package task

import "testing"

func TestHappyPath(t *testing.T) {
	path := []struct {
		action Action
		want   string
	}{
		{ActionSubmit, PendingReview},
		{ActionApprove, Queued},
		{ActionDispatch, Dispatched},
		{ActionStart, Running},
		{ActionSuccess, Success},
	}
	cur := Draft
	for _, step := range path {
		next, ok := Next(cur, step.action)
		if !ok || next != step.want {
			t.Fatalf("step %s from %s: got %s ok=%v, want %s", step.action, cur, next, ok, step.want)
		}
		cur = next
	}
}

func TestFailureRetry(t *testing.T) {
	cur, ok := Next(Draft, ActionSubmit)
	if !ok {
		t.Fatal("submit failed")
	}
	cur, ok = Next(cur, ActionApprove)
	if !ok {
		t.Fatal("approve failed")
	}
	cur, ok = Next(cur, ActionDispatch)
	if !ok {
		t.Fatal("dispatch failed")
	}
	cur, ok = Next(cur, ActionStart)
	if !ok {
		t.Fatal("start failed")
	}
	cur, ok = Next(cur, ActionFail)
	if !ok || cur != Failed {
		t.Fatalf("fail: got %s ok=%v", cur, ok)
	}
	cur, ok = Next(cur, ActionRetry)
	if !ok || cur != Queued {
		t.Fatalf("retry: got %s ok=%v", cur, ok)
	}
}

func TestSuspendResume(t *testing.T) {
	cur, _ := Next(Running, ActionSuspend)
	if cur != Suspended {
		t.Fatalf("suspend: got %s", cur)
	}
	cur, ok := Next(cur, ActionResume)
	if !ok || cur != Queued {
		t.Fatalf("resume: got %s ok=%v", cur, ok)
	}
}

func TestIllegalTransitions(t *testing.T) {
	cases := []struct {
		cur    string
		action Action
	}{
		{Draft, ActionApprove},
		{PendingReview, ActionStart},
		{Queued, ActionSuccess},
		{Success, ActionRetry},
		{Cancelled, ActionResubmit},
		{Running, ActionApprove},
		{Dispatched, ActionSuspend},
	}
	for _, c := range cases {
		if _, ok := Next(c.cur, c.action); ok {
			t.Fatalf("illegal transition should fail: %s -> %s", c.cur, c.action)
		}
	}
}