#include "rendering/m2_model_classifier.hpp"

#include <algorithm>
#include <array>
#include <cctype>
#include <string_view>

namespace wowee {
namespace rendering {

namespace {

// Returns true if `lower` contains `token` as a substring.
// Caller must provide an already-lowercased string.
inline bool has(const std::string& lower, std::string_view token) noexcept {
    return lower.find(token) != std::string::npos;
}

// Returns true if any token in the compile-time array is a substring of `lower`.
template <std::size_t N>
bool hasAny(const std::string& lower,
            const std::array<std::string_view, N>& tokens) noexcept {
    for (auto tok : tokens)
        if (lower.find(tok) != std::string::npos) return true;
    return false;
}

} // namespace

M2ClassificationResult classifyM2Model(
    const std::string& name,
    const glm::vec3&   boundsMin,
    const glm::vec3&   boundsMax,
    std::size_t        vertexCount,
    std::size_t        emitterCount)
{
    // Single lowercased copy — all token checks share it.
    std::string n = name;
    std::transform(n.begin(), n.end(), n.begin(),
                   [](unsigned char c) { return static_cast<char>(std::tolower(c)); });

    M2ClassificationResult r;

    // ---------------------------------------------------------------
    // Geometry metrics
    // ---------------------------------------------------------------
    const glm::vec3 dims = boundsMax - boundsMin;
    const float horiz    = std::max(dims.x, dims.y);
    const float vert     = std::max(0.0f, dims.z);
    const bool lowWide   = (horiz > 1.4f && vert > 0.2f && vert < horiz * 0.70f);
    const bool lowPlat   = (horiz > 1.8f && vert > 0.2f && vert < 1.8f);

    // ---------------------------------------------------------------
    // Simple single-token flags
    // ---------------------------------------------------------------
    r.isInvisibleTrap = has(n, "invisibletrap");
    r.isGroundDetail  = has(n, "\\nodxt\\detail\\") || has(n, "\\detail\\");
    r.isSmoke         = has(n, "smoke");
    r.isLavaModel     = has(n, "forgelava") || has(n, "lavapot") || has(n, "lavaflow");

    r.isInstancePortal  = has(n, "instanceportal") || has(n, "instancenewportal")
                        || has(n, "portalfx")       || has(n, "spellportal");

    r.isWaterVegetation = has(n, "cattail") || has(n, "reed")     || has(n, "bulrush")
                        || has(n, "seaweed") || has(n, "kelp")    || has(n, "lilypad");

    r.isElvenLike   = has(n, "elf")     || has(n, "elven") || has(n, "quel");
    r.isLanternLike = has(n, "lantern") || has(n, "lamp")  || has(n, "light");
    r.isKoboldFlame = has(n, "kobold")
                    && (has(n, "candle") || has(n, "torch") || has(n, "mine"));

    // ---------------------------------------------------------------
    // Collision: shape categories (mirrors original logic ordering)
    // ---------------------------------------------------------------
    const bool isPlanter      = has(n, "planter");
    const bool likelyCurb     = isPlanter || has(n, "curb")  || has(n, "base")
                                           || has(n, "ring")  || has(n, "well");
    const bool knownSwPlanter = has(n, "stormwindplanter")
                              || has(n, "stormwindwindowplanter");
    const bool bridgeName     = has(n, "bridge") || has(n, "plank") || has(n, "walkway");
    const bool statueName     = has(n, "statue") || has(n, "monument") || has(n, "sculpture");
    const bool sittable       = has(n, "chair")  || has(n, "bench") || has(n, "stool")
                                                 || has(n, "seat")  || has(n, "throne");
    const bool smallSolid     = (statueName && !sittable)
                              || has(n, "crate") || has(n, "box")
                              || has(n, "chest") || has(n, "barrel");
    const bool chestName      = has(n, "chest");

