Add data model doc and sheets explorer tool

tools/sheets/main.go

@@ -0,0 +1,74 @@
+// Command sheets explores a google sheet via the service account: tabs, sizes, and header rows.
+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"log"
+	"path/filepath"
+	"strings"
+
+	"google.golang.org/api/option"
+	"google.golang.org/api/sheets/v4"
+)
+
+func keyFile() string {
+	matches, err := filepath.Glob("creds/*.json")
+	if err != nil || len(matches) == 0 {
+		log.Fatal("[ERROR] no service account key found in creds/")
+	}
+	return matches[0]
+}
+
+func main() {
+	sheet := flag.String("sheet", "", "spreadsheet id")
+	tab := flag.String("tab", "", "print rows of this tab instead of the overview")
+	rows := flag.Int("rows", 0, "with -tab, print only n rows")
+	from := flag.Int("from", 1, "with -tab and -rows, first row to print")
+	flag.Parse()
+	if *sheet == "" {
+		log.Fatal("[ERROR] -sheet <spreadsheet id> is required")
+	}
+	svc, err := sheets.NewService(context.Background(),
+		option.WithCredentialsFile(keyFile()),
+		option.WithScopes(sheets.SpreadsheetsReadonlyScope))
+	if err != nil {
+		log.Fatalf("[ERROR] create sheets client: %v", err)
+	}
+	if *tab != "" {
+		rng := quoteTab(*tab)
+		if *rows > 0 {
+			rng = fmt.Sprintf("%s!%d:%d", quoteTab(*tab), *from, *from+*rows-1)
+		}
+		resp, err := svc.Spreadsheets.Values.Get(*sheet, rng).Do()
+		if err != nil {
+			log.Fatalf("[ERROR] read tab %s: %v", *tab, err)
+		}
+		for _, row := range resp.Values {
+			fmt.Println(row)
+		}
+		return
+	}
+	ss, err := svc.Spreadsheets.Get(*sheet).Do()
+	if err != nil {
+		log.Fatalf("[ERROR] get spreadsheet: %v", err)
+	}
+	fmt.Println("title:", ss.Properties.Title)
+	for _, s := range ss.Sheets {
+		p := s.Properties
+		fmt.Printf("\ntab %q: %d rows x %d cols\n", p.Title, p.GridProperties.RowCount, p.GridProperties.ColumnCount)
+		resp, err := svc.Spreadsheets.Values.Get(*sheet, quoteTab(p.Title)+"!1:1").Do()
+		if err != nil {
+			log.Printf("[ERROR] read header of %s: %v", p.Title, err)
+			continue
+		}
+		if len(resp.Values) > 0 {
+			fmt.Printf("  header: %v\n", resp.Values[0])
+		}
+	}
+}
+
+func quoteTab(title string) string {
+	return "'" + strings.ReplaceAll(title, "'", "''") + "'"
+}