package app

import (
	"bytes"
	"context"
	"os"
	"path/filepath"
	"strings"
	"testing"
)

func TestSessionInitRejectsRenderedTemplateThatOmitsExpectedPreviousSession(t *testing.T) {
	workspaceRoot := t.TempDir()
	pipelinePath, campaignPath, _ := writeValidConfigFiles(t, workspaceRoot)
	campaignDir := filepath.Dir(campaignPath)
	templatePath := filepath.Join(campaignDir, "session.template.yml")
	template := `session_id: {{ session_id }}
campaign: sample-campaign
inputs:
  audio_dir: ./audio
`
	if err := os.WriteFile(templatePath, []byte(template), 0o644); err != nil {
		t.Fatalf("write session template: %v", err)
	}
	campaign := `campaign_id: sample-campaign
session_template_file: session.template.yml
inputs:
  speakers_file: ./speakers.yml
  autocorrect_file: ./autocorrect.yml
  glossary_file: ./glossary.yml
  players_file: ./players.yml
  party_file: ./party.yml
`
	if err := os.WriteFile(campaignPath, []byte(campaign), 0o644); err != nil {
		t.Fatalf("write campaign config: %v", err)
	}

	var out bytes.Buffer
	err := SessionInit(context.Background(), []string{
		"2026-05-03",
		"--config", pipelinePath,
		"--campaign-file", campaignPath,
		"--output", filepath.Join(t.TempDir(), "session.yml"),
		"--previous-session-id", "2026-04-26",
	}, &out)
	if err == nil {
		t.Fatal("expected error, got nil")
	}
	if !strings.Contains(err.Error(), "unused template variable value(s): previous_session_id") {
		t.Fatalf("SessionInit() error = %q, want missing previous-session template error", err.Error())
	}
}