/*  Copyright (C) 1996-1997  Id Software, Inc.

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program 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 General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

    See file, 'COPYING', for details.
*/

#include <cstdint>

#ifndef _WIN32
#include <unistd.h>
#endif

#include <common/cmdlib.hh>
#include <common/bspfile.hh>
#include <common/bsputils.hh>
#include <common/mathlib.hh>
#include <common/fs.hh>

#include "decompile.h"

#include <map>
#include <set>
#include <list>
#include <algorithm> // std::sort
#include <string>
#include <fstream>
#include <light/light.hh>

/* FIXME - share header with qbsp, etc. */
struct wadinfo_t
{
    std::array<char, 4> identification = {'W', 'A', 'D', '2'}; // should be WAD2
    int32_t numlumps;
    int32_t infotableofs = sizeof(wadinfo_t);

    auto stream_data() { return std::tie(identification, numlumps, infotableofs); }
};

struct lumpinfo_t
{
    int32_t filepos;
    int32_t disksize;
    int32_t size; // uncompressed
    char type;
    char compression;
    char pad1, pad2;
    std::array<char, 16> name; // must be null terminated

    auto stream_data() { return std::tie(filepos, disksize, size, type, compression, pad1, pad2, name); }
};

static void ExportWad(std::ofstream &wadfile, mbsp_t *bsp)
{
    int filepos, numvalid;
    const auto &texdata = bsp->dtex;

    /* Count up the valid lumps */
    numvalid = 0;
    for (auto &texture : texdata.textures)
        if (texture.data[0])
            numvalid++;

    // Write out
    wadinfo_t header;
    header.numlumps = numvalid;
    wadfile <= header;

    lumpinfo_t lump{};
    lump.type = 'D';

    /* Miptex data will follow the lump headers */
    filepos = sizeof(header) + numvalid * sizeof(lump);
    for (auto &miptex : texdata.textures) {
        if (!miptex.data[0])
            continue;

        lump.filepos = filepos;
        lump.size = sizeof(dmiptex_t) + miptex.width * miptex.height / 64 * 85;
        lump.disksize = lump.size;
        snprintf(lump.name.data(), sizeof(lump.name), "%s", miptex.name.data());

        filepos += lump.disksize;

        // Write it out
        wadfile <= lump;
    }
    for (auto &miptex : texdata.textures) {
        if (!miptex.data[0])
            continue;

        miptex.stream_write(wadfile);
    }
}

static void PrintModelInfo(const mbsp_t *bsp)
{
    for (size_t i = 0; i < bsp->dmodels.size(); i++) {
        const dmodelh2_t *dmodel = &bsp->dmodels[i];
        LogPrint("model {:3}: {:5} faces (firstface = {})\n", i, dmodel->numfaces, dmodel->firstface);
    }
}

/*
 * Quick hack to check verticies of faces lie on the correct plane
 */
constexpr vec_t PLANE_ON_EPSILON = 0.01;

static void CheckBSPFacesPlanar(const mbsp_t *bsp)
{
    for (size_t i = 0; i < bsp->dfaces.size(); i++) {
        const mface_t *face = BSP_GetFace(bsp, i);
        dplane_t plane = bsp->dplanes[face->planenum];

        if (face->side) {
            plane = -plane;
        }

        for (size_t j = 0; j < face->numedges; j++) {
            const int edgenum = bsp->dsurfedges[face->firstedge + j];
            const int vertnum = (edgenum >= 0) ? bsp->dedges[edgenum][0] : bsp->dedges[-edgenum][1];
            const qvec3f &point = bsp->dvertexes[vertnum];
            const float dist = plane.distance_to(point);

            if (dist < -PLANE_ON_EPSILON || dist > PLANE_ON_EPSILON)
                fmt::print("WARNING: face {}, point {} off plane by {}\n", i, j, dist);
        }
    }
}

static int Node_Height(const mbsp_t *bsp, const bsp2_dnode_t *node, std::map<const bsp2_dnode_t *, int> *cache)
{
    // leafs have a height of 0
    int child_heights[2] = {0, 0};

    for (int i = 0; i < 2; i++) {
        const int child = node->children[i];
        if (child >= 0) {
            child_heights[i] = Node_Height(bsp, &bsp->dnodes[child], cache);
        }
    }

    const int height = max(child_heights[0], child_heights[1]) + 1;
    if (cache)
        (*cache)[node] = height;
    return height;
}

