package bot_test

import (
	"strings"
	"testing"

	"sneak.berlin/go/simplexcalc/internal/bot"
	"sneak.berlin/go/simplexcalc/internal/calc"
)

// TestReply: a result is sent bare, and every way of failing gets its
// own short explanation rather than silence.
func TestReply(t *testing.T) {
	t.Parallel()

	for in, want := range map[string]string{
		"2 + 2":   "4",
		"5 * 5/2": "12.5",
		"2^10":    "1024",
		"7 % 3":   "1",
		"2^1200":  "1.7218479456385751e+361",
	} {
		if got := bot.Reply(in); got != want {
			t.Errorf("Reply(%q) = %q, want %q", in, got, want)
		}
	}

	for in, want := range map[string]string{
		"hello":    "I only understand arithmetic",
		"1 / 0":    "I cannot divide by zero.",
		"1e1300":   "That needs a number too large or too small for me.",
		"1e-1300":  "That needs a number too large or too small for me.",
		"(-8)^0.5": "A negative number to a fractional power has no real",
		strings.Repeat("1+", calc.MaxInputLength) + "1": "That is too long for me",
	} {
		if got := bot.Reply(in); !strings.HasPrefix(got, want) {
			t.Errorf("Reply(%q) = %q, want it to start %q", in, got, want)
		}
	}
}