package keypairs

import (
	"github.com/mitchellh/mapstructure"
	"github.com/rackspace/gophercloud"
	"github.com/rackspace/gophercloud/pagination"
)

// KeyPair is an SSH key known to the OpenStack cluster that is available to be injected into
// servers.
type KeyPair struct {
	// Name is used to refer to this keypair from other services within this region.
	Name string `mapstructure:"name"`

	// Fingerprint is a short sequence of bytes that can be used to authenticate or validate a longer
	// public key.
	Fingerprint string `mapstructure:"fingerprint"`

	// PublicKey is the public key from this pair, in OpenSSH format. "ssh-rsa AAAAB3Nz..."
	PublicKey string `mapstructure:"public_key"`

	// PrivateKey is the private key from this pair, in PEM format.
	// "-----BEGIN RSA PRIVATE KEY-----\nMIICXA..." It is only present if this keypair was just
	// returned from a Create call
	PrivateKey string `mapstructure:"private_key"`

	// UserID is the user who owns this keypair.
	UserID string `mapstructure:"user_id"`
}

// KeyPairPage stores a single, only page of KeyPair results from a List call.
type KeyPairPage struct {
	pagination.SinglePageBase
}

// IsEmpty determines whether or not a KeyPairPage is empty.
func (page KeyPairPage) IsEmpty() (bool, error) {
	ks, err := ExtractKeyPairs(page)
	return len(ks) == 0, err
}

// ExtractKeyPairs interprets a page of results as a slice of KeyPairs.
func ExtractKeyPairs(page pagination.Page) ([]KeyPair, error) {
	type pair struct {
		KeyPair KeyPair `mapstructure:"keypair"`
	}

	var resp struct {
		KeyPairs []pair `mapstructure:"keypairs"`
	}

	err := mapstructure.Decode(page.(KeyPairPage).Body, &resp)
	results := make([]KeyPair, len(resp.KeyPairs))
	for i, pair := range resp.KeyPairs {
		results[i] = pair.KeyPair
	}
	return results, err
}

type keyPairResult struct {
	gophercloud.Result
}

// Extract is a method that attempts to interpret any KeyPair resource response as a KeyPair struct.
func (r keyPairResult) Extract() (*KeyPair, error) {
	if r.Err != nil {
		return nil, r.Err
	}

	var res struct {
		KeyPair *KeyPair `json:"keypair" mapstructure:"keypair"`
	}

	err := mapstructure.Decode(r.Body, &res)
	return res.KeyPair, err
}

// CreateResult is the response from a Create operation. Call its Extract method to interpret it
// as a KeyPair.
type CreateResult struct {
	keyPairResult
}

// GetResult is the response from a Get operation. Call its Extract method to interpret it
// as a KeyPair.
type GetResult struct {
	keyPairResult
}

// DeleteResult is the response from a Delete operation. Call its Extract method to determine if
// the call succeeded or failed.
type DeleteResult struct {
	gophercloud.ErrResult
}