#include <limits>
#include "luastack.hpp"
#include "animqueue.hpp"

AnimStep::AnimStep() {
    clear();
}

AnimStep::~AnimStep() {}

void AnimStep::clear() {
    id_ = 0;
    bits_ = 0;
    action_ = "";
    facing_ = 0;
    xyz_ = util::XYZ(0,0,0);
    graphic_ = "";
    plane_ = "";
}

void AnimStep::set_action(const std::string &act) {
    action_ = act;
}

void AnimStep::set_facing(float f) {
    bits_ |= HAS_FACING;
    facing_ = f;
}

void AnimStep::set_x(float f) {
    bits_ |= HAS_X;
    xyz_.x = f;
}

void AnimStep::set_y(float f) {
    bits_ |= HAS_Y;
    xyz_.y = f;
}

void AnimStep::set_z(float f) {
    bits_ |= HAS_Z;
    xyz_.z = f;
}

void AnimStep::set_xyz(const util::XYZ &xyz) {
    bits_ |= (HAS_X | HAS_Y | HAS_Z);
    xyz_ = xyz;
}

void AnimStep::set_graphic(const std::string &g) {
    bits_ |= HAS_GRAPHIC;
    graphic_ = g;
}

void AnimStep::set_plane(const std::string &p) {
    bits_ |= HAS_PLANE;
    plane_ = p;
}

AnimQueue::AnimQueue() {
    size_limit_ = 10; // Default size limit.
    clear_steps();
}

void AnimStep::from_lua_store_string(lua_State *L, int idx, std::string *target, int16_t bits, const char *name) {
    if ((bits_ & bits)||(*target != "")) {
        luaL_error(L, "specified %s twice", name);
    }
    if (lua_type(L, idx) != LUA_TSTRING) {
        luaL_error(L, "Expected %s to be a string", name);
    }
    *target = lua_tostring(L, idx);
    bits_ |= bits;
}

void AnimStep::from_lua_store_number(lua_State *L, int idx, float *target, float offset, int16_t bits, const char *name) {
    if (bits_ & bits) {
        luaL_error(L, "specified %s twice", name);
    }
    if (lua_type(L, idx) != LUA_TNUMBER) {
        luaL_error(L, "Expected %s to be a number", name);
    }
    *target = lua_tonumber(L, idx) + offset;
    bits_ |= bits;
}

void AnimStep::from_lua(lua_State *L, int idx, const AnimStep &qback) {
    LuaSpecial tab(idx);
    LuaVar key, value;
    LuaStack LS(L, key, value);
    if (!LS.istable(tab)) {
        luaL_error(L, "animation spec must be a table");
    }
    LS.set(key, LuaNil);
    while (LS.next(tab, key, value)) {
        if (!LS.isstring(key)) {
            luaL_error(L, "animation specs must be key/value where key is a string");
        }
        std::string skey = LS.ckstring(key);
        if (skey == "action") {
            from_lua_store_string(L, value.index(), &action_, 0, "action");
        } else if (skey == "graphic") {
            from_lua_store_string(L, value.index(), &graphic_, HAS_GRAPHIC, "graphic");
        } else if (skey == "plane") {
            from_lua_store_string(L, value.index(), &plane_, HAS_PLANE, "plane");
        } else if (skey == "x") {
            from_lua_store_number(L, value.index(), &xyz_.x, 0.0, HAS_X, "X coordinate");
        } else if (skey == "y") {
            from_lua_store_number(L, value.index(), &xyz_.y, 0.0, HAS_Y, "Z coordinate");
        } else if (skey == "z") {
            from_lua_store_number(L, value.index(), &xyz_.z, 0.0, HAS_Z, "Z coordinate");
        } else if (skey == "dx") {
            from_lua_store_number(L, value.index(), &xyz_.x, qback.xyz().x, HAS_X, "X coordinate");
        } else if (skey == "dy") {
            from_lua_store_number(L, value.index(), &xyz_.y, qback.xyz().y, HAS_Y, "Y coordinate");
        } else if (skey == "dz") {
            from_lua_store_number(L, value.index(), &xyz_.z, qback.xyz().z, HAS_Z, "Z coordinate");
        } else if (skey == "facing") {
            from_lua_store_number(L, value.index(), &facing_, 0.0, HAS_FACING, "facing");
        } else {
            luaL_error(L, "Unrecognized animation spec: %s", skey.c_str());
        }
    }
}

