package main

import (
	"bufio"
	"bytes"
	"fmt"
	"io"
	"strings"
	"testing"
)

func Test_Main(t *testing.T) {
	input := "\ta a a\t\tb b b\na a\t\tb b\fc c\td d\nc c\td."
	stdin = strings.NewReader(input)
	stdout = bytes.NewBuffer(nil)
	columnDelimiter = "\t"
	pageDelimiter = "\f"
	minimumInstances = 1
	if err := _main(); err != nil {
		t.Error(err)
	}
	t.Logf("input:\n%s", input)
	t.Logf("result:\n%s", stdout.(*bytes.Buffer).Bytes())
}

func TestReadPage(t *testing.T) {
	cases := map[string]struct {
		input string
		d     rune
		want  string
		err   error
	}{
		"ez": {
			input: "helloXworld",
			d:     'X',
			want:  "hello",
			err:   nil,
		},
		"eof found": {
			input: "helloX",
			d:     'X',
			want:  "hello",
			err:   nil,
		},
		"eof not found": {
			input: "hello",
			d:     'X',
			want:  "hello",
			err:   io.EOF,
		},
		"start of file": {
			input: "Xhello",
			d:     'X',
			want:  "",
			err:   nil,
		},
	}
	for name, d := range cases {
		c := d
		t.Run(name, func(t *testing.T) {
			r := bufio.NewReader(strings.NewReader(c.input))
			d := byte(c.d)
			got, err := _readPage(d, r)
			if fmt.Sprint(err) != fmt.Sprint(c.err) {
				t.Fatal(c.err, err)
			}
			if string(got) != c.want {
				t.Fatal(c.want, string(got))
			}
		})
	}
}