#ifndef CHARACTER_CLASS
#define CHARACTER_CLASS
#include <vector>
#include <string>
#include <map>
#include <unordered_map>
#include <algorithm>
#include "t.h"
#include "Rig.h"
#include "Object.h"
#include "Animator.h"
#include "CharacterAction.h"

class Character;
class CharacterManager;
class CharacterMind;
class Ragdoll;
class Physics;
class p;

// The physical side of a character: where it is, its physics body, its animation,
// and carrying out whatever actions its mind sends it.
class CharacterBody : public t_package {
public:
    Rig* rig = nullptr;
    p* physics = nullptr;          // made by Character::CreatePhysicsBody, its box is t's scale

    std::vector<Animator*> animators;
    Animator* animator = nullptr;      // the base layer, always fully on: standing idle
    Animator* walkAnimator = nullptr;  // on top of the idle, faded in while walking
    Animator* actionAnimator = nullptr;   // one-shots on top of both, see PlayAction

    float walkSpeed = 2.34f;       // m/s on flat ground
    float turnSpeed = 12.0f;       // how quickly it turns to face where it's walking
    float walkFadeSpeed = 8.0f;    // how quickly it fades between idle and walking

    CharacterBody() {
        animator = AddAnimator(0);
        animator->blendWeight = 1.0f;  // base always fully visible
    }

    Animator* AddAnimator(int weight) {
        Animator* a = new Animator();
        a->weight = weight;
        if (rig) a->SetRig(rig);
        animators.push_back(a);
        std::sort(animators.begin(), animators.end(),
            [](Animator* a, Animator* b) { return a->weight < b->weight; });
        return a;
    }

    // The skinning matrices for this frame, from every animator layered together. Worked out in Step.
    // Base (weight 0) is the foundation; each higher-weight animator blends in by its blendWeight,
    // but only on the bones its animation has tracks for, so an arm-only clip leaves the legs walking.
    const std::vector<glm::mat4>& GetBlendedBoneMatrices() const {
        return blendedBones.empty() ? animator->GetFinalBoneMatrices() : blendedBones;
    }

    void SetRig(Rig* r) {
        rig = r;
        for (Animator* a : animators)
            a->SetRig(r);
    }

    void SetAnimation(Animation* anim) {
        animator->SetAnimation(anim);
        animator->PlayAnimation();
        animator->blendWeight = 1.0f;  // base never blends, always instant
    }

    // Plays an animation once on top of everything else. Starts over if it's already playing.
    void PlayAction(Animation* anim) {
        if (!anim)
            return;
        if (!actionAnimator) {
            actionAnimator = AddAnimator(2);
            actionAnimator->blendDuration = 0.1f;
        }
        actionAnimator->loops = false;
        actionAnimator->SetAnimation(anim);
        actionAnimator->PlayAnimation();
    }

    // The loop played while walking. It keeps running underneath so it picks up mid-stride.
    void SetWalkAnimation(Animation* anim) {
        if (!walkAnimator)
            walkAnimator = AddAnimator(1);
        walkAnimator->loops = true;
        walkAnimator->SetAnimation(anim);
        walkAnimator->PlayAnimation();
        walkAnimator->blendWeight = walkBlend;
    }

    // Carries out one action. Movement actions only count for the frame they arrive in.
    void Perform(const CharacterAction& action);

    // Pushes the physics body toward walking speed along wherever it faces, from this frame's Move action.
    // speedFactor scales it, 0 stops it.
    void ApplyMovement(bool grounded, float speedFactor, float dt, float referenceDt);

    // Turning and animation
    void Step(float dt);

    void SetWalking(bool walking);
    glm::vec3 GetForwardDirection() const;

private:
    glm::vec3 wishDirection = glm::vec3(0.0f);   // from this frame's Move action
    glm::vec3 turnDirection = glm::vec3(0.0f);   // where it's turning to face, kept after it stops
    bool walking = false;
    float walkBlend = 0.0f;                      // 0 = idle, 1 = walking
    std::vector<glm::mat4> blendedBones;

    // Per (base clip, layer clip): bone name -> what turns the layer's track into one relative to the bone's
    // real parent. Only bones whose parent differs between the two files have an entry.
    std::map<std::pair<const Animation*, const Animation*>, std::unordered_map<std::string, glm::mat4>> parentCorrections;

    void BlendBones(const AssimpNodeData& node, const glm::mat4& parentTransform);
    const std::unordered_map<std::string, glm::mat4>& GetParentCorrections(const Animation* layer);
};

class Character : public Object, public Renderable {
public:
    CharacterMind* mind = nullptr;   // what decides its actions, nullptr does nothing
    CharacterBody* body = nullptr;
    Ragdoll* ragdoll = nullptr;   // when set, physics drives the rig instead of the animators
    SurfaceTexture surface;
    glm::vec4 colorOverride = glm::vec4(0.0f);  // rgb + strength (0 = keep the rig's own texture)
    float    visualScale = 1.4f;  // rig is ~1.8 tall natively; its physics box is 2.5
    float    metallic = 0.0f;
    float    roughness = 0.7f;
    float    ao = 1.0f;

    // Asks the mind for this frame's actions and hands them to the body
    void Think();

    glm::vec3 GetForwardDirection() const { return body->GetForwardDirection(); }
    void EnableRagdoll(Physics& physics);

    // The box physics moves the character around with, sized by body->t's scale
    void CreatePhysicsBody(Physics& physics, float massKg);

    // Its physics body's group, so it never collides with anything else of its own
    int GetCollisionGroup();

    Character();
    void Render(Shader& shader) override;
    bool GetWorldBounds(BoundingBox& bounds) const override;

    void Step(float dt) {
        if (ragdoll) return;
        body->Step(dt);
    }

private:
    glm::mat4 GetRigMatrix() const;

    int collisionGroup = 0;
    std::vector<CharacterAction> pendingActions;
};
#endif