Restructure & refactor codebase

internal/glance/widget-custom-api.go

@@ -0,0 +1,209 @@
+package glance
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"html/template"
+	"io"
+	"log/slog"
+	"net/http"
+	"time"
+
+	"github.com/tidwall/gjson"
+)
+
+var customAPIWidgetTemplate = mustParseTemplate("custom-api.html", "widget-base.html")
+
+type customAPIWidget struct {
+	widgetBase       `yaml:",inline"`
+	URL              optionalEnvField            `yaml:"url"`
+	Template         string                      `yaml:"template"`
+	Frameless        bool                        `yaml:"frameless"`
+	Headers          map[string]optionalEnvField `yaml:"headers"`
+	APIRequest       *http.Request               `yaml:"-"`
+	compiledTemplate *template.Template          `yaml:"-"`
+	CompiledHTML     template.HTML               `yaml:"-"`
+}
+
+func (widget *customAPIWidget) initialize() error {
+	widget.withTitle("Custom API").withCacheDuration(1 * time.Hour)
+
+	if widget.URL == "" {
+		return errors.New("URL is required")
+	}
+
+	if widget.Template == "" {
+		return errors.New("template is required")
+	}
+
+	compiledTemplate, err := template.New("").Funcs(customAPITemplateFuncs).Parse(widget.Template)
+
+	if err != nil {
+		return fmt.Errorf("parsing template: %w", err)
+	}
+
+	widget.compiledTemplate = compiledTemplate
+
+	req, err := http.NewRequest(http.MethodGet, widget.URL.String(), nil)
+	if err != nil {
+		return err
+	}
+
+	for key, value := range widget.Headers {
+		req.Header.Add(key, value.String())
+	}
+
+	widget.APIRequest = req
+
+	return nil
+}
+
+func (widget *customAPIWidget) update(ctx context.Context) {
+	compiledHTML, err := fetchAndParseCustomAPI(widget.APIRequest, widget.compiledTemplate)
+	if !widget.canContinueUpdateAfterHandlingErr(err) {
+		return
+	}
+
+	widget.CompiledHTML = compiledHTML
+}
+
+func (widget *customAPIWidget) Render() template.HTML {
+	return widget.renderTemplate(widget, customAPIWidgetTemplate)
+}
+
+func fetchAndParseCustomAPI(req *http.Request, tmpl *template.Template) (template.HTML, error) {
+	emptyBody := template.HTML("")
+
+	resp, err := defaultClient.Do(req)
+	if err != nil {
+		return emptyBody, err
+	}
+	defer resp.Body.Close()
+
+	bodyBytes, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return emptyBody, err
+	}
+
+	body := string(bodyBytes)
+
+	if !gjson.Valid(body) {
+		truncatedBody, isTruncated := limitStringLength(body, 100)
+		if isTruncated {
+			truncatedBody += "... <truncated>"
+		}
+
+		slog.Error("Invalid response JSON in custom API widget", "url", req.URL.String(), "body", truncatedBody)
+		return emptyBody, errors.New("invalid response JSON")
+	}
+
+	var templateBuffer bytes.Buffer
+
+	data := CustomAPITemplateData{
+		JSON:     decoratedGJSONResult{gjson.Parse(body)},
+		Response: resp,
+	}
+
+	err = tmpl.Execute(&templateBuffer, &data)
+	if err != nil {
+		return emptyBody, err
+	}
+
+	return template.HTML(templateBuffer.String()), nil
+}
+
+type decoratedGJSONResult struct {
+	gjson.Result
+}
+
+type CustomAPITemplateData struct {
+	JSON     decoratedGJSONResult
+	Response *http.Response
+}
+
+func gJsonResultArrayToDecoratedResultArray(results []gjson.Result) []decoratedGJSONResult {
+	decoratedResults := make([]decoratedGJSONResult, len(results))
+
+	for i, result := range results {
+		decoratedResults[i] = decoratedGJSONResult{result}
+	}
+
+	return decoratedResults
+}
+
+func (r *decoratedGJSONResult) Array(key string) []decoratedGJSONResult {
+	if key == "" {
+		return gJsonResultArrayToDecoratedResultArray(r.Result.Array())
+	}
+
+	return gJsonResultArrayToDecoratedResultArray(r.Get(key).Array())
+}
+
+func (r *decoratedGJSONResult) String(key string) string {
+	if key == "" {
+		return r.Result.String()
+	}
+
+	return r.Get(key).String()
+}
+
+func (r *decoratedGJSONResult) Int(key string) int64 {
+	if key == "" {
+		return r.Result.Int()
+	}
+
+	return r.Get(key).Int()
+}
+
+func (r *decoratedGJSONResult) Float(key string) float64 {
+	if key == "" {
+		return r.Result.Float()
+	}
+
+	return r.Get(key).Float()
+}
+
+func (r *decoratedGJSONResult) Bool(key string) bool {
+	if key == "" {
+		return r.Result.Bool()
+	}
+
+	return r.Get(key).Bool()
+}
+
+var customAPITemplateFuncs = func() template.FuncMap {
+	funcs := template.FuncMap{
+		"toFloat": func(a int64) float64 {
+			return float64(a)
+		},
+		"toInt": func(a float64) int64 {
+			return int64(a)
+		},
+		"mathexpr": func(left float64, op string, right float64) float64 {
+			if right == 0 {
+				return 0
+			}
+
+			switch op {
+			case "+":
+				return left + right
+			case "-":
+				return left - right
+			case "*":
+				return left * right
+			case "/":
+				return left / right
+			default:
+				return 0
+			}
+		},
+	}
+
+	for key, value := range globalTemplateFunctions {
+		funcs[key] = value
+	}
+
+	return funcs
+}()