package userpass

import (
	"fmt"
	"strings"
	"time"

	"github.com/hashicorp/vault/logical"
	"github.com/hashicorp/vault/logical/framework"
	"golang.org/x/crypto/bcrypt"
)

func pathUsers(b *backend) *framework.Path {
	return &framework.Path{
		Pattern: "users/" + framework.GenericNameRegex("name"),
		Fields: map[string]*framework.FieldSchema{
			"name": &framework.FieldSchema{
				Type:        framework.TypeString,
				Description: "Username for this user.",
			},

			"password": &framework.FieldSchema{
				Type:        framework.TypeString,
				Description: "Password for this user.",
			},

			"policies": &framework.FieldSchema{
				Type:        framework.TypeString,
				Description: "Comma-separated list of policies",
			},
			"ttl": &framework.FieldSchema{
				Type:        framework.TypeString,
				Default:     "",
				Description: "The lease duration which decides login expiration",
			},
			"max_ttl": &framework.FieldSchema{
				Type:        framework.TypeString,
				Default:     "",
				Description: "Maximum duration after which login should expire",
			},
		},

		Callbacks: map[logical.Operation]framework.OperationFunc{
			logical.DeleteOperation: b.pathUserDelete,
			logical.ReadOperation:   b.pathUserRead,
			logical.WriteOperation:  b.pathUserWrite,
		},

		HelpSynopsis:    pathUserHelpSyn,
		HelpDescription: pathUserHelpDesc,
	}
}

func (b *backend) User(s logical.Storage, n string) (*UserEntry, error) {
	entry, err := s.Get("user/" + strings.ToLower(n))
	if err != nil {
		return nil, err
	}
	if entry == nil {
		return nil, nil
	}

	var result UserEntry
	if err := entry.DecodeJSON(&result); err != nil {
		return nil, err
	}

	return &result, nil
}

func (b *backend) pathUserDelete(
	req *logical.Request, d *framework.FieldData) (*logical.Response, error) {
	err := req.Storage.Delete("user/" + strings.ToLower(d.Get("name").(string)))
	if err != nil {
		return nil, err
	}

	return nil, nil
}

func (b *backend) pathUserRead(
	req *logical.Request, d *framework.FieldData) (*logical.Response, error) {
	user, err := b.User(req.Storage, strings.ToLower(d.Get("name").(string)))
	if err != nil {
		return nil, err
	}
	if user == nil {
		return nil, nil
	}

	return &logical.Response{
		Data: map[string]interface{}{
			"policies": strings.Join(user.Policies, ","),
		},
	}, nil
}

func (b *backend) pathUserWrite(
	req *logical.Request, d *framework.FieldData) (*logical.Response, error) {
	name := strings.ToLower(d.Get("name").(string))
	password := d.Get("password").(string)
	policies := strings.Split(d.Get("policies").(string), ",")
	for i, p := range policies {
		policies[i] = strings.TrimSpace(p)
	}

	// Generate a hash of the password
	hash, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
	if err != nil {
		return nil, err
	}

	ttlStr := d.Get("ttl").(string)
	maxTTLStr := d.Get("max_ttl").(string)
	ttl, maxTTL, err := b.SanitizeTTL(ttlStr, maxTTLStr)
	if err != nil {
		return logical.ErrorResponse(fmt.Sprintf("err: %s", err)), nil
	}

	// Store it
	entry, err := logical.StorageEntryJSON("user/"+name, &UserEntry{
		PasswordHash: hash,
		Policies:     policies,
		TTL:          ttl,
		MaxTTL:       maxTTL,
	})
	if err != nil {
		return nil, err
	}
	if err := req.Storage.Put(entry); err != nil {
		return nil, err
	}

	return nil, nil
}

type UserEntry struct {
	// Password is deprecated in Vault 0.2 in favor of
	// PasswordHash, but is retained for backwards compatibilty.
	Password string

	// PasswordHash is a bcrypt hash of the password. This is
	// used instead of the actual password in Vault 0.2+.
	PasswordHash []byte

	Policies []string

	// Duration after which the user will be revoked unless renewed
	TTL time.Duration

	// Maximum duration for which user can be valid
	MaxTTL time.Duration
}

const pathUserHelpSyn = `
Manage users allowed to authenticate.
`

const pathUserHelpDesc = `
This endpoint allows you to create, read, update, and delete users
that are allowed to authenticate.

Deleting a user will not revoke auth for prior authenticated users
with that name. To do this, do a revoke on "login/<username>" for
the username you want revoked. If you don't need to revoke login immediately,
then the next renew will cause the lease to expire.
`