refactor outline api to become a response modifier

proxychain/responsemodifers/api_content.go

@@ -0,0 +1,47 @@
+package responsemodifers
+
+import (
+	"bytes"
+	"encoding/json"
+	"github.com/markusmobius/go-trafilatura"
+	"io"
+	"ladder/proxychain"
+	"ladder/proxychain/responsemodifers/api"
+)
+
+// APIContent creates an JSON representation of the article and returns it as an API response.
+func APIContent() proxychain.ResponseModification {
+
+	return func(chain *proxychain.ProxyChain) error {
+		// we set content-type twice here, in case another response modifier
+		// tries to forward over the original headers
+		chain.Context.Set("content-type", "application/json")
+		chain.Response.Header.Set("content-type", "application/json")
+
+		// extract dom contents
+		opts := trafilatura.Options{
+			IncludeImages: true,
+			IncludeLinks:  true,
+			//FavorPrecision:     true,
+			FallbackCandidates: nil, // TODO: https://github.com/markusmobius/go-trafilatura/blob/main/examples/chained/main.go
+			// implement fallbacks from	"github.com/markusmobius/go-domdistiller" and 	"github.com/go-shiori/go-readability"
+			OriginalURL: chain.Request.URL,
+		}
+
+		result, err := trafilatura.Extract(chain.Response.Body, opts)
+		if err != nil {
+			chain.Response.Body = api.CreateAPIErrReader(err)
+			return nil
+		}
+
+		res := api.ExtractResultToAPIResponse(result)
+		jsonData, err := json.MarshalIndent(res, "", "  ")
+		if err != nil {
+			return err
+		}
+
+		chain.Response.Body = io.NopCloser(bytes.NewReader(jsonData))
+		return nil
+	}
+
+}