const { ModelVersion, TrainingData } = require('../models');
const logger = require('../utils/logger');

const getModelStatus = async (req, res) => {
  try {
    const activeModels = await ModelVersion.findAll({
      where: { is_active: true },
      order: [['created_at', 'DESC']]
    });

    const modelStatus = {
      MODEL1: null,
      QUERYMODEL: null
    };

    activeModels.forEach(model => {
      if (model.model_type === 'MODEL1') {
        modelStatus.MODEL1 = {
          id: model.id,
          version: model.version,
          deployment_status: model.deployment_status,
          performance_metrics: model.performance_metrics,
          last_updated: model.updated_at
        };
      } else if (model.model_type === 'QUERYMODEL') {
        modelStatus.QUERYMODEL = {
          id: model.id,
          version: model.version,
          deployment_status: model.deployment_status,
          performance_metrics: model.performance_metrics,
          last_updated: model.updated_at
        };
      }
    });

    res.json({
      success: true,
      data: { modelStatus }
    });
  } catch (error) {
    logger.error('Get model status error:', error);
    res.status(500).json({
      success: false,
      error: 'Internal server error'
    });
  }
};

const getModelVersions = async (req, res) => {
  try {
    const { modelType, page = 1, limit = 10 } = req.query;

    const whereClause = {};
    if (modelType) whereClause.model_type = modelType;

    const models = await ModelVersion.findAndCountAll({
      where: whereClause,
      order: [['created_at', 'DESC']],
      limit: parseInt(limit),
      offset: (parseInt(page) - 1) * parseInt(limit)
    });

    res.json({
      success: true,
      data: {
        models: models.rows,
        pagination: {
          page: parseInt(page),
          limit: parseInt(limit),
          total: models.count,
          pages: Math.ceil(models.count / parseInt(limit))
        }
      }
    });
  } catch (error) {
    logger.error('Get model versions error:', error);
    res.status(500).json({
      success: false,
      error: 'Internal server error'
    });
  }
};

const createModelVersion = async (req, res) => {
  try {
    const {
      modelName,
      modelType,
      baseModel,
      fineTuningMethod,
      hyperparameters = {}
    } = req.body;

    if (!modelName || !modelType || !baseModel) {
      return res.status(400).json({
        success: false,
        error: 'Model name, type, and base model are required'
      });
    }

    const validModelTypes = ['MODEL1', 'QUERYMODEL'];
    if (!validModelTypes.includes(modelType)) {
      return res.status(400).json({
        success: false,
        error: 'Invalid model type'
      });
    }

    // Deactivate current active model of same type
    await ModelVersion.update(
      { is_active: false },
      { where: { model_type: modelType, is_active: true } }
    );

    const model = await ModelVersion.create({
      model_name: modelName,
      version: `v${Date.now()}`,
      model_type: modelType,
      base_model: baseModel,
      fine_tuning_method: fineTuningMethod,
      hyperparameters,
      deployment_status: 'training'
    });

    logger.info(`New model version created: ${model.id}`);

    res.status(201).json({
      success: true,
      data: { model }
    });
  } catch (error) {
    logger.error('Create model version error:', error);
    res.status(500).json({
      success: false,
      error: 'Internal server error'
    });
  }
};

const updateModelVersion = async (req, res) => {
  try {
    const { modelId } = req.params;
    const {
      deploymentStatus,
      performanceMetrics,
      modelPath,
      trainingLog
    } = req.body;

    const model = await ModelVersion.findByPk(modelId);

    if (!model) {
      return res.status(404).json({
        success: false,
        error: 'Model version not found'
      });
    }

    const updateData = {};
    if (deploymentStatus) updateData.deployment_status = deploymentStatus;
    if (performanceMetrics) updateData.performance_metrics = performanceMetrics;
    if (modelPath) updateData.model_path = modelPath;
    if (trainingLog) updateData.training_log = trainingLog;

    await model.update(updateData);

    logger.info(`Model version updated: ${modelId}`);

    res.json({
      success: true,
      data: { model }
    });
  } catch (error) {
    logger.error('Update model version error:', error);
    res.status(500).json({
      success: false,
      error: 'Internal server error'
    });
  }
};

const activateModel = async (req, res) => {
  try {
    const { modelId } = req.params;

    const model = await ModelVersion.findByPk(modelId);

    if (!model) {
      return res.status(404).json({
        success: false,
        error: 'Model version not found'
      });
    }

    // Deactivate other models of same type
    await ModelVersion.update(
      { is_active: false },
      { where: { model_type: model.model_type, is_active: true } }
    );

    // Activate this model
    await model.update({
      is_active: true,
      deployment_status: 'deployed'
    });

    logger.info(`Model activated: ${modelId}`);

    res.json({
      success: true,
      data: { model }
    });
  } catch (error) {
    logger.error('Activate model error:', error);
    res.status(500).json({
      success: false,
      error: 'Internal server error'
    });
  }
};

const getTrainingData = async (req, res) => {
  try {
    const { modelVersionId, dataType, page = 1, limit = 10 } = req.query;

    const whereClause = {};
    if (modelVersionId) whereClause.model_version_id = modelVersionId;
    if (dataType) whereClause.data_type = dataType;

    const trainingData = await TrainingData.findAndCountAll({
      where: whereClause,
      order: [['created_at', 'DESC']],
      limit: parseInt(limit),
      offset: (parseInt(page) - 1) * parseInt(limit)
    });

    res.json({
      success: true,
      data: {
        trainingData: trainingData.rows,
        pagination: {
          page: parseInt(page),
          limit: parseInt(limit),
          total: trainingData.count,
          pages: Math.ceil(trainingData.count / parseInt(limit))
        }
      }
    });
  } catch (error) {
    logger.error('Get training data error:', error);
    res.status(500).json({
      success: false,
      error: 'Internal server error'
    });
  }
};

module.exports = {
  getModelStatus,
  getModelVersions,
  createModelVersion,
  updateModelVersion,
  activateModel,
  getTrainingData
};