package saltyim

import (
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"os"

	"go.mills.io/salty"
)

// RegisterRequest is the request used by clients to register to a broker
type RegisterRequest struct {
	Hash string
	Key  string
}

// NewRegisterRequest reads the signed request body from a client, verifies its signature
// and returns the resulting `RegisterRequest` and key used to sign the request on success
// otherwise an empty object and en error on failure.
func NewRegisterRequest(r io.Reader) (req RegisterRequest, signer string, err error) {
	body, err := io.ReadAll(r)
	if err != nil {
		return
	}
	out, key, err := salty.Verify(body)
	if err != nil {
		return
	}
	signer = key.ID().String()
	err = json.Unmarshal(out, &req)
	return
}

// SendRequest is the request used by clients to send messages via a broker
type SendRequest struct {
	Endpoint     string
	Message      string
	Capabilities Capabilities
}

// NewSendRequest reads the signed request body from a client, verifies its signature
// and returns the resulting `SendRequest` and key used to sign the request on success
// otherwise an empty object and en error on failure.
func NewSendRequest(r io.Reader) (req SendRequest, signer string, err error) {
	body, err := io.ReadAll(r)
	if err != nil {
		return
	}
	out, key, err := salty.Verify(body)
	if err != nil {
		return
	}
	signer = key.ID().String()
	err = json.Unmarshal(out, &req)
	return
}

// AvatarRequest is the request used by clients to update avatars stored on a broker's avatar service.
type AvatarRequest struct {
	Addr    Addr
	Content []byte
}

// NewAvatarRequest reads the signed request body from a client, verifies its signature
// and returns the resulting `AvatarRequest` and key used to sign the request on success
// otherwise an empty object and en error on failure.
func NewAvatarRequest(r io.Reader) (req AvatarRequest, signer string, err error) {
	body, err := io.ReadAll(r)
	if err != nil {
		return
	}
	out, key, err := salty.Verify(body)
	if err != nil {
		return
	}
	signer = key.ID().String()
	err = json.Unmarshal(out, &req)
	return
}

// Blob defines the type, filename and whether or not a blob is publicly accessible or not.
// A Blob also holds zero or more properties as a map of key/value pairs of string interpreted
// by the client.
type Blob struct {
	r io.ReadSeekCloser

	Type       string
	Public     bool
	Filename   string
	Properties map[string]string
}

// Close closes the blob and the underlying io.ReadSeekCloser
func (b *Blob) Close() error { return b.r.Close() }

// Read reads data from the blob from the underlying io.ReadSeekCloser
func (b *Blob) Read(p []byte) (n int, err error) { return b.r.Read(p) }

// SetHeaders sets HTTP headers on the net/http.Request object based on the blob's type, filename
// and various other properties (if any).
func (b *Blob) SetHeaders(r *http.Request) {
	// TODO: Implement this...
}

// OpenBlob opens a blob at the given path and returns a Blob object
func OpenBlob(fn string) (*Blob, error) {
	f, err := os.Open(fn)
	if err != nil {
		return nil, fmt.Errorf("error opening blob %s: %w", fn, err)
	}

	return &Blob{r: f}, nil
}

// BlobRequest is the request used by clients to update blob metadata for blobs stored on a broker.
type BlobRequest struct {
	Blob
}

// NewBlobRequest reads the signed request body from a client, verifies its signature
// and returns the resulting `BlobRequest` and key used to sign the request on success
// otherwise an empty object and an error on failure.
func NewBlobRequest(r io.Reader) (req BlobRequest, signer string, err error) {
	body, err := io.ReadAll(r)
	if err != nil {
		return
	}
	out, key, err := salty.Verify(body)
	if err != nil {
		return
	}
	signer = key.ID().String()
	err = json.Unmarshal(out, &req)
	return
}

// NewRawRequest reads the signed request body from a client, verifies its signature
// and returns the resulting `[]byte` slice and key used to sign the request on success
// otherwise an empty object and an error on failure.
func NewRawRequest(r io.Reader) (out []byte, signer string, err error) {
	body, err := io.ReadAll(r)
	if err != nil {
		return
	}
	out, key, err := salty.Verify(body)
	if err != nil {
		return
	}
	signer = key.ID().String()
	return
}