void AnimStep::echo(const AnimStep &prev) {
    if (!has_facing()) {
        facing_ = prev.facing_;
    }
    if (!has_x()) {
        xyz_.x = prev.xyz_.x;
    }
    if (!has_y()) {
        xyz_.y = prev.xyz_.y;
    }
    if (!has_z()) {
        xyz_.z = prev.xyz_.z;
    }
    if (!has_graphic()) {
        graphic_ = prev.graphic_;
    }
    if (!has_plane()) {
        plane_ = prev.plane_;
    }
}

bool AnimStep::echoes(const AnimStep &prev) const {
    if (!has_facing() && (facing_ != prev.facing_)) {
        return false;
    }
    if (!has_x() && (xyz_.x != prev.xyz_.x)) {
        return false;
    }
    if (!has_y() && (xyz_.y != prev.xyz_.y)) {
        return false;
    }
    if (!has_z() && (xyz_.z != prev.xyz_.z)) {
        return false;
    }
    if (!has_graphic() && (graphic_ != prev.graphic_)) {
        return false;
    }
    if (!has_plane() && (plane_ != prev.plane_)) {
        return false;
    }
    return true;
}

void AnimQueue::clear_steps() {
    steps_.clear();
    steps_.emplace_back();
    AnimStep &init = steps_.back();
    init.bits_ = AnimStep::HAS_EVERYTHING;
    init.action_ = "";
    init.graphic_ = "";
    init.plane_ = "";
}

void AnimQueue::set_size_limit(int n) {
    assert(n >= 2);
    size_limit_ = n;
}

void AnimQueue::keep_only(int n) {
    if (n < 1) n = 1;
    while (int(steps_.size()) > n) {
        steps_.pop_front();
    }
    AnimStep &init = steps_.front();
    init.id_ = 0;
    init.action_ = "";
    init.bits_ = AnimStep::HAS_EVERYTHING;
}

void AnimQueue::add(int64_t id, const AnimStep &step) {
    AnimStep copy = step;
    copy.echo(steps_.back());
    copy.id_ = id;
    steps_.push_back(copy);
    keep_only(size_limit_);
}

bool AnimQueue::valid() {
    // Animqueue must have at least one step.
    if (steps_.empty()) {
        return false;
    }
    // First action should be blank.
    if (steps_[0].action_ != "") {
        return false;
    }
    // First step should have all bits.
    if (steps_[0].bits_ != AnimStep::HAS_EVERYTHING) {
        return false;
    }
    // Any unset bit should correspond to a value copied from the previous step.
    for (size_t i = 1; i < steps_.size(); i++) {
        const AnimStep &prev = steps_[i - 1];
        const AnimStep &curr = steps_[i];
        if (!curr.echoes(prev)) return false;
    }
    return true;
}

void AnimQueue::serialize(StreamBuffer *sb) {
    assert(valid()); // can't serialize an invalid animqueue.
    sb->write_int32(size_limit_);
    sb->write_size(steps_.size());
    for (const AnimStep &step : steps_) {
        sb->write_int64(step.id_);
        sb->write_int16(step.bits_);
        sb->write_string(step.action_);
        if (step.has_facing()) {
            sb->write_float(step.facing_);
        }
        if (step.has_x()) {
            sb->write_float(step.xyz_.x);
        }
        if (step.has_y()) {
            sb->write_float(step.xyz_.y);
        }
        if (step.has_z()) {
            sb->write_float(step.xyz_.z);
        }
        if (step.has_graphic()) {
            sb->write_string(step.graphic_);
        }
        if (step.has_plane()) {
            sb->write_string(step.plane_);
        }
    }
}

