package aws

import (
	"fmt"
	"log"
	"time"

	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/service/autoscaling"
	"github.com/hashicorp/terraform/helper/schema"
)

const awsAutoscalingScheduleTimeLayout = "2006-01-02T15:04:05Z"

func resourceAwsAutoscalingSchedule() *schema.Resource {
	return &schema.Resource{
		Create: resourceAwsAutoscalingScheduleCreate,
		Read:   resourceAwsAutoscalingScheduleRead,
		Update: resourceAwsAutoscalingScheduleCreate,
		Delete: resourceAwsAutoscalingScheduleDelete,

		Schema: map[string]*schema.Schema{
			"arn": &schema.Schema{
				Type:     schema.TypeString,
				Computed: true,
			},
			"scheduled_action_name": &schema.Schema{
				Type:     schema.TypeString,
				Required: true,
				ForceNew: true,
			},
			"autoscaling_group_name": &schema.Schema{
				Type:     schema.TypeString,
				Required: true,
				ForceNew: true,
			},
			"start_time": &schema.Schema{
				Type:         schema.TypeString,
				Optional:     true,
				Computed:     true,
				ValidateFunc: validateASGScheduleTimestamp,
			},
			"end_time": &schema.Schema{
				Type:         schema.TypeString,
				Optional:     true,
				Computed:     true,
				ValidateFunc: validateASGScheduleTimestamp,
			},
			"recurrence": &schema.Schema{
				Type:     schema.TypeString,
				Optional: true,
				Computed: true,
			},
			"min_size": &schema.Schema{
				Type:     schema.TypeInt,
				Optional: true,
				Computed: true,
			},
			"max_size": &schema.Schema{
				Type:     schema.TypeInt,
				Optional: true,
				Computed: true,
			},
			"desired_capacity": &schema.Schema{
				Type:     schema.TypeInt,
				Optional: true,
				Computed: true,
			},
		},
	}
}

func resourceAwsAutoscalingScheduleCreate(d *schema.ResourceData, meta interface{}) error {
	autoscalingconn := meta.(*AWSClient).autoscalingconn
	params := &autoscaling.PutScheduledUpdateGroupActionInput{
		AutoScalingGroupName: aws.String(d.Get("autoscaling_group_name").(string)),
		ScheduledActionName:  aws.String(d.Get("scheduled_action_name").(string)),
	}

	if attr, ok := d.GetOk("start_time"); ok {
		t, err := time.Parse(awsAutoscalingScheduleTimeLayout, attr.(string))
		if err != nil {
			return fmt.Errorf("Error Parsing AWS Autoscaling Group Schedule Start Time: %s", err.Error())
		}
		params.StartTime = aws.Time(t)
	}

	if attr, ok := d.GetOk("end_time"); ok {
		t, err := time.Parse(awsAutoscalingScheduleTimeLayout, attr.(string))
		if err != nil {
			return fmt.Errorf("Error Parsing AWS Autoscaling Group Schedule End Time: %s", err.Error())
		}
		params.EndTime = aws.Time(t)
	}

	if attr, ok := d.GetOk("recurrance"); ok {
		params.Recurrence = aws.String(attr.(string))
	}

	if attr, ok := d.GetOk("min_size"); ok {
		params.MinSize = aws.Int64(int64(attr.(int)))
	}

	if attr, ok := d.GetOk("max_size"); ok {
		params.MaxSize = aws.Int64(int64(attr.(int)))
	}

	if attr, ok := d.GetOk("desired_capacity"); ok {
		params.DesiredCapacity = aws.Int64(int64(attr.(int)))
	}

	log.Printf("[INFO] Creating Autoscaling Scheduled Action: %s", d.Get("scheduled_action_name").(string))
	_, err := autoscalingconn.PutScheduledUpdateGroupAction(params)
	if err != nil {
		return fmt.Errorf("Error Creating Autoscaling Scheduled Action: %s", err.Error())
	}

	d.SetId(d.Get("scheduled_action_name").(string))

	return resourceAwsAutoscalingScheduleRead(d, meta)
}

func resourceAwsAutoscalingScheduleRead(d *schema.ResourceData, meta interface{}) error {
	sa, err := resourceAwsASGScheduledActionRetrieve(d, meta)
	if err != nil {
		return err
	}

	d.Set("autoscaling_group_name", sa.AutoScalingGroupName)
	d.Set("arn", sa.ScheduledActionARN)
	d.Set("desired_capacity", sa.DesiredCapacity)
	d.Set("min_size", sa.MinSize)
	d.Set("max_size", sa.MaxSize)
	d.Set("recurrance", sa.Recurrence)
	d.Set("start_time", sa.StartTime.Format(awsAutoscalingScheduleTimeLayout))
	d.Set("end_time", sa.EndTime.Format(awsAutoscalingScheduleTimeLayout))

	return nil
}

func resourceAwsAutoscalingScheduleDelete(d *schema.ResourceData, meta interface{}) error {
	autoscalingconn := meta.(*AWSClient).autoscalingconn

	params := &autoscaling.DeleteScheduledActionInput{
		AutoScalingGroupName: aws.String(d.Get("autoscaling_group_name").(string)),
		ScheduledActionName:  aws.String(d.Id()),
	}

	log.Printf("[INFO] Deleting Autoscaling Scheduled Action: %s", d.Id())
	_, err := autoscalingconn.DeleteScheduledAction(params)
	if err != nil {
		return fmt.Errorf("Error deleting Autoscaling Scheduled Action: %s", err.Error())
	}

	return nil
}

func resourceAwsASGScheduledActionRetrieve(d *schema.ResourceData, meta interface{}) (*autoscaling.ScheduledUpdateGroupAction, error) {
	autoscalingconn := meta.(*AWSClient).autoscalingconn

	params := &autoscaling.DescribeScheduledActionsInput{
		AutoScalingGroupName: aws.String(d.Get("autoscaling_group_name").(string)),
		ScheduledActionNames: []*string{aws.String(d.Id())},
	}

	log.Printf("[INFO] Describing Autoscaling Scheduled Action: %+v", params)
	actions, err := autoscalingconn.DescribeScheduledActions(params)
	if err != nil {
		return nil, fmt.Errorf("Error retrieving Autoscaling Scheduled Actions: %s", err)
	}

	if len(actions.ScheduledUpdateGroupActions) != 1 ||
		*actions.ScheduledUpdateGroupActions[0].ScheduledActionName != d.Id() {
		return nil, fmt.Errorf("Unable to find Autoscaling Scheduled Action: %#v", actions.ScheduledUpdateGroupActions)
	}

	return actions.ScheduledUpdateGroupActions[0], nil
}

func validateASGScheduleTimestamp(v interface{}, k string) (ws []string, errors []error) {
	value := v.(string)
	_, err := time.Parse(awsAutoscalingScheduleTimeLayout, value)
	if err != nil {
		errors = append(errors, fmt.Errorf(
			"%q cannot be parsed as iso8601 Timestamp Format", value))
	}

	return
}