'use strict';

/**
 * Module dependencies
 */

// Public node modules.
const _ = require('lodash');

// Node.js core
const path = require('path');

/*
 * Set of utils for models
 */

module.exports = {

  /**
   * Initialize to prevent some mistakes
   */

  initialize: cb => {
    cb();
  },

  /**
   * Find primary key per ORM
   */

  getPK: function (collectionIdentity, collection, models) {
    if (_.isString(collectionIdentity)) {
      const ORM = this.getORM(collectionIdentity);

      try {
        const GraphQLFunctions = require(path.resolve(strapi.config.appPath, 'node_modules', 'strapi-' + ORM, 'lib', 'utils'));

        if (!_.isUndefined(GraphQLFunctions)) {
          return GraphQLFunctions.getPK(collectionIdentity, collection, models || strapi.models);
        }
      } catch (err) {
        return undefined;
      }
    }

    return undefined;
  },

  /**
   * Find primary key per ORM
   */

  getCount: function (collectionIdentity) {
    if (_.isString(collectionIdentity)) {
      const ORM = this.getORM(collectionIdentity);

      try {
        const ORMFunctions = require(path.resolve(strapi.config.appPath, 'node_modules', 'strapi-' + ORM, 'lib', 'utils'));

        if (!_.isUndefined(ORMFunctions)) {
          return ORMFunctions.getCount(collectionIdentity);
        }
      } catch (err) {
        return undefined;
      }
    }

    return undefined;
  },

  /**
   * Find relation nature with verbose
   */

  getNature: (association, key, models, currentModelName) => {
    try {
      const types = {
        current: '',
        other: ''
      };

      if (_.isUndefined(models)) {
        models = association.plugin ? strapi.plugins[association.plugin].models : strapi.models;
      }

      if (association.hasOwnProperty('via') && association.hasOwnProperty('collection')) {
        const relatedAttribute = models[association.collection].attributes[association.via];

        types.current = 'collection';

        if (relatedAttribute.hasOwnProperty('collection') && relatedAttribute.hasOwnProperty('via')) {
          types.other = 'collection';
        } else if (relatedAttribute.hasOwnProperty('collection') && !relatedAttribute.hasOwnProperty('via')) {
          types.other = 'collectionD';
        } else if (relatedAttribute.hasOwnProperty('model')) {
          types.other = 'model';
        } else if (relatedAttribute.hasOwnProperty('key')) {
          types.other = 'morphTo';
        }
      } else if (association.hasOwnProperty('via') && association.hasOwnProperty('model')) {
        types.current = 'modelD';

        // We have to find if they are a model linked to this key
        _.forIn(_.omit(models, currentModelName || ''), model => {
          _.forIn(model.attributes, attribute => {
            if (attribute.hasOwnProperty('via') && attribute.via === key && attribute.hasOwnProperty('collection')) {
              types.other = 'collection';

              // Break loop
              return false;
            } else if (attribute.hasOwnProperty('model')) {
              types.other = 'model';

              // Break loop
              return false;
            } else if (attribute.hasOwnProperty('key')) {
              types.other = 'morphTo';

              // Break loop
              return false;
            }
          });
        });
      } else if (association.hasOwnProperty('model')) {
        types.current = 'model';

        // We have to find if they are a model linked to this key
        _.forIn(models, model => {
          _.forIn(model.attributes, attribute => {
            if (attribute.hasOwnProperty('via') && attribute.via === key) {
              if (attribute.hasOwnProperty('collection')) {
                types.other = 'collection';

                // Break loop
                return false;
              } else if (attribute.hasOwnProperty('model')) {
                types.other = 'modelD';

                // Break loop
                return false;
              }
            }
          });
        });
      } else if (association.hasOwnProperty('collection')) {
        types.current = 'collectionD';

        // We have to find if they are a model linked to this key
        _.forIn(models, model => {
          _.forIn(model.attributes, attribute => {
            if (attribute.hasOwnProperty('via') && attribute.via === key) {
              if (attribute.hasOwnProperty('collection')) {
                types.other = 'collection';