    r.collisionSteppedFountain    = has(n, "fountain");
    r.collisionSteppedLowPlatform = !r.collisionSteppedFountain
                                  && (knownSwPlanter || bridgeName
                                      || (likelyCurb && (lowPlat || lowWide)));
    r.collisionBridge             = bridgeName;
    r.collisionPlanter            = isPlanter;
    r.collisionStatue             = statueName;

    const bool narrowVertName  = has(n, "lamp")    || has(n, "lantern")
                               || has(n, "post")    || has(n, "pole");
    const bool narrowVertShape = (horiz > 0.12f && horiz < 2.0f
                               && vert  > 2.2f  && vert  > horiz * 1.8f);
    r.collisionNarrowVerticalProp = !r.collisionSteppedFountain
                                  && !r.collisionSteppedLowPlatform
                                  && (narrowVertName || narrowVertShape);

    // ---------------------------------------------------------------
    // Foliage token table (sorted alphabetically)
    // ---------------------------------------------------------------
    static constexpr auto kFoliageTokens = std::to_array<std::string_view>({
        "algae",      "bamboo",     "banana",     "branch",     "bush",
        "cactus",     "canopy",     "cattail",    "coconut",    "coral",
        "corn",       "crop",       "dead-grass", "dead_grass", "deadgrass",
        "dry-grass",  "dry_grass",  "drygrass",
        "fern",       "fireflies",  "firefly",    "fireflys",
        "flower",     "frond",      "fungus",     "gourd",      "grass",
        "hay",        "hedge",      "ivy",        "kelp",       "leaf",
        "leaves",     "lily",       "melon",      "moss",       "mushroom",
        "palm",       "pumpkin",    "reed",       "root",       "seaweed",
        "shrub",      "squash",     "stalk",      "thorn",      "toadstool",
        "vine",       "watermelon", "weed",       "wheat",
    });

    // "plant" is foliage unless "planter" is also present (planters are solid curbs).
    const bool foliagePlant = has(n, "plant") && !isPlanter;
    const bool foliageName  = foliagePlant || hasAny(n, kFoliageTokens);
    const bool treeLike     = has(n, "tree");
    const bool hardTreePart = has(n, "trunk") || has(n, "stump") || has(n, "log");

    // Trees wide/tall enough to have a visible trunk → solid cylinder collision.
    const bool treeWithTrunk = treeLike && !hardTreePart && !foliageName
                             && horiz > 6.0f && vert > 4.0f;
    const bool softTree      = treeLike && !hardTreePart && !treeWithTrunk;

    r.collisionTreeTrunk = treeWithTrunk;

    const bool genericSolid     = (horiz > 0.6f && horiz < 6.0f
                                && vert  > 0.30f && vert  < 4.0f
                                && vert  > horiz * 0.16f) || statueName;
    const bool curbLikeName     = has(n, "curb")   || has(n, "planter")
                                || has(n, "ring")   || has(n, "well")  || has(n, "base");
    const bool lowPlatLikeShape = lowWide || lowPlat;

    r.collisionSmallSolidProp = !r.collisionSteppedFountain
                              && !r.collisionSteppedLowPlatform
                              && !r.collisionNarrowVerticalProp
                              && !r.collisionTreeTrunk
                              && !curbLikeName
                              && !lowPlatLikeShape
                              && (smallSolid
                                  || (genericSolid && !foliageName && !softTree));

    const bool carpetOrRug    = has(n, "carpet") || has(n, "rug");
    const bool forceSolidCurb = r.collisionSteppedLowPlatform || knownSwPlanter
                              || likelyCurb || r.collisionPlanter;
    r.collisionNoBlock        = (foliageName || softTree || carpetOrRug) && !forceSolidCurb;
    // Ground-clutter detail cards are always non-blocking.
    if (r.isGroundDetail) r.collisionNoBlock = true;

    // ---------------------------------------------------------------
    // Ambient creatures: fireflies, dragonflies, moths, butterflies
    // ---------------------------------------------------------------
    static constexpr auto kAmbientTokens = std::to_array<std::string_view>({
        "butterfly", "dragonflies", "dragonfly",
        "fireflies", "firefly",     "fireflys", "moth",
    });
    const bool ambientCreature = hasAny(n, kAmbientTokens);

