/**
 * Copyright (c) 2026 Dominic Masters
 * 
 * This software is released under the MIT License.
 * https://opensource.org/licenses/MIT
 */

#include "modulecamera.h"
#include "assert/assert.h"
#include "display/camera/camera.h"
#include "util/memory.h"
#include "util/string.h"

void moduleCamera(scriptcontext_t *context) {
  assertNotNull(context, "Context cannot be NULL.");

  // Create metatable for camera structure.
  if(luaL_newmetatable(context->luaState, "camera_mt")) {
    // Metatable methods
    lua_pushcfunction(context->luaState, moduleCameraIndex);
    lua_setfield(context->luaState, -2, "__index");
    lua_pushcfunction(context->luaState, moduleCameraNewIndex);
    lua_setfield(context->luaState, -2, "__newindex");
    lua_pop(context->luaState, 1);
  }

  // Definitions
  #define MODULE_CAMERA_SCRIPT_LEN 64
  char_t buffer[MODULE_CAMERA_SCRIPT_LEN];
  #define MODULE_CAMERA_DEF(str, val) \
    snprintf( \
      buffer, \
      MODULE_CAMERA_SCRIPT_LEN, \
      "%s = %d", \
      str, \
      val \
    ); \
    scriptContextExec(context, buffer);
  
  MODULE_CAMERA_DEF(
    "CAMERA_PROJECTION_TYPE_PERSPECTIVE",
    CAMERA_PROJECTION_TYPE_PERSPECTIVE
  );
  MODULE_CAMERA_DEF(
    "CAMERA_PROJECTION_TYPE_PERSPECTIVE_FLIPPED",
    CAMERA_PROJECTION_TYPE_PERSPECTIVE_FLIPPED
  );
  MODULE_CAMERA_DEF(
    "CAMERA_PROJECTION_TYPE_ORTHOGRAPHIC",
    CAMERA_PROJECTION_TYPE_ORTHOGRAPHIC
  );

  MODULE_CAMERA_DEF(
    "CAMERA_VIEW_TYPE_MATRIX",
    CAMERA_VIEW_TYPE_MATRIX
  );
  MODULE_CAMERA_DEF(
    "CAMERA_VIEW_TYPE_LOOKAT",
    CAMERA_VIEW_TYPE_LOOKAT
  );
  MODULE_CAMERA_DEF(
    "CAMERA_VIEW_TYPE_2D",
    CAMERA_VIEW_TYPE_2D
  );
  MODULE_CAMERA_DEF(
    "CAMERA_VIEW_TYPE_LOOKAT_PIXEL_PERFECT",
    CAMERA_VIEW_TYPE_LOOKAT_PIXEL_PERFECT
  );

  // Methods
  lua_register(context->luaState, "cameraCreate", moduleCameraCreate);
  lua_register(context->luaState, "cameraPushMatrix", moduleCameraPushMatrix);
  lua_register(context->luaState, "cameraPopMatrix", moduleCameraPopMatrix);
}

int moduleCameraCreate(lua_State *L) {
  assertNotNull(L, "Lua state cannot be NULL.");

  scriptcontext_t *context = *(scriptcontext_t **)lua_getextraspace(L);
  assertNotNull(context, "Script context cannot be NULL.");

  // If we are provided a projection type, use it.
  cameraprojectiontype_t projType = CAMERA_PROJECTION_TYPE_PERSPECTIVE;
  if(lua_gettop(L) >= 1) {
    projType = (cameraprojectiontype_t)luaL_checkinteger(L, 1);
  }

  // Create camera that Lua will own
  camera_t *cam = (camera_t *)lua_newuserdata(L, sizeof(camera_t));
  memoryZero(cam, sizeof(camera_t));

  // Set metatable
  luaL_getmetatable(L, "camera_mt");
  lua_setmetatable(L, -2);