                // Break loop
                return false;
              } else if (attribute.hasOwnProperty('model')) {
                types.other = 'modelD';

                // Break loop
                return false;
              }
            }
          });
        });
      } else if (association.hasOwnProperty('key')) {
        types.current = 'morphTo';

        const flattenedPluginsModels = Object.keys(strapi.plugins).reduce((acc, current) => {
          Object.keys(strapi.plugins[current].models).forEach((model) => {
            acc[`${current}_${model}`] = strapi.plugins[current].models[model];
          });

          return acc;
        }, {});

        const allModels = _.merge({}, strapi.models, flattenedPluginsModels);

        // We have to find if they are a model linked to this key
        _.forIn(allModels, model => {
          _.forIn(model.attributes, attribute => {
            if (attribute.hasOwnProperty('via') && attribute.via === key) {
              if (attribute.hasOwnProperty('collection')) {
                types.other = 'collection';

                // Break loop
                return false;
              } else if (attribute.hasOwnProperty('model')) {
                types.other = 'model';

                // Break loop
                return false;
              }
            }
          });
        });
      }

      if (types.current === 'collection' && types.other === 'morphTo') {
        return {
          nature: 'manyToMorph',
          verbose: 'morphMany'
        };
      } else if (types.current === 'modelD' && types.other === 'morphTo') {
        return {
          nature: 'oneToMorph',
          verbose: 'morphOne'
        };
      } else if (types.current === 'morphTo' && types.other === 'collection') {
        return {
          nature: 'morphToMany',
          verbose: 'belongsToMorph'
        };
      } else if (types.current === 'morphTo' && types.other === 'model') {
        return {
          nature: 'morphToOne',
          verbose: 'belongsToManyMorph'
        };
      } else if (types.current === 'modelD' && types.other === 'model') {
        return {
          nature: 'oneToOne',
          verbose: 'belongsTo'
        };
      } else if (types.current === 'model' && types.other === 'modelD') {
        return {
          nature: 'oneToOne',
          verbose: 'hasOne'
        };
      } else if ((types.current === 'model' || types.current === 'modelD') && types.other === 'collection') {
        return {
          nature: 'manyToOne',
          verbose: 'belongsTo'
        };
      } else if (types.current === 'modelD' && types.other === 'collection') {
        return {
          nature: 'oneToMany',
          verbose: 'hasMany'
        };
      } else if (types.current === 'collection' && types.other === 'model') {
        return {
          nature: 'oneToMany',
          verbose: 'hasMany'
        };
      } else if (types.current === 'collection' && types.other === 'collection') {
        return {
          nature: 'manyToMany',
          verbose: 'belongsToMany'
        };
      } else if (types.current === 'collectionD' && types.other === 'collection' || types.current === 'collection' && types.other === 'collectionD') {
        return {
          nature: 'manyToMany',
          verbose: 'belongsToMany'
        };
      } else if (types.current === 'collectionD' && types.other === '') {
        return {
          nature: 'manyWay',
          verbose: 'belongsToMany'
        };
      } else if (types.current === 'model' && types.other === '') {
        return {
          nature: 'oneWay',
          verbose: 'belongsTo'
        };
      }

      return undefined;
    } catch (e) {
      strapi.log.error(`Something went wrong in the model \`${_.upperFirst(currentModelName)}\` with the attribute \`${key}\``);
      strapi.stop();
    }
  },

  /**
   * Return ORM used for this collection.
   */

  getORM: collectionIdentity => {
    return _.get(strapi.models, collectionIdentity.toLowerCase() + '.orm');
  },

  /**
   * Define associations key to models
   */

  defineAssociations: function (model, definition, association, key) {
    try {
      // Initialize associations object
      if (definition.associations === undefined) {
        definition.associations = [];
      }

      // Exclude non-relational attribute
      if (!association.hasOwnProperty('collection') && !association.hasOwnProperty('model') && !association.hasOwnProperty('key')) {
        return undefined;
      }

      // Get relation nature
      const infos = this.getNature(association, key, undefined, model.toLowerCase());
      const details = _.get(strapi.models, `${association.model || association.collection}.attributes.${association.via}`, {});

