package processing

import (
	"context"
	"errors"
	"testing"

	"github.com/google/uuid"
)

func TestChunkUUIDs(t *testing.T) {
	ids := make([]uuid.UUID, 12)
	for i := range ids {
		ids[i] = uuid.New()
	}
	chunks := chunkUUIDs(ids, 5)
	if len(chunks) != 3 {
		t.Fatalf("chunks=%d want 3", len(chunks))
	}
	if len(chunks[0]) != 5 || len(chunks[1]) != 5 || len(chunks[2]) != 2 {
		t.Fatalf("sizes=%d,%d,%d", len(chunks[0]), len(chunks[1]), len(chunks[2]))
	}
	if chunks[0][0] != ids[0] || chunks[2][1] != ids[11] {
		t.Fatal("chunk order must preserve input order")
	}
	if chunkUUIDs(nil, 5) != nil {
		t.Fatal("nil/empty input must return nil")
	}
	one := chunkUUIDs(ids[:3], 0)
	if len(one) != 1 || len(one[0]) != 3 {
		t.Fatalf("size<=0 must keep whole slice, got %v", one)
	}
}

func TestChunkUUIDs_jobCapBoundaries(t *testing.T) {
	ids := make([]uuid.UUID, maxJobProducts+1)
	chunks := chunkUUIDs(ids, maxJobProducts)
	if len(chunks) != 2 {
		t.Fatalf("chunks=%d want 2", len(chunks))
	}
	if len(chunks[0]) != maxJobProducts || len(chunks[1]) != 1 {
		t.Fatalf("sizes=%d,%d", len(chunks[0]), len(chunks[1]))
	}
	exact := chunkUUIDs(ids[:maxJobProducts], maxJobProducts)
	if len(exact) != 1 || len(exact[0]) != maxJobProducts {
		t.Fatalf("exact cap must be one chunk, got %d chunks", len(exact))
	}
}

func TestStartJobRejectsOverMaxStartProducts(t *testing.T) {
	p := &Pipeline{}
	ids := make([]uuid.UUID, MaxStartProducts+1)
	_, err := p.StartJob(context.Background(), uuid.New(), uuid.New(), ids, "full")
	if !errors.Is(err, ErrTooManyProducts) {
		t.Fatalf("err=%v want ErrTooManyProducts", err)
	}
}

func TestAssertProcessingGatesNilBilling(t *testing.T) {
	p := &Pipeline{}
	if err := p.assertProcessingGates(context.Background(), uuid.New(), "enhance", 3); err != nil {
		t.Fatalf("nil billing must no-op: %v", err)
	}
}

func TestStartJobRejectsEmpty(t *testing.T) {
	p := &Pipeline{}
	_, err := p.StartJob(context.Background(), uuid.New(), uuid.New(), nil, "full")
	if !errors.Is(err, ErrRawIDsRequired) {
		t.Fatalf("err=%v want ErrRawIDsRequired", err)
	}
}