void AnimQueue::deserialize(StreamBuffer *sb) {
    size_limit_ = sb->read_int32();
    size_t nsteps = sb->read_size();
    steps_.resize(nsteps);
    for (size_t i = 0; i < nsteps; i++) {
        AnimStep &step = steps_[i];
        if (i > 0) step = steps_[i - 1];
        step.id_ = sb->read_int64();
        step.bits_ = sb->read_int16();
        step.action_ = sb->read_string();
        if (step.has_facing()) {
            step.facing_ = sb->read_float();
        }
        if (step.has_x()) {
            step.xyz_.x = sb->read_float();
        }
        if (step.has_y()) {
            step.xyz_.y = sb->read_float();
        }
        if (step.has_z()) {
            step.xyz_.z = sb->read_float();
        }
        if (step.has_graphic()) {
            step.graphic_ = sb->read_string();
        }
        if (step.has_plane()) {
            step.plane_ = sb->read_string();
        }
    }
}

const AnimStep &AnimQueue::back() const {
    return steps_.back();
}

LuaDefine(unittests_animqueue, "c") {
    // Check initial state.
    AnimStep stp;
    AnimQueue aq;
    StreamBuffer sb;
    AnimQueue aqds;
    aq.set_size_limit(3);
    
    LuaAssert(L, aq.valid());
    LuaAssert(L, aq.size() == 1);
    const AnimStep *st = &aq.nth(0);
    LuaAssert(L, st->id() == 0);
    LuaAssert(L, st->action() == "");
    LuaAssert(L, st->bits() == AnimStep::HAS_EVERYTHING);
    LuaAssert(L, st->facing() == 0.0);
    LuaAssert(L, st->xyz() == util::XYZ(0,0,0));
    LuaAssert(L, st->graphic() == "");
    LuaAssert(L, st->plane() == "");

    // Test the step setters.
    stp.clear();
    stp.set_facing(180);
    LuaAssert(L, stp.facing() == 180);
    LuaAssert(L, stp.bits() == AnimStep::HAS_FACING);
    stp.set_x(3);
    LuaAssert(L, stp.xyz() == util::XYZ(3, 0, 0));
    LuaAssert(L, stp.bits() == (AnimStep::HAS_FACING | AnimStep::HAS_X));
    stp.set_y(4);
    LuaAssert(L, stp.xyz() == util::XYZ(3, 4, 0));
    LuaAssert(L, stp.bits() == (AnimStep::HAS_FACING | AnimStep::HAS_X | AnimStep::HAS_Y));
    stp.set_z(5);
    LuaAssert(L, stp.xyz() == util::XYZ(3, 4, 5));
    LuaAssert(L, stp.bits() == (AnimStep::HAS_FACING | AnimStep::HAS_X | AnimStep::HAS_Y | AnimStep::HAS_Z));
    stp.set_plane("somewhere");
    LuaAssert(L, stp.plane() == "somewhere");
    LuaAssert(L, stp.bits() == (AnimStep::HAS_FACING | AnimStep::HAS_XYZ | AnimStep::HAS_PLANE));
    stp.set_graphic("something");
    LuaAssert(L, stp.graphic() == "something");
    LuaAssert(L, stp.bits() == (AnimStep::HAS_FACING | AnimStep::HAS_XYZ | AnimStep::HAS_PLANE | AnimStep::HAS_GRAPHIC));