static void PrintNodeHeights(const mbsp_t *bsp)
{
    // get all the heights in one go.
    const bsp2_dnode_t *headnode = &bsp->dnodes[bsp->dmodels[0].headnode[0]];
    std::map<const bsp2_dnode_t *, int> cache;
    Node_Height(bsp, headnode, &cache);

    const int maxlevel = 3;

    using level_t = int;
    using visit_t = std::pair<const bsp2_dnode_t *, level_t>;

    int current_level = -1;

    std::list<visit_t> tovisit{std::make_pair(headnode, 0)};
    while (!tovisit.empty()) {
        const auto n = tovisit.front();
        tovisit.pop_front();

        const bsp2_dnode_t *node = n.first;
        const int level = n.second;

        Q_assert(level <= maxlevel);

        // handle this node
        if (level != current_level) {
            current_level = level;
            fmt::print("\nNode heights at level {}: ", level);
        }

        // print the level of this node
        fmt::print("{}, ", cache.at(node));

        // add child nodes to the bfs
        if (level < maxlevel) {
            for (int i = 0; i < 2; i++) {
                const int child = node->children[i];
                if (child >= 0) {
                    tovisit.emplace_back(&bsp->dnodes[child], level + 1);
                }
            }
        }
    }
    printf("\n");
}

static void CheckBSPFile(const mbsp_t *bsp)
{
    int i;

    // FIXME: Should do a better reachability check where we traverse the
    // nodes/leafs to find reachable faces.
    std::set<int32_t> referenced_texinfos;
    std::set<int32_t> referenced_planenums;
    std::set<uint32_t> referenced_vertexes;
    std::set<uint8_t> used_lightstyles;

    /* faces */
    for (i = 0; i < bsp->dfaces.size(); i++) {
        const mface_t *face = BSP_GetFace(bsp, i);

        /* texinfo bounds check */
        if (face->texinfo < 0)
            fmt::print("warning: face {} has negative texinfo ({})\n", i, face->texinfo);
        if (face->texinfo >= bsp->texinfo.size())
            fmt::print("warning: face {} has texinfo out of range ({} >= {})\n", i, face->texinfo, bsp->texinfo.size());
        referenced_texinfos.insert(face->texinfo);

        /* planenum bounds check */
        if (face->planenum < 0)
            fmt::print("warning: face {} has negative planenum ({})\n", i, face->planenum);
        if (face->planenum >= bsp->dplanes.size())
            fmt::print(
                "warning: face {} has planenum out of range ({} >= {})\n", i, face->planenum, bsp->dplanes.size());
        referenced_planenums.insert(face->planenum);

        /* lightofs check */
        if (face->lightofs < -1)
            fmt::print("warning: face {} has negative light offset ({})\n", i, face->lightofs);
        if (face->lightofs >= bsp->dlightdata.size())
            fmt::print("warning: face {} has light offset out of range "
                       "({} >= {})\n",
                i, face->lightofs, bsp->dlightdata.size());

        /* edge check */
        if (face->firstedge < 0)
            fmt::print("warning: face {} has negative firstedge ({})\n", i, face->firstedge);
        if (face->numedges < 3)
            fmt::print("warning: face {} has < 3 edges ({})\n", i, face->numedges);
        if (face->firstedge + face->numedges > bsp->dsurfedges.size())
            fmt::print("warning: face {} has edges out of range ({}..{} >= {})\n", i, face->firstedge,
                face->firstedge + face->numedges - 1, bsp->dsurfedges.size());

        for (int j = 0; j < 4; j++) {
            used_lightstyles.insert(face->styles[j]);
        }
    }

    /* edges */
    for (i = 0; i < bsp->dedges.size(); i++) {
        const bsp2_dedge_t *edge = &bsp->dedges[i];
        int j;

        for (j = 0; j < 2; j++) {
            const uint32_t vertex = (*edge)[j];
            if (vertex > bsp->dvertexes.size())
                fmt::print("warning: edge {} has vertex {} out range "
                           "({} >= {})\n",
                    i, j, vertex, bsp->dvertexes.size());
            referenced_vertexes.insert(vertex);
        }
    }

    /* surfedges */
    for (i = 0; i < bsp->dsurfedges.size(); i++) {
        const int edgenum = bsp->dsurfedges[i];
        if (!edgenum)
            fmt::print("warning: surfedge {} has zero value!\n", i);
        if (abs(edgenum) >= bsp->dedges.size())
            fmt::print("warning: surfedge {} is out of range (abs({}) >= {})\n", i, edgenum, bsp->dedges.size());
    }

