package chat

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

// A Request may carry its own transcript budget. The Service's cap (18,000 chars by
// default) is sized for YouTube captions; an uploaded recording is much longer
// (~50,000 chars an hour), and keeping only the head of it would answer questions
// about the last two-thirds of a meeting from text that does not contain them
// (ADR-033). The per-request value overrides; zero means "the service default".

func TestAnswerMaxCharsOverridesTheServiceCap(t *testing.T) {
	tests := []struct {
		name          string
		serviceCap    int
		requestCap    int
		transcriptLen int
		wantKept      int
		wantTruncated bool
	}{
		{"request cap above the service cap keeps the whole transcript", 10, 100, 50, 50, false},
		{"request cap below the service cap bounds tighter", 100, 10, 50, 10, true},
		{"zero request cap falls back to the service cap", 20, 0, 50, 20, true},
		{"negative request cap is treated as unset", 20, -1, 50, 20, true},
		{"request cap exceeded is reported as truncated", 10, 30, 50, 30, true},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			f := &factory{answer: "answer"}
			s := New(f.make, []string{"koala/phi4-mini"}, tt.serviceCap)

			reply, err := s.Answer(context.Background(), Request{
				Model:      "koala/phi4-mini",
				Transcript: strings.Repeat("x", tt.transcriptLen),
				Question:   "what was decided?",
				MaxChars:   tt.requestCap,
			})
			if err != nil {
				t.Fatalf("Answer: %v", err)
			}
			if got := strings.Count(f.used.lastSystem, "x"); got != tt.wantKept {
				t.Errorf("transcript chars sent = %d, want %d", got, tt.wantKept)
			}
			if reply.Truncated != tt.wantTruncated {
				t.Errorf("Truncated = %v, want %v", reply.Truncated, tt.wantTruncated)
			}
		})
	}
}