/**********************************************************************
 * File:        cube_reco_context.cpp
 * Description: Implementation of the Cube Recognition Context Class
 * Author:    Ahmad Abdulkader
 * Created:   2007
 *
 * (C) Copyright 2008, Google Inc.
 ** Licensed under the Apache License, Version 2.0 (the "License");
 ** you may not use this file except in compliance with the License.
 ** You may obtain a copy of the License at
 ** http://www.apache.org/licenses/LICENSE-2.0
 ** Unless required by applicable law or agreed to in writing, software
 ** distributed under the License is distributed on an "AS IS" BASIS,
 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 ** See the License for the specific language governing permissions and
 ** limitations under the License.
 *
 **********************************************************************/

#include <string>
#include <limits.h>

#include "cube_reco_context.h"

#include "classifier_factory.h"
#include "cube_tuning_params.h"
#include "dict.h"
#include "feature_bmp.h"
#include "tessdatamanager.h"
#include "tesseractclass.h"
#include "tess_lang_model.h"

namespace tesseract {

	/**
	 * Instantiate a CubeRecoContext object using a Tesseract object.
	 * CubeRecoContext will not take ownership of tess_obj, but will
	 * record the pointer to it and will make use of various Tesseract
	 * components (language model, flags, etc). Thus the caller should
	 * keep tess_obj alive so long as the instantiated CubeRecoContext is used.
	 */
	CubeRecoContext::CubeRecoContext(Tesseract *tess_obj) {
		tess_obj_ = tess_obj;
		lang_ = "";
		loaded_ = false;
		lang_mod_ = NULL;
		params_ = NULL;
		char_classifier_ = NULL;
		char_set_ = NULL;
		word_size_model_ = NULL;
		char_bigrams_ = NULL;
		word_unigrams_ = NULL;
		noisy_input_ = false;
		size_normalization_ = false;
	}

	CubeRecoContext::~CubeRecoContext() {
		delete char_classifier_;
		char_classifier_ = NULL;

		delete word_size_model_;
		word_size_model_ = NULL;

		delete char_set_;
		char_set_ = NULL;

		delete char_bigrams_;
		char_bigrams_ = NULL;

		delete word_unigrams_;
		word_unigrams_ = NULL;

		delete lang_mod_;
		lang_mod_ = NULL;

		delete params_;
		params_ = NULL;
	}

	/**
	 * Returns the path of the data files by looking up the TESSDATA_PREFIX
	 * environment variable and appending a "tessdata" directory to it
	 */
	bool CubeRecoContext::GetDataFilePath(string *path) const {
		*path = tess_obj_->datadir.string();
		return true;
	}

	/**
	 * The object initialization function that loads all the necessary
	 * components of a RecoContext.  TessdataManager is used to load the
	 * data from [lang].traineddata file.  If TESSDATA_CUBE_UNICHARSET
	 * component is present, Cube will be instantiated with the unicharset
	 * specified in this component and the corresponding dictionary
	 * (TESSDATA_CUBE_SYSTEM_DAWG), and will map Cube's unicharset to
	 * Tesseract's. Otherwise, TessdataManager will assume that Cube will
	 * be using Tesseract's unicharset and dawgs, and will load the
	 * unicharset from the TESSDATA_UNICHARSET component and will load the
	 * dawgs from TESSDATA_*_DAWG components.
	 */
	bool CubeRecoContext::Load(TessdataManager *tessdata_manager,
		UNICHARSET *tess_unicharset) {
		ASSERT_HOST(tess_obj_ != NULL);
		tess_unicharset_ = tess_unicharset;
		string data_file_path;

		// Get the data file path.
		if (GetDataFilePath(&data_file_path) == false) {
			fprintf(stderr, "Unable to get data file path\n");
			return false;
		}

		// Get the language from the Tesseract object.
		lang_ = tess_obj_->lang.string();

		// Create the char set.
		if ((char_set_ =
			CharSet::Create(tessdata_manager, tess_unicharset)) == NULL) {
			fprintf(stderr, "Cube ERROR (CubeRecoContext::Load): unable to load "
				"CharSet\n");
			return false;
		}
		// Create the language model.
		string lm_file_name = data_file_path + lang_ + ".cube.lm";
		string lm_params;
		if (!CubeUtils::ReadFileToString(lm_file_name, &lm_params)) {
			fprintf(stderr, "Cube ERROR (CubeRecoContext::Load): unable to read cube "
				"language model params from %s\n", lm_file_name.c_str());
			return false;
		}
		lang_mod_ = new TessLangModel(lm_params, data_file_path,
			tess_obj_->getDict().load_system_dawg,
			tessdata_manager, this);

		// Create the optional char bigrams object.
		char_bigrams_ = CharBigrams::Create(data_file_path, lang_);

		// Create the optional word unigrams object.
		word_unigrams_ = WordUnigrams::Create(data_file_path, lang_);

		// Create the optional size model.
		word_size_model_ = WordSizeModel::Create(data_file_path, lang_,
			char_set_, Contextual());

		// Load tuning params.
		params_ = CubeTuningParams::Create(data_file_path, lang_);
		if (params_ == NULL) {
			fprintf(stderr, "Cube ERROR (CubeRecoContext::Load): unable to read "
				"CubeTuningParams from %s\n", data_file_path.c_str());
			return false;
		}

		// Create the char classifier.
		char_classifier_ = CharClassifierFactory::Create(data_file_path, lang_,
			lang_mod_, char_set_,
			params_);
		if (char_classifier_ == NULL) {
			fprintf(stderr, "Cube ERROR (CubeRecoContext::Load): unable to load "
				"CharClassifierFactory object from %s\n", data_file_path.c_str());
			return false;
		}

		loaded_ = true;

		return true;
	}

	/** Creates a CubeRecoContext object using a tesseract object */
	CubeRecoContext * CubeRecoContext::Create(Tesseract *tess_obj,
		TessdataManager *tessdata_manager,
		UNICHARSET *tess_unicharset) {
		// create the object
		CubeRecoContext *cntxt = new CubeRecoContext(tess_obj);
		// load the necessary components
		if (cntxt->Load(tessdata_manager, tess_unicharset) == false) {
			fprintf(stderr, "Cube ERROR (CubeRecoContext::Create): unable to init "
				"CubeRecoContext object\n");
			delete cntxt;
			return NULL;
		}
		// success
		return cntxt;
	}
}  // tesseract}