      // Build associations object
      if (association.hasOwnProperty('collection')) {
        definition.associations.push({
          alias: key,
          type: 'collection',
          collection: association.collection,
          via: association.via || undefined,
          nature: infos.nature,
          autoPopulate: _.get(association, 'autoPopulate', true),
          dominant: details.dominant !== true,
          plugin: association.plugin || undefined,
          where: details.where,
        });
      } else if (association.hasOwnProperty('model')) {
        definition.associations.push({
          alias: key,
          type: 'model',
          model: association.model,
          via: association.via || undefined,
          nature: infos.nature,
          autoPopulate: _.get(association, 'autoPopulate', true),
          dominant: details.dominant !== true,
          plugin: association.plugin || undefined,
          where: details.where,
        });
      } else if (association.hasOwnProperty('key')) {
        const pluginsModels = Object.keys(strapi.plugins).reduce((acc, current) => {
          Object.keys(strapi.plugins[current].models).forEach((entity) => {
            Object.keys(strapi.plugins[current].models[entity].attributes).forEach((attribute) => {
              const attr = strapi.plugins[current].models[entity].attributes[attribute];
              if (
                (attr.collection || attr.model || '').toLowerCase() === model.toLowerCase() &&
                strapi.plugins[current].models[entity].globalId !== definition.globalId
              ) {
                acc.push(strapi.plugins[current].models[entity].globalId);
              }
            });
          });

          return acc;
        }, []);

        const appModels = Object.keys(strapi.models).reduce((acc, entity) => {
          Object.keys(strapi.models[entity].attributes).forEach((attribute) => {
            const attr = strapi.models[entity].attributes[attribute];

            if (
              (attr.collection || attr.model || '').toLowerCase() === model.toLowerCase() &&
              strapi.models[entity].globalId !== definition.globalId
            ) {
              acc.push(strapi.models[entity].globalId);
            }
          });

          return acc;
        }, []);

        const models = _.uniq(appModels.concat(pluginsModels));

        definition.associations.push({
          alias: key,
          type: 'collection',
          related: models,
          nature: infos.nature,
          autoPopulate: _.get(association, 'autoPopulate', true),
          key: association.key,
        });
      }
    } catch (e) {
      strapi.log.error(`Something went wrong in the model \`${_.upperFirst(model)}\` with the attribute \`${key}\``);
      strapi.stop();
    }
  },

  getVia: (attribute, association) => {
    return _.findKey(strapi.models[association.model || association.collection].attributes, {via: attribute});
  },

  convertParams: (entity, params) => {
    if (!entity) {
      throw new Error('You can\'t call the convert params method without passing the model\'s name as a first argument.');
    }

    const model = entity.toLowerCase();

    const models = _.assign(_.clone(strapi.models), Object.keys(strapi.plugins).reduce((acc, current) => {
      _.assign(acc, _.get(strapi.plugins[current], ['models'], {}));
      return acc;
    }, {}));

    if (!models.hasOwnProperty(model)) {
      return this.log.error(`The model ${model} can't be found.`);
    }

    const connector = models[model].orm;

    if (!connector) {
      throw new Error(`Impossible to determine the ORM used for the model ${model}.`);
    }

    const convertor = strapi.hook[connector].load().getQueryParams;
    const convertParams = {
      where: {},
      sort: '',
      start: 0,
      limit: 100
    };

    _.forEach(params, (value, key)  => {
      let result;

      if (_.includes(['_start', '_limit'], key)) {
        result = convertor(value, key);
      } else if (key === '_sort') {
        const [attr, order] = value.split(':');
        result = convertor(order, key, attr);
      } else {
        const suffix = key.split('_');

        let type;

        if (_.includes(['ne', 'lt', 'gt', 'lte', 'gte'], _.last(suffix))) {
          type = `_${_.last(suffix)}`;
          key = _.dropRight(suffix).join('_');
        } else {
          type = '=';
        }

        result = convertor(value, type, key);
      }

      _.set(convertParams, result.key, result.value);
    });

    return convertParams;
  }
};