refactor: logparser

interfaces/05-log-parser/oop/report.go

@@ -7,34 +7,57 @@
 
 package main
 
-type notifier interface {
-	notify(func(r result))
-}
+import (
+	"errors"
+	"os"
+	"strings"
+)
+
+type resultFn func(result)
 
 type parser interface {
-	parse() error
-	notifier
-}
-
-type iterator interface {
-	each(func(result))
+	parse(resultFn) error
 }
 
 type analyser interface {
 	analyse(result)
-	iterator
+}
+
+type iterator interface {
+	each(resultFn)
 }
 
 type summarizer interface {
 	summarize(iterator) error
 }
 
-func report(a analyser, p parser, s summarizer) error {
-	p.notify(a.analyse)
-
-	if err := p.parse(); err != nil {
+func report(p parser, a analyser, s summarizer) error {
+	if err := p.parse(a.analyse); err != nil {
 		return err
 	}
 
-	return s.summarize(a)
+	it, ok := a.(iterator)
+	if !ok {
+		return errors.New("cannot iterate on analyser")
+	}
+
+	return s.summarize(it)
+}
+
+// reportFromFile generates a default report
+func reportFromFile(path string) (err error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return err
+	}
+
+	var p parser
+	switch {
+	case strings.HasSuffix(path, ".txt"):
+		p = newTextParser(f)
+	case strings.HasSuffix(path, ".json"):
+		p = newJSONParser(f)
+	}
+
+	return report(p, newAnalysis(), newTextSummary())
 }