package aws

import (
	"fmt"
	"log"

	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/aws/awserr"
	"github.com/aws/aws-sdk-go/service/iam"

	"github.com/hashicorp/terraform/helper/schema"
)

func resourceAwsIamUser() *schema.Resource {
	return &schema.Resource{
		Create: resourceAwsIamUserCreate,
		Read:   resourceAwsIamUserRead,
		Update: resourceAwsIamUserUpdate,
		Delete: resourceAwsIamUserDelete,
		Importer: &schema.ResourceImporter{
			State: schema.ImportStatePassthrough,
		},

		Schema: map[string]*schema.Schema{
			"arn": &schema.Schema{
				Type:     schema.TypeString,
				Computed: true,
			},
			/*
				The UniqueID could be used as the Id(), but none of the API
				calls allow specifying a user by the UniqueID: they require the
				name. The only way to locate a user by UniqueID is to list them
				all and that would make this provider unnecessarilly complex
				and inefficient. Still, there are other reasons one might want
				the UniqueID, so we can make it available.
			*/
			"unique_id": &schema.Schema{
				Type:     schema.TypeString,
				Computed: true,
			},
			"name": &schema.Schema{
				Type:     schema.TypeString,
				Required: true,
			},
			"path": &schema.Schema{
				Type:     schema.TypeString,
				Optional: true,
				Default:  "/",
				ForceNew: true,
			},
		},
	}
}

func resourceAwsIamUserCreate(d *schema.ResourceData, meta interface{}) error {
	iamconn := meta.(*AWSClient).iamconn
	name := d.Get("name").(string)
	path := d.Get("path").(string)

	request := &iam.CreateUserInput{
		Path:     aws.String(path),
		UserName: aws.String(name),
	}

	log.Println("[DEBUG] Create IAM User request:", request)
	createResp, err := iamconn.CreateUser(request)
	if err != nil {
		return fmt.Errorf("Error creating IAM User %s: %s", name, err)
	}
	d.SetId(*createResp.User.UserName)
	return resourceAwsIamUserReadResult(d, createResp.User)
}

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

	request := &iam.GetUserInput{
		UserName: aws.String(d.Id()),
	}

	getResp, err := iamconn.GetUser(request)
	if err != nil {
		if iamerr, ok := err.(awserr.Error); ok && iamerr.Code() == "NoSuchEntity" { // XXX test me
			log.Printf("[WARN] No IAM user by name (%s) found", d.Id())
			d.SetId("")
			return nil
		}
		return fmt.Errorf("Error reading IAM User %s: %s", d.Id(), err)
	}
	return resourceAwsIamUserReadResult(d, getResp.User)
}

func resourceAwsIamUserReadResult(d *schema.ResourceData, user *iam.User) error {
	if err := d.Set("name", user.UserName); err != nil {
		return err
	}
	if err := d.Set("arn", user.Arn); err != nil {
		return err
	}
	if err := d.Set("path", user.Path); err != nil {
		return err
	}
	if err := d.Set("unique_id", user.UserId); err != nil {
		return err
	}
	return nil
}

func resourceAwsIamUserUpdate(d *schema.ResourceData, meta interface{}) error {
	if d.HasChange("name") || d.HasChange("path") {
		iamconn := meta.(*AWSClient).iamconn
		on, nn := d.GetChange("name")
		_, np := d.GetChange("path")

		request := &iam.UpdateUserInput{
			UserName:    aws.String(on.(string)),
			NewUserName: aws.String(nn.(string)),
			NewPath:     aws.String(np.(string)),
		}

		log.Println("[DEBUG] Update IAM User request:", request)
		_, err := iamconn.UpdateUser(request)
		if err != nil {
			if iamerr, ok := err.(awserr.Error); ok && iamerr.Code() == "NoSuchEntity" {
				log.Printf("[WARN] No IAM user by name (%s) found", d.Id())
				d.SetId("")
				return nil
			}
			return fmt.Errorf("Error updating IAM User %s: %s", d.Id(), err)
		}
		return resourceAwsIamUserRead(d, meta)
	}
	return nil
}
func resourceAwsIamUserDelete(d *schema.ResourceData, meta interface{}) error {
	iamconn := meta.(*AWSClient).iamconn

	// IAM Users must be removed from all groups before they can be deleted
	var groups []string
	var marker *string
	truncated := aws.Bool(true)

	for *truncated == true {
		listOpts := iam.ListGroupsForUserInput{
			UserName: aws.String(d.Id()),
		}

		if marker != nil {
			listOpts.Marker = marker
		}

		r, err := iamconn.ListGroupsForUser(&listOpts)
		if err != nil {
			return err
		}

		for _, g := range r.Groups {
			groups = append(groups, *g.GroupName)
		}

		// if there's a marker present, we need to save it for pagination
		if r.Marker != nil {
			*marker = *r.Marker
		}
		*truncated = *r.IsTruncated
	}

	for _, g := range groups {
		// use iam group membership func to remove user from all groups
		log.Printf("[DEBUG] Removing IAM User %s from IAM Group %s", d.Id(), g)
		if err := removeUsersFromGroup(iamconn, []*string{aws.String(d.Id())}, g); err != nil {
			return err
		}
	}

	request := &iam.DeleteUserInput{
		UserName: aws.String(d.Id()),
	}

	log.Println("[DEBUG] Delete IAM User request:", request)
	if _, err := iamconn.DeleteUser(request); err != nil {
		return fmt.Errorf("Error deleting IAM User %s: %s", d.Id(), err)
	}
	return nil
}