git.giacomolli.uk - onechat/blob - config.go

   1 package main
   2
   3 import (
   4         "bytes"
   5         "encoding/json"
   6         "errors"
   7         "fmt"
   8         "io"
   9         "os"
  10         "path/filepath"
  11 )
  12
  13 const (
  14         // configEndpointChatGPT names the ChatGPT backend with the subscription
  15         // login.
  16         configEndpointChatGPT = "chatgpt"
  17
  18         // configEndpointAPI names the OpenAI API with an API key.
  19         configEndpointAPI = "api"
  20 )
  21
  22 // Config holds the settings of config.json in the data directory.
  23 type Config struct {
  24         Endpoint  string      `json:"endpoint"`
  25         Voice     VoiceConfig `json:"voice"`
  26         Compactor ModelConfig `json:"compactor"`
  27 }
  28
  29 // ModelConfig names a model and its reasoning effort.
  30 type ModelConfig struct {
  31         Model  string `json:"model"`
  32         Effort string `json:"effort"`
  33 }
  34
  35 // loadConfig reads config.json in dir over the defaults. A missing file gives
  36 // the defaults. An unknown field is an error, so a typo does not become a
  37 // silent default.
  38 func loadConfig(dir string) (Config, error) {
  39         config := defaultConfig()
  40         data, err := os.ReadFile(filepath.Join(dir, "config.json"))
  41         if errors.Is(err, os.ErrNotExist) {
  42                 return config, nil
  43         }
  44
  45         if err != nil {
  46                 return Config{}, fmt.Errorf("read config: %w", err)
  47         }
  48
  49         decoder := json.NewDecoder(bytes.NewReader(data))
  50         decoder.DisallowUnknownFields()
  51
  52         err = decoder.Decode(&config)
  53         if err == nil && !errors.Is(decoder.Decode(&struct{}{}), io.EOF) {
  54                 err = errors.New("data after the JSON object")
  55         }
  56
  57         if err == nil {
  58                 err = config.validate()
  59         }
  60
  61         if err != nil {
  62                 return Config{}, fmt.Errorf("config.json: %w", err)
  63         }
  64
  65         return config, nil
  66 }
  67
  68 // validate makes sure that each setting has a valid value.
  69 func (c Config) validate() error {
  70         if c.Endpoint != configEndpointChatGPT && c.Endpoint != configEndpointAPI {
  71                 return fmt.Errorf("endpoint %q is not %q or %q", c.Endpoint, configEndpointChatGPT, configEndpointAPI)
  72         }
  73
  74         if c.Compactor.Model == "" || c.Compactor.Effort == "" {
  75                 return errors.New("compactor needs a model and an effort")
  76         }
  77
  78         return nil
  79 }
  80
  81 // defaultConfig returns the settings that apply when config.json does not
  82 // set them.
  83 func defaultConfig() Config {
  84         return Config{
  85                 Endpoint: configEndpointChatGPT,
  86                 Compactor: ModelConfig{
  87                         Model:  "gpt-6.1-sol",
  88                         Effort: "high",
  89                 },
  90         }
  91 }