    // Add a step.
    stp.clear();
    stp.set_action("walk");
    aq.add(12345, stp);
    LuaAssert(L, aq.valid());
    LuaAssert(L, aq.size() == 2);
    st = &aq.nth(1);
    LuaAssert(L, st->id() == 12345);
    LuaAssert(L, st->action() == "walk");
    LuaAssert(L, st->bits() == 0);
    LuaAssert(L, st->facing() == 0.0);
    LuaAssert(L, st->xyz() == util::XYZ(0,0,0));
    LuaAssert(L, st->graphic() == "");
    LuaAssert(L, st->plane() == "");

    // Exceed the length limit, dropping first element.
    stp.clear();
    stp.set_action("walk");
    aq.add(12346, stp);
    aq.add(12347, stp);
    LuaAssert(L, aq.size() == 3);
    LuaAssert(L, aq.nth(0).id() == 0);
    LuaAssert(L, aq.nth(0).action() == "");
    LuaAssert(L, aq.nth(0).bits() == AnimStep::HAS_EVERYTHING);
    LuaAssert(L, aq.nth(1).id() == 12346);
    LuaAssert(L, aq.nth(2).id() == 12347);
    LuaAssert(L, aq.valid());

    // Test serialization and deserialization.
    aq.set_size_limit(5);
    aq.clear_steps();

    stp.clear();
    stp.set_action("walk");
    stp.set_xyz(util::XYZ(3,4,5));
    aq.add(12345, stp);

    stp.clear();
    stp.set_action("setgraphic");
    stp.set_graphic("banana");
    aq.add(12346, stp);

    stp.clear();
    stp.set_action("setfacing");
    stp.set_facing(301.0);
    aq.add(12347, stp);

    aq.serialize(&sb);
    aqds.deserialize(&sb);

    LuaAssert(L, aqds.size_limit() == 5);
    LuaAssert(L, aqds.size() == 4);

    LuaAssert(L, aqds.nth(0).id() == 0);
    LuaAssert(L, aqds.nth(0).bits() == AnimStep::HAS_EVERYTHING);
    LuaAssert(L, aqds.nth(0).action() == "");
    LuaAssert(L, aqds.nth(0).facing() == 0.0);
    LuaAssert(L, aqds.nth(0).xyz() == util::XYZ(0,0,0));
    LuaAssert(L, aqds.nth(0).graphic() == "");
    LuaAssert(L, aqds.nth(0).plane() == "");
    
    LuaAssert(L, aqds.nth(1).id() == 12345);
    LuaAssert(L, aqds.nth(1).bits() == AnimStep::HAS_XYZ);
    LuaAssert(L, aqds.nth(1).action() == "walk");
    LuaAssert(L, aqds.nth(1).facing() == 0.0);
    LuaAssert(L, aqds.nth(1).xyz() == util::XYZ(3,4,5));
    LuaAssert(L, aqds.nth(1).graphic() == "");
    LuaAssert(L, aqds.nth(1).plane() == "");

    LuaAssert(L, aqds.nth(2).id() == 12346);
    LuaAssert(L, aqds.nth(2).bits() == AnimStep::HAS_GRAPHIC);
    LuaAssert(L, aqds.nth(2).action() == "setgraphic");
    LuaAssert(L, aqds.nth(2).facing() == 0.0);
    LuaAssert(L, aqds.nth(2).xyz() == util::XYZ(3,4,5));
    LuaAssert(L, aqds.nth(2).graphic() == "banana");
    LuaAssert(L, aqds.nth(2).plane() == "");

    LuaAssert(L, aqds.nth(3).id() == 12347);
    LuaAssert(L, aqds.nth(3).bits() == AnimStep::HAS_FACING);
    LuaAssert(L, aqds.nth(3).action() == "setfacing");
    LuaAssert(L, aqds.nth(3).facing() == 301.0);
    LuaAssert(L, aqds.nth(3).xyz() == util::XYZ(3,4,5));
    LuaAssert(L, aqds.nth(3).graphic() == "banana");
    LuaAssert(L, aqds.nth(3).plane() == "");

    return 0;
}