ollama/oweb/oweb.go

144 lines
2.9 KiB
Go

package oweb
import (
"bytes"
"cmp"
"context"
"encoding/json"
"errors"
"fmt"
"io"
"log"
"net/http"
"strings"
)
type Error struct {
Status int `json:"-"`
Code string `json:"code"`
Message string `json:"message"`
Field string `json:"field,omitempty"`
RawBody []byte `json:"-"`
}
func Missing(field string) error {
return &Error{
Status: 400,
Code: "missing",
Field: field,
Message: fmt.Sprintf("%s is required", field),
}
}
func Mistake(code, field, message string) error {
return &Error{
Status: 400,
Code: code,
Field: field,
Message: fmt.Sprintf("%s: %s", field, message),
}
}
func Fault(code, message string) error {
return &Error{
Status: 500,
Code: "fault",
Message: message,
}
}
func (e *Error) Error() string {
var b strings.Builder
b.WriteString("ollama: ")
b.WriteString(e.Code)
if e.Message != "" {
b.WriteString(": ")
b.WriteString(e.Message)
}
return b.String()
}
// Convinience errors
var (
ErrNotFound = &Error{Status: 404, Code: "not_found"}
ErrInternal = &Error{Status: 500, Code: "internal_error"}
ErrMethodNotAllowed = &Error{Status: 405, Code: "method_not_allowed"}
)
type HandlerFunc func(w http.ResponseWriter, r *http.Request) error
func Serve(h HandlerFunc, w http.ResponseWriter, r *http.Request) {
if err := h(w, r); err != nil {
// TODO: take a slog.Logger
log.Printf("error: %v", err)
var e *Error
if !errors.As(err, &e) {
e = ErrInternal
}
w.WriteHeader(cmp.Or(e.Status, 400))
if err := EncodeJSON(w, e); err != nil {
log.Printf("error encoding error: %v", err)
}
}
}
func DecodeUserJSON[T any](r io.Reader) (*T, error) {
v, err := DecodeJSON[T](r)
var e *json.SyntaxError
if errors.As(err, &e) {
return nil, &Error{Code: "invalid_json", Message: e.Error()}
}
var se *json.UnmarshalTypeError
if errors.As(err, &se) {
return nil, &Error{
Code: "invalid_json",
Message: fmt.Sprintf("%s (%q) is not a %s", se.Field, se.Value, se.Type),
}
}
return v, err
}
func DecodeJSON[T any](r io.Reader) (*T, error) {
var v *T
if err := json.NewDecoder(r).Decode(&v); err != nil {
var zero T
return &zero, err
}
return v, nil
}
func EncodeJSON(w io.Writer, v any) error {
return json.NewEncoder(w).Encode(v)
}
func Do[Res any](ctx context.Context, method, urlStr string, in any) (*Res, error) {
var body bytes.Buffer
if err := EncodeJSON(&body, in); err != nil {
return nil, err
}
req, err := http.NewRequestWithContext(ctx, method, urlStr, &body)
if err != nil {
return nil, err
}
res, err := http.DefaultClient.Do(req)
if err != nil {
return nil, err
}
defer res.Body.Close()
if res.StatusCode/100 != 2 {
var b bytes.Buffer
body := io.TeeReader(res.Body, &b)
e, err := DecodeJSON[Error](body)
if err != nil {
return nil, err
}
e.RawBody = b.Bytes()
return nil, e
}
return DecodeJSON[Res](res.Body)
}