", p->opts->contrast);

            for (int i = 0; i < 3; i++)

                src_black[i] = 1.0 / p->opts->contrast;

        } else {

            // To build an appropriate BT.1886 transformation we need access to

            // the display's black point, so we use LittleCMS' detection

            // function. Relative colorimetric is used since we want to

            // approximate the BT.1886 to the target device's actual black

            // point even in e.g. perceptual mode

            const int intent = PL_INTENT_RELATIVE_COLORIMETRIC;

            cmsCIEXYZ bp_XYZ;

            if (!cmsDetectBlackPoint(&bp_XYZ, disp_profile, intent, 0))

                return false;

            // Map this XYZ value back into the (linear) source space

            cmsHPROFILE rev_profile;

            cmsToneCurve *linear = cmsBuildGamma(cms, 1.0);

            rev_profile = cmsCreateRGBProfileTHR(cms, &wp_xyY, &prim_xyY,

                    (cmsToneCurve*[3]){linear, linear, linear});

            cmsHPROFILE xyz_profile = cmsCreateXYZProfile();

            cmsHTRANSFORM xyz2src = cmsCreateTransformTHR(cms,

                    xyz_profile, TYPE_XYZ_DBL, rev_profile, TYPE_RGB_DBL,

                    intent, cmsFLAGS_NOCACHE | cmsFLAGS_NOOPTIMIZE);

            cmsFreeToneCurve(linear);

            cmsCloseProfile(rev_profile);

            cmsCloseProfile(xyz_profile);

            if (!xyz2src)

                return false;

            cmsDoTransform(xyz2src, &bp_XYZ, src_black, 1);

            cmsDeleteTransform(xyz2src);

            double contrast = 3.0 / (src_black[0] + src_black[1] + src_black[2]);

            MP_VERBOSE(p, "Detected ICC profile contrast: %f\n", contrast);

        }

        // Build the parametric BT.1886 transfer curve, one per channel

        for (int i = 0; i < 3; i++) {

            const double gamma = 2.40;

            double binv = pow(src_black[i], 1.0/gamma);

            tonecurve[i] = cmsBuildParametricToneCurve(cms, 6,

                    (double[4]){gamma, 1.0 - binv, binv, 0.0});

        }

        break;

    }

    default:

        abort();

    }

    if (!tonecurve[0])

        return false;

    if (!tonecurve[1]) tonecurve[1] = tonecurve[0];

    if (!tonecurve[2]) tonecurve[2] = tonecurve[0];

    cmsHPROFILE *vid_profile = cmsCreateRGBProfileTHR(cms, &wp_xyY, &prim_xyY,

                                                      tonecurve);

    if (tonecurve[2] != tonecurve[0]) cmsFreeToneCurve(tonecurve[2]);

    if (tonecurve[1] != tonecurve[0]) cmsFreeToneCurve(tonecurve[1]);

    cmsFreeToneCurve(tonecurve[0]);

    return vid_profile;

}

bool gl_lcms_get_lut3d(struct gl_lcms *p, struct lut3d **result_lut3d,

                       enum pl_color_primaries prim, enum pl_color_transfer trc,

                       struct AVBufferRef *vid_profile)

{

    int s_r, s_g, s_b;

    bool result = false;

    p->changed = false;

    p->current_prim = prim;

    p->current_trc = trc;

    // We need to hold on to a reference to the video's ICC profile for as long

    // as we still need to perform equality checking, so generate a new

    // reference here

    av_buffer_unref(&p->vid_profile);

    if (vid_profile) {

        MP_VERBOSE(p, "Got an embedded ICC profile.\n");

        p->vid_profile = av_buffer_ref(vid_profile);

        MP_HANDLE_OOM(p->vid_profile);

    }

    if (!gl_parse_3dlut_size(p->opts->size_str, &s_r, &s_g, &s_b))

        return false;

    if (!gl_lcms_has_profile(p))

        return false;

    // For simplicity, default to 65x65x65, which is large enough to cover

    // typical profiles with good accuracy while not being too wasteful

    s_r = s_r ? s_r : 65;

    s_g = s_g ? s_g : 65;

    s_b = s_b ? s_b : 65;

    void *tmp = talloc_new(NULL);

    uint16_t *output = talloc_array(tmp, uint16_t, s_r * s_g * s_b * 4);

    struct lut3d *lut = NULL;

    cmsContext cms = NULL;

    char *cache_file = NULL;

    if (p->opts->cache) {

        // Gamma is included in the header to help uniquely identify it,

        // because we may change the parameter in the future or make it

        // customizable, same for the primaries.

        bstr cache_info = {0};

        bstr_xappend_asprintf(tmp, &cache_info,

            "ver=1.4, intent=%d, size=%dx%dx%d, prim=%d, trc=%d, "

            "contrast=%d\n",

            p->opts->intent, s_r, s_g, s_b, prim, trc, p->opts->contrast);

        if (vid_profile)

            bstr_xappend(tmp, &cache_info, (bstr){vid_profile->data, vid_profile->size});

        bstr_xappend(tmp, &cache_info, (bstr){p->icc_data, p->icc_size});

        bstr hashstr = mp_hash_to_bstr(tmp, cache_info.start, cache_info.len, "SHA256");

        char *cache_dir = p->opts->cache_dir;

        if (cache_dir && cache_dir[0]) {

            cache_dir = mp_get_user_path(tmp, p->global, cache_dir);

        } else {

            cache_dir = mp_find_user_file(tmp, p->global, "cache", "");

