From 69094da9974668996387978cf75990a6ad380e21 Mon Sep 17 00:00:00 2001
From: Inanc Gumus <m@inanc.io>
Date: Tue, 6 Aug 2019 01:49:48 +0300
Subject: [PATCH] refactor: log parser text writer and func types

---
 .../log-parser-exp/filterby.go                |  2 ++
 .../log-parser-exp/filters.go                 |  2 +-
 .../log-parser-exp/groupby.go                 |  2 ++
 .../log-parser-exp/main.go                    | 17 ++++++++++---
 .../log-parser-exp/report.go                  |  2 --
 .../log-parser-exp/textwriter.go              | 25 +++++++++++--------
 6 files changed, 34 insertions(+), 16 deletions(-)

diff --git a/27-functional-programming/log-parser-exp/filterby.go b/27-functional-programming/log-parser-exp/filterby.go
index 7201aa7..5e88916 100644
--- a/27-functional-programming/log-parser-exp/filterby.go
+++ b/27-functional-programming/log-parser-exp/filterby.go
@@ -1,5 +1,7 @@
 package main
 
+type filterFunc func(result) (include bool)
+
 func filterBy(results []result, filterer filterFunc) []result {
 	out := results[:0]
 
diff --git a/27-functional-programming/log-parser-exp/filters.go b/27-functional-programming/log-parser-exp/filters.go
index 68de7cb..c5032ef 100644
--- a/27-functional-programming/log-parser-exp/filters.go
+++ b/27-functional-programming/log-parser-exp/filters.go
@@ -6,7 +6,7 @@ func noopFilter(r result) bool {
 	return true
 }
 
-func not(filter filterFunc) filterFunc {
+func notUsing(filter filterFunc) filterFunc {
 	return func(r result) bool {
 		return !filter(r)
 	}
diff --git a/27-functional-programming/log-parser-exp/groupby.go b/27-functional-programming/log-parser-exp/groupby.go
index 7d9f71a..a7f069f 100644
--- a/27-functional-programming/log-parser-exp/groupby.go
+++ b/27-functional-programming/log-parser-exp/groupby.go
@@ -1,5 +1,7 @@
 package main
 
+type groupFunc func(result) (key string)
+
 func groupBy(results []result, keyer groupFunc) []result {
 	grouped := make(map[string]result, len(results))
 
diff --git a/27-functional-programming/log-parser-exp/main.go b/27-functional-programming/log-parser-exp/main.go
index 76e5642..ccf03f8 100644
--- a/27-functional-programming/log-parser-exp/main.go
+++ b/27-functional-programming/log-parser-exp/main.go
@@ -20,7 +20,7 @@ func main() {
 		to(os.Stdout).
 		retrieveFrom(textReader).
 		filterBy(orgDomainsFilter).
-		// filterBy(not(domainExtFilter("org", "io"))).
+		// filterBy(notUsing(domainExtFilter("org", "io"))).
 		// groupBy(pageGrouper).
 		groupBy(domainGrouper).
 		writeTo(textWriter).
@@ -44,6 +44,17 @@ func recoverErr() {
 }
 
 /*
-newReport -> stats.NewReport().
-Result    -> stats.Record
+newReport -> report.New().
+Result    -> report.Line
+
+notUsing = report.Not
+
+_, err := stats.Parse().
+	From(os.Stdin).
+	To(os.Stdout).
+	RetrieveFrom(stats.TextReader).
+	FilterBy(notUsing(stats.DomainExtFilter("org", "io"))).
+	GroupBy(stats.DomainGrouper).
+	WriteTo(stats.TextWriter).
+	Run()
 */
diff --git a/27-functional-programming/log-parser-exp/report.go b/27-functional-programming/log-parser-exp/report.go
index a08e3b5..52f9e9c 100644
--- a/27-functional-programming/log-parser-exp/report.go
+++ b/27-functional-programming/log-parser-exp/report.go
@@ -4,8 +4,6 @@ import "io"
 
 type (
 	retrieveFunc func(io.Reader) ([]result, error)
-	filterFunc   func(result) bool
-	groupFunc    func(result) string
 	writeFunc    func(io.Writer, []result) error
 )
 
diff --git a/27-functional-programming/log-parser-exp/textwriter.go b/27-functional-programming/log-parser-exp/textwriter.go
index d9be406..995cdba 100644
--- a/27-functional-programming/log-parser-exp/textwriter.go
+++ b/27-functional-programming/log-parser-exp/textwriter.go
@@ -8,23 +8,28 @@ import (
 
 // TODO: sort by result key interfaces section
 
-func textWriter(w io.Writer, results []result) error {
-	fmt.Fprintf(w, "%-25s %-10s %10s %10s\n",
-		"DOMAINS", "PAGES", "VISITS", "UNIQUES")
+const (
 
-	fmt.Fprintln(w, strings.Repeat("-", 58))
+	//          DOMAINS PAGES VISITS UNIQUES
+	//             ^      ^     ^    ^
+	//             |      |     |    |
+	header     = "%-25s %-10s %10s %10s\n"
+	line       = "%-25s %-10s %10d %10d\n"
+	footer     = "\n%-36s %10d %10d\n" // -> "" VISITS UNIQUES
+	dashLength = 58
+)
+
+func textWriter(w io.Writer, results []result) error {
+	fmt.Fprintf(w, header, "DOMAINS", "PAGES", "VISITS", "UNIQUES")
+	fmt.Fprintln(w, strings.Repeat("-", dashLength))
 
 	var total result
-
 	for _, r := range results {
 		total = total.add(r)
-
-		fmt.Fprintf(w, "%-25s %-10s %10d %10d\n",
-			r.domain, r.page, r.visits, r.uniques)
+		fmt.Fprintf(w, line, r.domain, r.page, r.visits, r.uniques)
 	}
 
-	fmt.Fprintf(w, "\n%-36s %10d %10d\n",
-		"", total.visits, total.uniques)
+	fmt.Fprintf(w, footer, "", total.visits, total.uniques)
 
 	return nil
 }