package main

import (
	"reflect"
	"testing"
)

func TestParsePages(t *testing.T) {
	ok := map[string]struct {
		in   string
		n    int
		want []int
	}{
		"single":      {"2", 5, []int{2}},
		"list":        {"1,3", 5, []int{1, 3}},
		"range":       {"2-4", 5, []int{2, 3, 4}},
		"mixed":       {"1,3-5", 5, []int{1, 3, 4, 5}},
		"overlap":     {"1-3,2-4", 5, []int{1, 2, 3, 4}},
		"all":         {"all", 3, []int{1, 2, 3}},
		"spaces":      {" 1 , 3 - 4 ", 5, []int{1, 3, 4}},
		"unordered":   {"4,1", 5, []int{1, 4}},
		"full bounds": {"1-5", 5, []int{1, 2, 3, 4, 5}},
	}
	for name, c := range ok {
		got, err := parsePages(c.in, c.n)
		if err != nil {
			t.Errorf("%s: unexpected error: %v", name, err)
			continue
		}
		if !reflect.DeepEqual(got, c.want) {
			t.Errorf("%s: parsePages(%q,%d) = %v, want %v", name, c.in, c.n, got, c.want)
		}
	}

	bad := map[string]struct {
		in string
		n  int
	}{
		"empty":         {"", 5},
		"zero":          {"0", 5},
		"beyond doc":    {"6", 5},
		"range beyond":  {"4-6", 5},
		"reversed":      {"4-2", 5},
		"junk":          {"x", 5},
		"trailing junk": {"1,", 5},
		"open range":    {"3-", 5},
	}
	for name, c := range bad {
		if got, err := parsePages(c.in, c.n); err == nil {
			t.Errorf("%s: parsePages(%q,%d) = %v, expected error", name, c.in, c.n, got)
		}
	}
}

func TestFormatPages(t *testing.T) {
	cases := map[string]struct {
		in   []int
		want string
	}{
		"single":    {[]int{2}, "2"},
		"run":       {[]int{1, 2, 3}, "1-3"},
		"mixed":     {[]int{1, 3, 4, 5, 9}, "1,3-5,9"},
		"unsorted":  {[]int{4, 1, 2}, "1-2,4"},
		"two apart": {[]int{1, 3}, "1,3"},
	}
	for name, c := range cases {
		if got := formatPages(c.in); got != c.want {
			t.Errorf("%s: formatPages(%v) = %q, want %q", name, c.in, got, c.want)
		}
	}
}