    /* marksurfaces */
    for (i = 0; i < bsp->dleaffaces.size(); i++) {
        const uint32_t surfnum = bsp->dleaffaces[i];
        if (surfnum >= bsp->dfaces.size())
            fmt::print("warning: marksurface {} is out of range ({} >= {})\n", i, surfnum, bsp->dfaces.size());
    }

    /* leafs */
    for (i = 0; i < bsp->dleafs.size(); i++) {
        const mleaf_t *leaf = &bsp->dleafs[i];
        const uint32_t endmarksurface = leaf->firstmarksurface + leaf->nummarksurfaces;
        if (endmarksurface > bsp->dleaffaces.size())
            fmt::print("warning: leaf {} has marksurfaces out of range "
                       "({}..{} >= {})\n",
                i, leaf->firstmarksurface, endmarksurface - 1, bsp->dleaffaces.size());
        if (leaf->visofs < -1)
            fmt::print("warning: leaf {} has negative visdata offset ({})\n", i, leaf->visofs);
        if (leaf->visofs >= bsp->dvis.bits.size())
            fmt::print("warning: leaf {} has visdata offset out of range "
                       "({} >= {})\n",
                i, leaf->visofs, bsp->dvis.bits.size());
    }

    /* nodes */
    for (i = 0; i < bsp->dnodes.size(); i++) {
        const bsp2_dnode_t *node = &bsp->dnodes[i];
        int j;

        for (j = 0; j < 2; j++) {
            const int32_t child = node->children[j];
            if (child >= 0 && child >= bsp->dnodes.size())
                fmt::print("warning: node {} has child {} (node) out of range "
                           "({} >= {})\n",
                    i, j, child, bsp->dnodes.size());
            if (child < 0 && -child - 1 >= bsp->dleafs.size())
                fmt::print("warning: node {} has child {} (leaf) out of range "
                           "({} >= {})\n",
                    i, j, -child - 1, bsp->dleafs.size());
        }

        if (node->children[0] == node->children[1]) {
            fmt::print("warning: node {} has both children {}\n", i, node->children[0]);
        }

        referenced_planenums.insert(node->planenum);
    }

    /* clipnodes */
    for (i = 0; i < bsp->dclipnodes.size(); i++) {
        const bsp2_dclipnode_t *clipnode = &bsp->dclipnodes[i];

        for (int j = 0; j < 2; j++) {
            const int32_t child = clipnode->children[j];
            if (child >= 0 && child >= bsp->dclipnodes.size())
                fmt::print("warning: clipnode {} has child {} (clipnode) out of range "
                           "({} >= {})\n",
                    i, j, child, bsp->dclipnodes.size());
            if (child < 0 && child < CONTENTS_MIN)
                fmt::print("warning: clipnode {} has invalid contents ({}) for child {}\n", i, child, j);
        }

        if (clipnode->children[0] == clipnode->children[1]) {
            fmt::print("warning: clipnode {} has both children {}\n", i, clipnode->children[0]);
        }

        referenced_planenums.insert(clipnode->planenum);
    }

    /* TODO: finish range checks, add "unreferenced" checks... */

    /* unreferenced texinfo */
    {
        int num_unreferenced_texinfo = 0;
        for (i = 0; i < bsp->texinfo.size(); i++) {
            if (referenced_texinfos.find(i) == referenced_texinfos.end()) {
                num_unreferenced_texinfo++;
            }
        }
        if (num_unreferenced_texinfo)
            fmt::print("warning: {} texinfos are unreferenced\n", num_unreferenced_texinfo);
    }

    /* unreferenced planes */
    {
        int num_unreferenced_planes = 0;
        for (i = 0; i < bsp->dplanes.size(); i++) {
            if (referenced_planenums.find(i) == referenced_planenums.end()) {
                num_unreferenced_planes++;
            }
        }
        if (num_unreferenced_planes)
            fmt::print("warning: {} planes are unreferenced\n", num_unreferenced_planes);
    }

    /* unreferenced vertices */
    {
        int num_unreferenced_vertexes = 0;
        for (i = 0; i < bsp->dvertexes.size(); i++) {
            if (referenced_vertexes.find(i) == referenced_vertexes.end()) {
                num_unreferenced_vertexes++;
            }
        }
        if (num_unreferenced_vertexes)
            fmt::print("warning: {} vertexes are unreferenced\n", num_unreferenced_vertexes);
    }

