package ai

import (
	"context"
	"errors"
	"strings"
	"testing"
)

func TestReviewPromptIncludesSessionAndHistory(t *testing.T) {
	fb := &fakeBackend{out: `{"recap":"r","carry_forward":"c"}`}
	if _, err := NewService(fb).Review(context.Background(), "FINISHED-BLOCK", "HISTORY-BLOCK"); err != nil {
		t.Fatalf("review: %v", err)
	}
	if !strings.Contains(fb.gotPrompt, "FINISHED-BLOCK") {
		t.Fatalf("prompt missing finished session: %s", fb.gotPrompt)
	}
	if !strings.Contains(fb.gotPrompt, "HISTORY-BLOCK") || !strings.Contains(fb.gotPrompt, "Recent sessions") {
		t.Fatalf("prompt missing history block: %s", fb.gotPrompt)
	}
}

func TestReviewPromptOmitsEmptyHistory(t *testing.T) {
	fb := &fakeBackend{out: `{"recap":"r","carry_forward":"c"}`}
	if _, err := NewService(fb).Review(context.Background(), "FINISHED-BLOCK", ""); err != nil {
		t.Fatalf("review: %v", err)
	}
	if strings.Contains(fb.gotPrompt, "Recent sessions") {
		t.Fatalf("empty history must not add a history header: %s", fb.gotPrompt)
	}
}

func TestReviewServiceParsesReflection(t *testing.T) {
	fb := &fakeBackend{out: `sure: {"recap":"held focus on the port","carry_forward":"start in the editor next time"}`}
	refl, err := NewService(fb).Review(context.Background(), "f", "h")
	if err != nil {
		t.Fatalf("review: %v", err)
	}
	if refl.Recap != "held focus on the port" || refl.CarryForward != "start in the editor next time" {
		t.Fatalf("bad reflection: %+v", refl)
	}
}

func TestReviewServiceBackendError(t *testing.T) {
	fb := &fakeBackend{err: errors.New("boom")}
	if _, err := NewService(fb).Review(context.Background(), "f", "h"); err == nil {
		t.Fatal("want backend error")
	}
}

func TestParseReflectionEmpty(t *testing.T) {
	if _, err := parseReflection(""); !errors.Is(err, ErrEmptyResponse) {
		t.Fatalf("want ErrEmptyResponse, got %v", err)
	}
}

func TestParseReflectionNoJSON(t *testing.T) {
	if _, err := parseReflection("I cannot help."); !errors.Is(err, ErrNoJSON) {
		t.Fatalf("want ErrNoJSON, got %v", err)
	}
}

func TestParseReflectionRequiresRecap(t *testing.T) {
	if _, err := parseReflection(`{"recap":"  ","carry_forward":"x"}`); !errors.Is(err, ErrInvalidReflection) {
		t.Fatalf("blank recap should be invalid, got %v", err)
	}
}

func TestParseReflectionAllowsEmptyCarryForward(t *testing.T) {
	refl, err := parseReflection(`{"recap":"did the thing","carry_forward":""}`)
	if err != nil {
		t.Fatalf("carry_forward may be empty: %v", err)
	}
	if refl.Recap != "did the thing" || refl.CarryForward != "" {
		t.Fatalf("bad reflection: %+v", refl)
	}
}