        }

        if (cache_dir && cache_dir[0]) {

            cache_file = mp_path_join_bstr(tmp, bstr0(cache_dir), hashstr);

            mp_mkdirp(cache_dir);

        }

    }

    // check cache

    if (cache_file && stat(cache_file, &(struct stat){0}) == 0) {

        MP_VERBOSE(p, "Opening 3D LUT cache in file '%s'.\n", cache_file);

        struct bstr cachedata = stream_read_file(cache_file, tmp, p->global,

                                                 1000000000); // 1 GB

        if (cachedata.len == talloc_get_size(output)) {

            memcpy(output, cachedata.start, cachedata.len);

            goto done;

        } else {

            MP_WARN(p, "3D LUT cache invalid!\n");

        }

    }

    cms = cmsCreateContext(NULL, p);

    if (!cms)

        goto error_exit;

    cmsSetLogErrorHandlerTHR(cms, lcms2_error_handler);

    cmsHPROFILE profile =

        cmsOpenProfileFromMemTHR(cms, p->icc_data, p->icc_size);

    if (!profile)

        goto error_exit;

    cmsHPROFILE vid_hprofile = get_vid_profile(p, cms, profile, prim, trc);

    if (!vid_hprofile) {

        cmsCloseProfile(profile);

        goto error_exit;

    }

    cmsHTRANSFORM trafo = cmsCreateTransformTHR(cms, vid_hprofile, TYPE_RGB_16,

                                                profile, TYPE_RGBA_16,

                                                p->opts->intent,

                                                cmsFLAGS_NOCACHE |

                                                cmsFLAGS_NOOPTIMIZE |

                                                cmsFLAGS_BLACKPOINTCOMPENSATION);

    cmsCloseProfile(profile);

    cmsCloseProfile(vid_hprofile);

    if (!trafo)

        goto error_exit;

    // transform a (s_r)x(s_g)x(s_b) cube, with 3 components per channel

    uint16_t *input = talloc_array(tmp, uint16_t, s_r * 3);

    for (int b = 0; b < s_b; b++) {

        for (int g = 0; g < s_g; g++) {

            for (int r = 0; r < s_r; r++) {

                input[r * 3 + 0] = r * 65535 / (s_r - 1);

                input[r * 3 + 1] = g * 65535 / (s_g - 1);

                input[r * 3 + 2] = b * 65535 / (s_b - 1);

            }

            size_t base = (b * s_r * s_g + g * s_r) * 4;

            cmsDoTransform(trafo, input, output + base, s_r);

        }

    }

    cmsDeleteTransform(trafo);

    if (cache_file)

        mp_save_to_file(cache_file, output, talloc_get_size(output));

done: ;

    lut = talloc_ptrtype(NULL, lut);

    *lut = (struct lut3d) {

        .data = talloc_steal(lut, output),

        .size = {s_r, s_g, s_b},

    };

    *result_lut3d = lut;

    result = true;

error_exit:

    if (cms)

        cmsDeleteContext(cms);

    if (!lut)

        MP_FATAL(p, "Error loading ICC profile.\n");

    talloc_free(tmp);

    return result;

}

#else /* HAVE_LCMS2 */

struct gl_lcms *gl_lcms_init(void *talloc_ctx, struct mp_log *log,

                             struct mpv_global *global,

                             struct mp_icc_opts *opts)

{

    return (struct gl_lcms *) talloc_new(talloc_ctx);

}

void gl_lcms_update_options(struct gl_lcms *p) { }

bool gl_lcms_set_memory_profile(struct gl_lcms *p, bstr profile) {return false;}

bool gl_lcms_has_changed(struct gl_lcms *p, enum pl_color_primaries prim,

                         enum pl_color_transfer trc, struct AVBufferRef *vid_profile)

{

    return false;

}

bool gl_lcms_has_profile(struct gl_lcms *p)

{

    return false;

}

bool gl_lcms_get_lut3d(struct gl_lcms *p, struct lut3d **result_lut3d,

                       enum pl_color_primaries prim, enum pl_color_transfer trc,

                       struct AVBufferRef *vid_profile)

{

    return false;

}

#endif

static inline OPT_STRING_VALIDATE_FUNC(validate_3dlut_size_opt)

{

    int p1, p2, p3;

    return gl_parse_3dlut_size(*value, &p1, &p2, &p3) ? 0 : M_OPT_INVALID;

}

#define OPT_BASE_STRUCT struct mp_icc_opts

const struct m_sub_options mp_icc_conf = {

    .opts = (const m_option_t[]) {

        {"use-embedded-icc-profile", OPT_BOOL(use_embedded)},

        {"icc-profile", OPT_STRING(profile), .flags = M_OPT_FILE},

        {"icc-profile-auto", OPT_BOOL(profile_auto)},

        {"icc-cache", OPT_BOOL(cache)},

        {"icc-cache-dir", OPT_STRING(cache_dir), .flags = M_OPT_FILE},

        {"icc-intent", OPT_INT(intent)},

        {"icc-force-contrast", OPT_CHOICE(contrast, {"no", 0}, {"inf", -1}),

            M_RANGE(0, 1000000)},

        {"icc-3dlut-size", OPT_STRING_VALIDATE(size_str, validate_3dlut_size_opt)},

        {"icc-use-luma", OPT_BOOL(icc_use_luma)},

        {0}

    },

    .size = sizeof(struct mp_icc_opts),

    .defaults = &(const struct mp_icc_opts) {

        .size_str = "auto",

        .intent = PL_INTENT_RELATIVE_COLORIMETRIC,

        .use_embedded = true,

        .cache = true,

    },

};