package gonexapp

import (
	"encoding/json"
	"fmt"
	"net/http"
	"strings"
)

// AppAPIPreferences reads and writes one string ExApp preference for the requesting user.
type AppAPIPreferences struct {
	Cred   Credentials
	AppID  string
	Key    string
	Client *http.Client
	OCS    OCSClient
}

// NewAppAPIPreferences returns a preference store for appID and key using cred for auth.
func NewAppAPIPreferences(cred Credentials, appID, key string) AppAPIPreferences {
	return AppAPIPreferences{
		Cred:  cred,
		AppID: appID,
		Key:   key,
		OCS:   OCSClient{Cred: cred},
	}
}

func (p AppAPIPreferences) ocsClient() OCSClient {
	c := p.OCS
	if c.Cred.BaseURL == "" {
		c.Cred = p.Cred
	}
	if c.Client == nil {
		c.Client = p.Client
	}
	return c
}

// Get loads the configured preference key for the requesting user.
func (p AppAPIPreferences) Get() (string, error) {
	ocs := p.ocsClient()
	body, _ := json.Marshal(map[string]any{"configKeys": []string{p.Key}})
	raw, err := ocs.Call(http.MethodPost, "apps/app_api/api/v1/ex-app/preference/get-values", body)
	if err != nil {
		return "", err
	}
	return decodePreferenceValue(raw, p.Key)
}

// Set stores value for the configured preference key.
func (p AppAPIPreferences) Set(value string) error {
	ocs := p.ocsClient()
	body, _ := json.Marshal(map[string]any{
		"configKey":   p.Key,
		"configValue": value,
		"sensitive":   0,
	})
	_, err := ocs.Call(http.MethodPost, "apps/app_api/api/v1/ex-app/preference", body)
	return err
}

func decodePreferenceValue(raw []byte, key string) (string, error) {
	var parsed struct {
		OCS struct {
			Data []struct {
				ConfigKey   string `json:"configkey"`
				ConfigValue string `json:"configvalue"`
			} `json:"data"`
		} `json:"ocs"`
	}
	if err := json.Unmarshal(raw, &parsed); err != nil {
		var items []struct {
			ConfigKey   string `json:"configkey"`
			ConfigValue string `json:"configvalue"`
		}
		if err2 := json.Unmarshal(raw, &items); err2 != nil {
			return "", fmt.Errorf("preferences decode: %w", err)
		}
		for _, it := range items {
			if it.ConfigKey == key {
				return strings.TrimSpace(it.ConfigValue), nil
			}
		}
		return "", nil
	}
	for _, it := range parsed.OCS.Data {
		if it.ConfigKey == key {
			return strings.TrimSpace(it.ConfigValue), nil
		}
	}
	return "", nil
}