const db = require('../db/models');
const UsersDBApi = require('../db/api/users');
const { createEntityService } = require('../factories/service.factory');
const {
  assertCreateOptions,
  assertIdOptions,
  assertUpdateOptions,
} = require('../contracts/entity-options');
const ValidationError = require('./notifications/errors/validation');
const config = require('../config');
const AuthService = require('./auth');
const { logger } = require('../utils/logger');
const AccessPolicy = require('./access-policy');

// Generate base service from factory
const BaseUsersService = createEntityService(UsersDBApi, {
  entityName: 'Users',
});

/**
 * Users service with email invitation functionality
 * Extends factory-generated service with custom user logic
 */
class UsersService extends BaseUsersService {
  static normalizeIdArray(value) {
    if (!Array.isArray(value)) return [];
    return value
      .map((item) => {
        if (typeof item === 'string') return item;
        if (item && typeof item === 'object') return item.id || item.value;
        return null;
      })
      .filter(Boolean);
  }

  static normalizeRoleId(value) {
    if (!value) return null;
    if (typeof value === 'string') return value;
    if (typeof value === 'object') return value.id || value.value || null;
    return null;
  }

  static async createProductionPresentationAccessForPublicUser({
    user,
    data,
    currentUser,
    transaction,
  }) {
    if (!user?.id) return;

    await db.production_presentation_access.destroy({
      where: { userId: user.id },
      transaction,
    });

    const selectedProjectIds = this.normalizeIdArray(
      data.allowed_private_production_project_ids,
    );

    const roleId = this.normalizeRoleId(data.app_role);
    if (!selectedProjectIds.length || !roleId) return;

    const role = await db.roles.findByPk(roleId, { transaction });
    if (role?.name !== 'Public') return;

    const privateProjects = await db.projects.findAll({
      where: {
        id: {
          [db.Sequelize.Op.in]: selectedProjectIds,
        },
        production_presentation_visibility: 'private',
      },
      attributes: ['id'],
      transaction,
    });

    if (!privateProjects.length) return;

    const now = new Date();
    await db.production_presentation_access.bulkCreate(
      privateProjects.map((project) => ({
        projectId: project.id,
        userId: user.id,
        createdById: currentUser?.id || null,
        updatedById: currentUser?.id || null,
        createdAt: now,
        updatedAt: now,
      })),
      { ignoreDuplicates: true, transaction },
    );
  }

  static async assertPublicUserHasNoAdminPermissions(data, transaction) {
    const roleId = this.normalizeRoleId(data.app_role);
    if (!roleId) return false;

    const role = await db.roles.findByPk(roleId, { transaction });
    if (role?.name !== 'Public') return false;

    const customPermissions = this.normalizeIdArray(data.custom_permissions);
    if (customPermissions.length > 0) {
      throw new ValidationError(
        'Public users cannot receive custom permissions',
      );
    }

    return true;
  }

  static async updateProductionPresentationAccessForPublicUser({
    user,
    data,
    currentUser,
    transaction,
  }) {
    if (!user?.id) return;

    await db.production_presentation_access.destroy({
      where: { userId: user.id },
      transaction,
    });

    await this.createProductionPresentationAccessForPublicUser({
      user,
      data,
      currentUser,
      transaction,
    });
  }

  /**
   * Create user with email validation and optional invitation
   */
  static async create(options) {
    assertCreateOptions(options, 'Service');
    const {
      data,
      currentUser,
      sendInvitationEmails = true,
      host,
      transaction: externalTransaction,
      runtimeContext,
    } = options;
    const transaction =
      externalTransaction || (await db.sequelize.transaction());
    const ownsTransaction = !externalTransaction;
    const email = data.email;

    try {
      if (!email) {
        throw new ValidationError('iam.errors.emailRequired');
      }

      const existingUser = await db.users.findOne({
        where: { email },
        paranoid: false,
        transaction,
      });

      if (existingUser && !existingUser.deletedAt) {
        throw new ValidationError('iam.errors.userAlreadyExists');
      }

      const isPublicUserData = await this.assertPublicUserHasNoAdminPermissions(
        data,
        transaction,
      );
      const sanitizedData = isPublicUserData
        ? { ...data, custom_permissions: [] }
        : data;

      let user;

      if (existingUser?.deletedAt) {
        await existingUser.restore({ transaction });
        user = await UsersDBApi.update({
          id: existingUser.id,
          data: sanitizedData,
          currentUser,
          transaction,
          runtimeContext,
        });
      } else {
        user = await UsersDBApi.create({
          data: sanitizedData,
          currentUser,
          transaction,
          runtimeContext,
        });
      }

      await this.createProductionPresentationAccessForPublicUser({
        user,
        data: sanitizedData,
        currentUser,
        transaction,
      });
      if (ownsTransaction) await transaction.commit();

      // Send invitation email after successful commit
      if (sendInvitationEmails) {
        AuthService.sendPasswordResetEmail(email, 'invitation', host).catch(
          (error) => {
            logger.error(
              { err: error, email },
              'Failed to send user invitation email',
            );
          },
        );
      }
    } catch (error) {
      if (ownsTransaction) await transaction.rollback();
      throw error;
    }
  }

  static async update(options) {
    assertUpdateOptions(options, 'Service');
    const {
      id,
      data,
      currentUser,
      transaction: externalTransaction,
      runtimeContext,
    } = options;
    const transaction =
      externalTransaction || (await db.sequelize.transaction());
    const ownsTransaction = !externalTransaction;

    try {
      const existingUser = await UsersDBApi.findBy(
        { id },
        { transaction, runtimeContext },
      );

      if (!existingUser) {
        throw new ValidationError('UsersNotFound');
      }

      const roleId = this.normalizeRoleId(data.app_role);
      const role = roleId
        ? await db.roles.findByPk(roleId, { transaction })
        : null;
      const nextRoleName = role?.name || existingUser.app_role?.name;
      const nextUser = {
        ...existingUser,
        app_role: { name: nextRoleName },
        custom_permissions:
          data.custom_permissions || existingUser.custom_permissions,
      };

      if (AccessPolicy.isPublicUser(nextUser)) {
        await this.assertPublicUserHasNoAdminPermissions(
          {
            ...data,
            app_role: roleId || existingUser.app_role?.id,
          },
          transaction,
        );
      }

      const sanitizedData = AccessPolicy.isPublicUser(nextUser)
        ? { ...data, custom_permissions: [] }
        : data;

      const user = await UsersDBApi.update({
        id,
        data: sanitizedData,
        currentUser,
        transaction,
        runtimeContext,
      });

      if (
        Object.prototype.hasOwnProperty.call(
          data,
          'allowed_private_production_project_ids',
        )
      ) {
        await this.updateProductionPresentationAccessForPublicUser({
          user,
          data,
          currentUser,
          transaction,
        });
      }

      if (ownsTransaction) await transaction.commit();
      return user;
    } catch (error) {
      if (ownsTransaction) await transaction.rollback();
      throw error;
    }
  }

  /**
   * Remove user with self-deletion and permission checks
   */
  static async remove(options) {
    assertIdOptions(options, 'Service', 'remove');
    const { id, currentUser, transaction, runtimeContext } = options;

    if (currentUser.id === id) {
      throw new ValidationError('iam.errors.deletingHimself');
    }

    if (currentUser.app_role?.name !== config.roles.admin) {
      throw new ValidationError('errors.forbidden.message');
    }

    // Delegate to parent (factory) implementation
    return super.remove({ id, currentUser, transaction, runtimeContext });
  }
}

module.exports = UsersService;