    // ---------------------------------------------------------------
    // Animation / foliage rendering flags
    // ---------------------------------------------------------------
    const bool foliageOrTree = foliageName || treeLike;
    r.isFoliageLike    = foliageOrTree && !ambientCreature;
    r.disableAnimation = r.isFoliageLike || chestName;
    r.shadowWindFoliage = r.isFoliageLike;
    r.isFireflyEffect   = ambientCreature;

    // ---------------------------------------------------------------
    // Spell effects (named tokens + particle-dominated geometry heuristic)
    // ---------------------------------------------------------------
    static constexpr auto kEffectTokens = std::to_array<std::string_view>({
        "bubbles",        "hazardlight",      "instancenewportal", "instanceportal",
        "lavabubble",     "lavasplash",        "lavasteam",         "levelup",
        "lightshaft",     "mageportal",        "particleemitter",
        "spotlight",      "volumetriclight",   "wisps",             "worldtreeportal",
    });
    r.isSpellEffect = hasAny(n, kEffectTokens)
                    || (emitterCount >= 3 && vertexCount <= 200);
    // Instance portals are spell effects too.
    if (r.isInstancePortal) r.isSpellEffect = true;

    return r;
}

// ---------------------------------------------------------------------------
// classifyBatchTexture
// ---------------------------------------------------------------------------

M2BatchTexClassification classifyBatchTexture(const std::string& lowerTexKey)
{
    M2BatchTexClassification r;

    // Exact paths for well-known lantern / lamp glow-card textures.
    static constexpr auto kExactGlowTextures = std::to_array<std::string_view>({
        "world\\azeroth\\karazahn\\passivedoodads\\bonfire\\flamelicksmallblue.blp",
        "world\\expansion06\\doodads\\nightelf\\7ne_druid_streetlamp01_light.blp",
        "world\\generic\\human\\passive doodads\\stormwind\\t_vfx_glow01_64.blp",
        "world\\generic\\nightelf\\passive doodads\\lamps\\glowblue32.blp",
        "world\\generic\\nightelf\\passive doodads\\magicalimplements\\glow.blp",
    });
    for (auto s : kExactGlowTextures)
        if (lowerTexKey == s) { r.exactLanternGlowTex = true; break; }

    static constexpr auto kGlowTokens = std::to_array<std::string_view>({
        "flare", "glow", "halo", "light",
    });
    static constexpr auto kFlameTokens = std::to_array<std::string_view>({
        "ember", "fire", "flame", "flamelick",
    });
    static constexpr auto kGlowCardTokens = std::to_array<std::string_view>({
        "flamelick", "genericglow", "glow", "glowball",
        "lensflare", "lightbeam",   "t_vfx",
    });
    static constexpr auto kLikelyFlameTokens = std::to_array<std::string_view>({
        "fire", "flame", "torch",
    });
    static constexpr auto kLanternFamilyTokens = std::to_array<std::string_view>({
        "elf", "lamp", "lantern", "quel", "silvermoon", "thalas",
    });
    static constexpr auto kCoolTintTokens = std::to_array<std::string_view>({
        "arcane", "blue", "nightelf",
    });
    static constexpr auto kRedTintTokens = std::to_array<std::string_view>({
        "red", "ruby", "scarlet",
    });

    r.hasGlowToken     = hasAny(lowerTexKey, kGlowTokens);
    r.hasFlameToken    = hasAny(lowerTexKey, kFlameTokens);
    r.hasGlowCardToken = hasAny(lowerTexKey, kGlowCardTokens);
    r.likelyFlame      = hasAny(lowerTexKey, kLikelyFlameTokens);
    r.lanternFamily    = hasAny(lowerTexKey, kLanternFamilyTokens);
    r.glowTint         = hasAny(lowerTexKey, kCoolTintTokens) ? 1
                       : hasAny(lowerTexKey, kRedTintTokens)  ? 2
                       : 0;

    return r;
}

} // namespace rendering
} // namespace wowee