  // Init camera
  switch(projType) {
    case CAMERA_PROJECTION_TYPE_PERSPECTIVE:
    case CAMERA_PROJECTION_TYPE_PERSPECTIVE_FLIPPED:
      cameraInitPerspective(cam);
      cam->projType = projType;
      break;

    case CAMERA_PROJECTION_TYPE_ORTHOGRAPHIC:
      cameraInitOrthographic(cam);
      cam->projType = projType;
      break;

    default:
      luaL_error(L, "Invalid camera projection type specified.");
      break;
  }

  return 1;
}

int moduleCameraPushMatrix(lua_State *L) {
  assertNotNull(L, "Lua state cannot be NULL.");
  assertTrue(lua_gettop(L) >= 1, "cameraPushMatrix requires 1 arg.");
  assertTrue(lua_isuserdata(L, 1), "cameraPushMatrix arg must be userdata.");

  // Camera should be provided (pointer to camera_t).
  camera_t *cam = (camera_t *)luaL_checkudata(L, 1, "camera_mt");
  assertNotNull(cam, "Camera pointer cannot be NULL.");

  cameraPushMatrix(cam);
  return 0;
}

int moduleCameraPopMatrix(lua_State *L) {
  assertNotNull(L, "Lua state cannot be NULL.");
  cameraPopMatrix();
  return 0;
}

int moduleCameraIndex(lua_State *l) {
  assertNotNull(l, "Lua state cannot be NULL.");

  const char_t *key = luaL_checkstring(l, 2);
  assertStrLenMin(key, 1, "Key cannot be empty.");

  camera_t *cam = (camera_t *)luaL_checkudata(l, 1, "camera_mt");
  assertNotNull(cam, "Camera pointer cannot be NULL.");

  if(stringCompare(key, "near") == 0) {
    lua_pushnumber(l, cam->nearClip);
    return 1;
  } else if(stringCompare(key, "far") == 0) {
    lua_pushnumber(l, cam->farClip);
    return 1;
  } else if(stringCompare(key, "nearClip") == 0) {
    lua_pushnumber(l, cam->nearClip);
    return 1;
  } else if(stringCompare(key, "farClip") == 0) {
    lua_pushnumber(l, cam->farClip);
    return 1;
  }

  // Perspective relative values
  if(cam->projType == CAMERA_PROJECTION_TYPE_ORTHOGRAPHIC) {
    if(stringCompare(key, "left") == 0) {
      lua_pushnumber(l, cam->orthographic.left);
      return 1;
    } else if(stringCompare(key, "right") == 0) {
      lua_pushnumber(l, cam->orthographic.right);
      return 1;
    } else if(stringCompare(key, "top") == 0) {
      lua_pushnumber(l, cam->orthographic.top);
      return 1;
    } else if(stringCompare(key, "bottom") == 0) {
      lua_pushnumber(l, cam->orthographic.bottom);
      return 1;
    }
  } else if(
    cam->projType == CAMERA_PROJECTION_TYPE_PERSPECTIVE ||
    cam->projType == CAMERA_PROJECTION_TYPE_PERSPECTIVE_FLIPPED
  ) {
    if(stringCompare(key, "fov") == 0) {
      lua_pushnumber(l, cam->perspective.fov);
      return 1;
    }
  }

  // View type relative values.
  if(cam->viewType == CAMERA_VIEW_TYPE_MATRIX) {

  } else if(cam->viewType == CAMERA_VIEW_TYPE_LOOKAT) {
    if(stringCompare(key, "position") == 0) {
      vec3 *v = (vec3 *)lua_newuserdata(l, sizeof(vec3));
      memoryCopy(v, &cam->lookat.position, sizeof(vec3));
      luaL_getmetatable(l, "vec3_mt");
      lua_setmetatable(l, -2);
      return 1;
    } else if(stringCompare(key, "target") == 0) {
      vec3 *v = (vec3 *)lua_newuserdata(l, sizeof(vec3));
      memoryCopy(v, &cam->lookat.target, sizeof(vec3));
      luaL_getmetatable(l, "vec3_mt");
      lua_setmetatable(l, -2);
      return 1;
    } else if(stringCompare(key, "up") == 0) {
      vec3 *v = (vec3 *)lua_newuserdata(l, sizeof(vec3));
      memoryCopy(v, &cam->lookat.up, sizeof(vec3));
      luaL_getmetatable(l, "vec3_mt");
      lua_setmetatable(l, -2);
      return 1;
    }
  } else if(cam->viewType == CAMERA_VIEW_TYPE_LOOKAT_PIXEL_PERFECT) {

