api: Add go files

I know this is a huge commit, but I can't be bothered to check
this in part by part.

api/comment_approve.go

@@ -0,0 +1,68 @@
+package main
+
+import (
+	"net/http"
+)
+
+func commentApprove(commentHex string) error {
+	if commentHex == "" {
+		return errorMissingField
+	}
+
+	statement := `
+		UPDATE comments
+    SET state = 'approved'
+		WHERE commentHex = $1;
+	`
+
+	_, err := db.Exec(statement, commentHex)
+	if err != nil {
+		logger.Errorf("cannot approve comment: %v", err)
+		return errorInternal
+	}
+
+	return nil
+}
+
+func commentApproveHandler(w http.ResponseWriter, r *http.Request) {
+	type request struct {
+		Session    *string `json:"session"`
+		CommentHex *string `json:"commentHex"`
+	}
+
+	var x request
+	if err := unmarshalBody(r, &x); err != nil {
+		writeBody(w, response{"success": false, "message": err.Error()})
+		return
+	}
+
+	c, err := commenterGetBySession(*x.Session)
+	if err != nil {
+		writeBody(w, response{"success": false, "message": err.Error()})
+		return
+	}
+
+	domain, err := commentDomainGet(*x.CommentHex)
+	if err != nil {
+		writeBody(w, response{"success": false, "message": err.Error()})
+		return
+	}
+
+	isModerator, err := isDomainModerator(c.Email, domain)
+	if err != nil {
+		writeBody(w, response{"success": false, "message": err.Error()})
+		return
+	}
+
+	if !isModerator {
+		writeBody(w, response{"success": false, "message": errorNotModerator.Error()})
+		return
+	}
+
+	if err = commentApprove(*x.CommentHex); err != nil {
+		writeBody(w, response{"success": false, "message": err.Error()})
+		return
+	}
+
+	writeBody(w, response{"success": true})
+}