package domain

import (
	"errors"
	"testing"
)

func TestApplyIsAtomicOnIllegalTransitionAndStaleRevision(t *testing.T) {
	r := NewRecord(QueueTicket, "ticket_1234567890123456", Queued)
	if _, err := r.Apply("k1", []byte(`{"state":"LIVE"}`), 0, Live); !errors.Is(err, ErrIllegalTransition) {
		t.Fatalf("illegal transition error = %v", err)
	}
	if r.State != Queued || r.Revision != 0 {
		t.Fatalf("illegal transition mutated record: %+v", r)
	}
	if _, err := r.Apply("k2", []byte(`{}`), 99, Proposed); !errors.Is(err, ErrStaleRevision) {
		t.Fatalf("stale revision error = %v", err)
	}
	if r.State != Queued || r.Revision != 0 {
		t.Fatalf("stale revision mutated record: %+v", r)
	}
}

func TestApplyReplaysIdenticalIdempotencyWithoutNewRevision(t *testing.T) {
	r := NewRecord(QueueTicket, "ticket_1234567890123456", Queued)
	payload := []byte(`{"state":"PROPOSED"}`)
	first, err := r.Apply("same-key-123456", payload, 0, Proposed)
	if err != nil {
		t.Fatal(err)
	}
	second, err := r.Apply("same-key-123456", payload, 0, Proposed)
	if err != nil {
		t.Fatal(err)
	}
	if first != second || r.Revision != 1 {
		t.Fatalf("replay advanced or changed result: first=%+v second=%+v record=%+v", first, second, r)
	}
}

func TestApplyRejectsIdempotencyKeyPayloadConfusion(t *testing.T) {
	r := NewRecord(QueueTicket, "ticket_1234567890123456", Queued)
	if _, err := r.Apply("same-key-123456", []byte("a"), 0, Proposed); err != nil {
		t.Fatal(err)
	}
	if _, err := r.Apply("same-key-123456", []byte("b"), 1, Accepted); !errors.Is(err, ErrConflict) {
		t.Fatalf("conflicting replay error = %v", err)
	}
	if r.State != Proposed || r.Revision != 1 {
		t.Fatalf("conflicting replay mutated record: %+v", r)
	}
}

func TestTerminalStatesCannotAdvance(t *testing.T) {
	for _, state := range []State{Completed, Cancelled, Expired, Failed} {
		r := NewRecord(QueueTicket, "ticket_1234567890123456", state)
		if _, err := r.Apply("terminal-key-123", []byte("x"), 0, Live); !errors.Is(err, ErrIllegalTransition) {
			t.Fatalf("%s transition error = %v", state, err)
		}
	}
}