    /* tree balance */
    PrintNodeHeights(bsp);

    /* unique visofs's */
    std::set<int32_t> visofs_set;
    for (i = 0; i < bsp->dleafs.size(); i++) {
        const mleaf_t *leaf = &bsp->dleafs[i];
        if (leaf->visofs >= 0) {
            visofs_set.insert(leaf->visofs);
        }
    }
    fmt::print("{} unique visdata offsets for {} leafs\n", visofs_set.size(), bsp->dleafs.size());
    fmt::print("{} visleafs in world model\n", bsp->dmodels[0].visleafs);

    /* unique lightstyles */
    fmt::print("{} lightstyles used:\n", used_lightstyles.size());
    {
        std::vector<uint8_t> v(used_lightstyles.begin(), used_lightstyles.end());
        std::sort(v.begin(), v.end());
        for (uint8_t style : v) {
            fmt::print("\t{}\n", style);
        }
    }

    fmt::print("world mins: {} maxs: {}\n", bsp->dmodels[0].mins, bsp->dmodels[0].maxs);
}

static void CompareBSPFiles(const mbsp_t &refBsp, const mbsp_t &bsp)
{
    fmt::print("comparing {} with {} faces\n", refBsp.dfaces.size(), bsp.dfaces.size());

    const dmodelh2_t *world = BSP_GetWorldModel(&bsp);
    const dmodelh2_t *refWorld = BSP_GetWorldModel(&refBsp);

    // iterate through the refBsp world faces
    for (int i = 0; i < refWorld->numfaces; i++) {
        auto *refFace = BSP_GetFace(&refBsp, refWorld->firstface + i);
        qvec3f refFaceCentroid = Face_Centroid(&refBsp, refFace);
        qvec3d wantedNormal = Face_Normal(&refBsp, refFace);

        // Search for a face in bsp touching refFaceCentroid.
        auto *matchedFace = BSP_FindFaceAtPoint(&bsp, world, refFaceCentroid, wantedNormal);
        if (matchedFace == nullptr) {
            fmt::print("couldn't find a face at {} normal {}\n", refFaceCentroid, wantedNormal);
        }

        // TODO: run on some more complex maps
        //        auto* refFaceSelfCheck = BSP_FindFaceAtPoint(refBsp, refWorld, wantedPoint, wantedNormal);
        //        if (refFaceSelfCheck == refFace) {
        //            matches ++;
        //        } else {
        //            fmt::print("not match at {} {} {} wanted {} got {}\n", wantedPoint[0], wantedPoint[1],
        //            wantedPoint[2], refFace, refFaceSelfCheck); Face_DebugPrint(refBsp, refFace);
        //            Face_DebugPrint(refBsp, refFaceSelfCheck); notmat++;
        //        }
    }
}

static void FindFaces(const mbsp_t *bsp, const qvec3d &pos, const qvec3d &normal)
{
    for (int i = 0; i < bsp->dmodels.size(); ++i) {
        const dmodelh2_t *model = &bsp->dmodels[i];
        const mface_t *face = BSP_FindFaceAtPoint(bsp, model, pos, normal);

        if (face != nullptr) {
            fmt::print("model {} face {}: texture '{}' texinfo {}\n", i, Face_GetNum(bsp, face),
                Face_TextureName(bsp, face), face->texinfo);
        }
    }
}

int main(int argc, char **argv)
{
    bspdata_t bspdata;
    mbsp_t &bsp = bspdata.bsp.emplace<mbsp_t>();

    printf("---- bsputil / ericw-tools " stringify(ERICWTOOLS_VERSION) " ----\n");
    if (argc == 1) {
        printf(
            "usage: bsputil [--extract-entities] [--extract-textures] [--convert bsp29|bsp2|bsp2rmq|q2bsp] [--check] [--modelinfo]\n"
            "[--check] [--compare otherbsp] [--findfaces x y z nx ny nz] [--settexinfo facenum texinfonum]\n"
            "[--decompile] [--decompile-geomonly] bspfile\n");
        exit(1);
    }

    std::filesystem::path source = DefaultExtension(argv[argc - 1], "bsp");
    printf("---------------------\n");
    fmt::print("{}\n", source);

    LoadBSPFile(source, &bspdata);

    bspdata.version->game->init_filesystem(source);

