// internal/ai/ambient_test.go
package ai

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

func TestServiceAmbientDriftSuccess(t *testing.T) {
	fb := &fakeBackend{out: `{"drifting": true, "message": "deep in YouTube, none of today's goals"}`}
	line, err := NewService(fb).AmbientDrift(context.Background(), "## Goals\nship keel", []string{"YouTube - Brave"})
	if err != nil {
		t.Fatalf("ambient drift: %v", err)
	}
	if line == "" {
		t.Fatal("expected a non-empty drift line")
	}
	if !strings.Contains(fb.gotPrompt, "ship keel") {
		t.Fatalf("prompt should embed the frame, got: %s", fb.gotPrompt)
	}
	if !strings.Contains(fb.gotPrompt, "YouTube - Brave") {
		t.Fatalf("prompt should embed the recent titles, got: %s", fb.gotPrompt)
	}
}

func TestServiceAmbientDriftBackendError(t *testing.T) {
	fb := &fakeBackend{err: errors.New("boom")}
	if _, err := NewService(fb).AmbientDrift(context.Background(), "frame", []string{"x"}); err == nil {
		t.Fatal("want backend error")
	}
}

func TestParseAmbientDrift(t *testing.T) {
	tests := []struct {
		name    string
		in      string
		want    string
		wantErr error
	}{
		{"on track yields empty", `{"drifting": false, "message": ""}`, "", nil},
		{"drift returns message", `{"drifting": true, "message": "watching unrelated videos"}`, "watching unrelated videos", nil},
		{"drift is trimmed", `{"drifting": true, "message": "  slid  "}`, "slid", nil},
		{"drift without message degrades to silence", `{"drifting": true, "message": ""}`, "", nil},
		{"json embedded in prose", `ok: {"drifting": true, "message": "off track"} done`, "off track", nil},
		{"empty response", "   ", "", ErrEmptyResponse},
		{"no json", "no braces here", "", ErrNoJSON},
		{"malformed json", `{"drifting": true, "message":`, "", ErrInvalidAmbientDrift},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got, err := parseAmbientDrift(tt.in)
			if tt.wantErr != nil {
				if !errors.Is(err, tt.wantErr) {
					t.Fatalf("err = %v, want %v", err, tt.wantErr)
				}
				return
			}
			if err != nil {
				t.Fatalf("unexpected err: %v", err)
			}
			if got != tt.want {
				t.Fatalf("got %q, want %q", got, tt.want)
			}
		})
	}
}