  } else if(cam->viewType == CAMERA_VIEW_TYPE_2D) {

  }
  
  lua_pushnil(l);
  return 1;
}

int moduleCameraNewIndex(lua_State *l) {
  assertNotNull(l, "Lua state cannot be NULL.");
  
  const char_t *key = luaL_checkstring(l, 2);
  assertStrLenMin(key, 1, "Key cannot be empty.");

  camera_t *cam = (camera_t *)luaL_checkudata(l, 1, "camera_mt");
  assertNotNull(cam, "Camera pointer cannot be NULL.");

  if(stringCompare(key, "near") == 0 || stringCompare(key, "nearClip") == 0) {
    if(!lua_isnumber(l, 3)) {
      luaL_error(l, "Camera near clip must be a number.");
    }
    cam->nearClip = (float_t)lua_tonumber(l, 3);
    return 0;
  }
  
  if(stringCompare(key, "far") == 0 || stringCompare(key, "farClip") == 0) {
    if(!lua_isnumber(l, 3)) {
      luaL_error(l, "Camera far clip must be a number.");
    }
    cam->farClip = (float_t)lua_tonumber(l, 3);
    return 0;
  }

  // Perspective relative values
  if(cam->projType == CAMERA_PROJECTION_TYPE_ORTHOGRAPHIC) {
    if(stringCompare(key, "left") == 0) {
      if(!lua_isnumber(l, 3)) {
        luaL_error(l, "Camera orthographic left must be a number.");
      }
      cam->orthographic.left = (float_t)lua_tonumber(l, 3);
      return 0;
    }

    if(stringCompare(key, "right") == 0) {
      if(!lua_isnumber(l, 3)) {
        luaL_error(l, "Camera orthographic right must be a number.");
      }
      cam->orthographic.right = (float_t)lua_tonumber(l, 3);
      return 0;
    }

    if(stringCompare(key, "top") == 0) {
      if(!lua_isnumber(l, 3)) {
        luaL_error(l, "Camera orthographic top must be a number.");
      }
      cam->orthographic.top = (float_t)lua_tonumber(l, 3);
      return 0;
    }
    
    if(stringCompare(key, "bottom") == 0) {
      if(!lua_isnumber(l, 3)) {
        luaL_error(l, "Camera orthographic bottom must be a number.");
      }
      cam->orthographic.bottom = (float_t)lua_tonumber(l, 3);
      return 0;
    }
  } else if(
    cam->projType == CAMERA_PROJECTION_TYPE_PERSPECTIVE ||
    cam->projType == CAMERA_PROJECTION_TYPE_PERSPECTIVE_FLIPPED
  ) {
    if(stringCompare(key, "fov") == 0) {
      if(!lua_isnumber(l, 3)) {
        luaL_error(l, "Camera perspective FOV must be a number.");
      }
      cam->perspective.fov = (float_t)lua_tonumber(l, 3);
      return 0;
    }
  }

  if(cam->viewType == CAMERA_VIEW_TYPE_LOOKAT) {
    if(stringCompare(key, "position") == 0) {
      vec3 *v = (vec3 *)luaL_checkudata(l, 3, "vec3_mt");
      assertNotNull(v, "Vec3 pointer cannot be NULL.");
      memoryCopy(&cam->lookat.position, v, sizeof(vec3));
      return 0;
    } else if(stringCompare(key, "target") == 0) {
      vec3 *v = (vec3 *)luaL_checkudata(l, 3, "vec3_mt");
      assertNotNull(v, "Vec3 pointer cannot be NULL.");
      memoryCopy(&cam->lookat.target, v, sizeof(vec3));
      return 0;
    } else if(stringCompare(key, "up") == 0) {
      vec3 *v = (vec3 *)luaL_checkudata(l, 3, "vec3_mt");
      assertNotNull(v, "Vec3 pointer cannot be NULL.");
      memoryCopy(&cam->lookat.up, v, sizeof(vec3));
      return 0;
    }
  }

  return 0;
}