    ConvertBSPFormat(&bspdata, &bspver_generic);

    for (int32_t i = 0; i < argc - 1; i++) {
        if (!strcmp(argv[i], "--compare")) {
            i++;
            if (i == argc - 1) {
                Error("--compare requires two arguments");
            }
            // Load the reference BSP

            std::filesystem::path refbspname = DefaultExtension(argv[i], "bsp");

            bspdata_t refbspdata;
            LoadBSPFile(refbspname, &refbspdata);
            ConvertBSPFormat(&refbspdata, &bspver_generic);

            fmt::print("comparing reference bsp {} with test bsp {}\n", refbspname, source);

            CompareBSPFiles(std::get<mbsp_t>(refbspdata.bsp), bsp);

            break;
        } else if (!strcmp(argv[i], "--convert")) {
            i++;
            if (!(i < argc - 1)) {
                Error("--convert requires an argument");
            }

            const bspversion_t *fmt = nullptr;

            for (const bspversion_t *bspver : bspversions) {
                if (!strcmp(argv[i], bspver->short_name)) {
                    fmt = bspver;
                    break;
                }
            }

            if (!fmt) {
                Error("Unsupported format {}", argv[i]);
            }

            ConvertBSPFormat(&bspdata, fmt);

            WriteBSPFile(source.replace_filename(source.stem().string() + "-" + argv[i]), &bspdata);

        } else if (!strcmp(argv[i], "--extract-entities")) {
            uint32_t crc = CRC_Block((unsigned char *)bsp.dentdata.data(), bsp.dentdata.size() - 1);

            source.replace_extension(".ent");
            fmt::print("-> writing {} [CRC: {:04x}]... ", source, crc);

            std::ofstream f(source, std::ios_base::out | std::ios_base::binary);
            if (!f)
                Error("couldn't open {} for writing\n", source);

            f << bsp.dentdata;

            if (!f)
                Error("{}", strerror(errno));

            f.close();

            printf("done.\n");
        } else if (!strcmp(argv[i], "--extract-textures")) {
            source.replace_extension(".wad");
            fmt::print("-> writing {}... ", source);

            std::ofstream f(source);

            if (!f)
                Error("couldn't open {} for writing\n", source);

            ExportWad(f, &bsp);

            printf("done.\n");
        } else if (!strcmp(argv[i], "--check")) {
            printf("Beginning BSP data check...\n");
            CheckBSPFile(&bsp);
            CheckBSPFacesPlanar(&bsp);
            printf("Done.\n");
        } else if (!strcmp(argv[i], "--modelinfo")) {
            PrintModelInfo(&bsp);
        } else if (!strcmp(argv[i], "--findfaces")) {
            // (i + 1) ... (i + 6) = x y z nx ny nz
            // i + 7 = bsp file

            if (i + 7 >= argc) {
                Error("--findfaces requires 6 arguments");
            }

            try {
                const qvec3d pos {std::stof(argv[i + 1]), std::stof(argv[i + 2]), std::stof(argv[i + 3])};
                const qvec3d normal {std::stof(argv[i + 4]), std::stof(argv[i + 5]), std::stof(argv[i + 6])};
                FindFaces(&bsp, pos, normal);
            }
            catch (const std::exception &) {
                Error("Error reading position/normal\n");
            }
            return 0;
        } else if (!strcmp(argv[i], "--settexinfo")) {
            // (i + 1) facenum
            // (i + 2) texinfonum

            if (i + 2 >= argc) {
                Error("--settexinfo requires 2 arguments");
            }

            const int fnum = std::stoi(argv[i + 1]);
            const int texinfonum = std::stoi(argv[i + 2]);

            mface_t *face = BSP_GetFace(&bsp, fnum);
            face->texinfo = texinfonum;

            ConvertBSPFormat(&bspdata, bspdata.loadversion);

            // Overwrite source bsp!
            WriteBSPFile(source, &bspdata);

            return 0;
        } else if (!strcmp(argv[i], "--decompile") || !strcmp(argv[i], "--decompile-geomonly")) {
            const bool geomOnly = !strcmp(argv[i], "--decompile-geomonly");

            source.replace_extension("");
            source.replace_filename(source.stem().string() + "-decompile");
            source.replace_extension(".map");
            fmt::print("-> writing {}...\n", source);

            std::ofstream f(source);

            if (!f)
                Error("couldn't open {} for writing\n", source);

            decomp_options options;
            options.geometryOnly = geomOnly;

            DecompileBSP(&bsp, options, f);

            f.close();

            if (!f)
                Error("{}", strerror(errno));

            printf("done!\n");
            return 0;
        }
    }

    printf("---------------------\n");

    return 0;
}