package main

import "testing"

// The choice this program makes silently, and got wrong.
//
// findPython took the newest interpreter on the machine, with a floor and no
// ceiling - backwards, because the newest Python is the one least likely to
// have binary wheels. On a Mac holding Python 3.14 it chose 3.14, pip found
// no numpy wheel for cp314, fell back to a source build and produced two
// screens of clang errors ending in "<arm_neon.h> is intended only for ARM
// and AArch64 targets". The operator's machine was fine; the version was not.
func TestTooNewIsRefusedRatherThanCompiled(t *testing.T) {
	if got := pythonVerdict(3, maxMinor+1, true); got != verdictTooNew {
		t.Errorf("3.%d = %q, want %q - picking it means a source build",
			maxMinor+1, got, verdictTooNew)
	}
	if got := pythonVerdict(3, maxMinor, true); got != verdictOK {
		t.Errorf("3.%d = %q, want %q - the ceiling is inclusive", maxMinor, got, verdictOK)
	}
}

// Too old and too new must stay different answers. Telling somebody holding
// Python 3.14 that no Python was found, or that theirs is too old, sends them
// to install a newer one - which is the direction that already failed.
func TestOldAndNewAreDifferentAnswers(t *testing.T) {
	old := pythonVerdict(3, minMinor-1, true)
	fresh := pythonVerdict(3, maxMinor+1, true)
	if old == fresh {
		t.Fatalf("3.%d and 3.%d both reported %q", minMinor-1, maxMinor+1, old)
	}
	if old != verdictTooOld {
		t.Errorf("3.%d = %q, want %q", minMinor-1, old, verdictTooOld)
	}
}

// Every version in the range is accepted, so the window this program claims
// to support is the one it actually uses.
func TestTheWholeSupportedRangeIsAccepted(t *testing.T) {
	for m := minMinor; m <= maxMinor; m++ {
		if got := pythonVerdict(3, m, true); got != verdictOK {
			t.Errorf("3.%d = %q, want %q", m, got, verdictOK)
		}
	}
	if minMinor > maxMinor {
		t.Fatal("the supported range is empty; nothing would ever be chosen")
	}
}

// A major version nobody has tested against is not something to guess at, and
// an unreadable version string is not a working interpreter.
func TestUnknownVersionsAreNotAccepted(t *testing.T) {
	for _, c := range []struct {
		name         string
		major, minor int
		parsed       bool
	}{
		{"python 4", 4, 0, true},
		{"python 2", 2, 7, true},
		{"unparseable", 0, 0, false},
	} {
		if got := pythonVerdict(c.major, c.minor, c.parsed); got == verdictOK {
			t.Errorf("%s was accepted", c.name)
		}
	}
}