'use strict';
const IAM = require('aws-sdk/clients/iam'),
  logger = require('./logger');

module.exports.listRoles = function ({cfg}) {
  if (!cfg.taskDefinitionTemplate) throw new Error('ExitGracefully');
  const iam = new IAM({ region: cfg.region });
  return iam.listRoles().promise()
    .then((data) => {
      if (cfg.taskDefinitionTemplate && cfg.taskDefinitionTemplate.executionRole) {
        const executionRoles = data.Roles.filter((role) => { return role.RoleName === cfg.taskDefinitionTemplate.executionRole; });
        if (executionRoles.length !== 1) throw new Error(`Execution role ${cfg.taskDefinitionTemplate.executionRole} does not exist.`);
        cfg.executionRoleArn = executionRoles[0].Arn;
      }
      return {cfg, data};
    });
};

module.exports.ensureTaskRoleExists = function ({cfg, data}) {
  if (!cfg.taskRole) return {cfg};
  const iam = new IAM({ region: cfg.region });
  if (cfg.taskRole && cfg.taskRole.roleArn) {
    logger.action(`Checking if task role '${cfg.taskRole.roleArn}' already exists...`);
    const existingRoles = data.Roles.filter((role) => { return role.Arn === cfg.taskRole.roleArn; });
    if (existingRoles.length === 1) {
      return new Promise((resolve) => {
        logger.result(`${existingRoles[0].Arn}`);
        cfg.taskRoleArn = existingRoles[0].Arn;
        return resolve({ cfg, taskRole: existingRoles[0] });
      });
    }
    return new Promise((resolve, reject) => { return reject(new Error(`Role ${cfg.taskRole.roleArn} does not exist.`)); });
  } else {
    const taskRoleName = `${cfg.safePkgName}-ecs-task-role`;
    logger.action(`Checking if task role ${taskRoleName} already exists...`);
    const existingRoles = data.Roles.filter((role) => { return role.RoleName === taskRoleName; });
    if (existingRoles.length === 1) {
      return new Promise((resolve) => {
        logger.result(`${existingRoles[0].Arn}`);
        cfg.taskRoleArn = existingRoles[0].Arn;
        return resolve({ cfg, taskRole: existingRoles[0] });
      });
    }
    return iam.createRole({
      AssumeRolePolicyDocument: JSON.stringify({
        'Version': '2012-10-17',
        'Statement': [
          {
            'Sid': '',
            'Effect': 'Allow',
            'Principal': {
              'Service': 'ecs-tasks.amazonaws.com'
            },
            'Action': 'sts:AssumeRole'
          }
        ]
      }),
      RoleName: taskRoleName,
      Description: `Task role for ${cfg.fullName} ECS task`
    }).promise()
      .then((data) => {
        cfg.taskRoleArn = data.Role.Arn;
        logger.result(`created ${cfg.taskRoleArn}`);
        return { cfg, taskRole: data.Role };
      });
  }
};

module.exports.ensureTaskRolePolicyIsUpToDate = function ({cfg, taskRole}) {
  if (!taskRole || (cfg.taskRole && cfg.taskRole.roleArn)) return {cfg};
  const iam = new IAM({ region: cfg.region });
  logger.action(`Ensuring task role policy is up to date...`);
  return iam.putRolePolicy({
    PolicyDocument: JSON.stringify(cfg.taskRole.policyDocument),
    PolicyName: 'ecs-task-role-policy',
    RoleName: taskRole.RoleName
  }).promise()
    .then(() => {
      logger.result('Done');
      return {cfg};
    });
};