package config

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

func TestLoadSessionWithOptionsRendersCompactPlaceholder(t *testing.T) {
	dir := t.TempDir()
	sessionPath := filepath.Join(dir, "session.yml")
	sessionYAML := `session_id: "{{session_id}}"
campaign: sample-campaign
inputs:
  audio_dir: ./audio
  speakers_file: ./speakers.yml
  autocorrect_file: ./autocorrect.yml
  glossary_file: ./glossary.yml
`
	if err := os.WriteFile(sessionPath, []byte(sessionYAML), 0o644); err != nil {
		t.Fatalf("write session.yml: %v", err)
	}

	cfg, err := LoadSessionWithOptions(sessionPath, SessionLoadOptions{SessionID: "2026-04-04"})
	if err != nil {
		t.Fatalf("LoadSessionWithOptions() error = %v", err)
	}
	if cfg.SessionID != "2026-04-04" {
		t.Fatalf("SessionID = %q, want 2026-04-04", cfg.SessionID)
	}
}

func TestLoadSessionWithOptionsRendersSpacedPlaceholder(t *testing.T) {
	dir := t.TempDir()
	sessionPath := filepath.Join(dir, "session.yml")
	sessionYAML := `session_id: "{{ session_id }}"
campaign: sample-campaign
inputs:
  audio_dir: ./audio
  speakers_file: ./speakers.yml
  autocorrect_file: ./autocorrect.yml
  glossary_file: ./glossary.yml
`
	if err := os.WriteFile(sessionPath, []byte(sessionYAML), 0o644); err != nil {
		t.Fatalf("write session.yml: %v", err)
	}

	cfg, err := LoadSessionWithOptions(sessionPath, SessionLoadOptions{SessionID: "2026-04-04"})
	if err != nil {
		t.Fatalf("LoadSessionWithOptions() error = %v", err)
	}
	if cfg.SessionID != "2026-04-04" {
		t.Fatalf("SessionID = %q, want 2026-04-04", cfg.SessionID)
	}
}

func TestLoadSessionWithOptionsRendersPreviousSessionPlaceholder(t *testing.T) {
	dir := t.TempDir()
	sessionPath := filepath.Join(dir, "session.yml")
	sessionYAML := `session_id: "{{ session_id }}"
previous_session_id: "{{ previous_session_id }}"
campaign: sample-campaign
inputs:
  audio_dir: ./audio
  speakers_file: ./speakers.yml
  autocorrect_file: ./autocorrect.yml
  glossary_file: ./glossary.yml
`
	if err := os.WriteFile(sessionPath, []byte(sessionYAML), 0o644); err != nil {
		t.Fatalf("write session.yml: %v", err)
	}

	cfg, err := LoadSessionWithOptions(sessionPath, SessionLoadOptions{
		SessionID:         "2026-04-04",
		PreviousSessionID: "2026-03-28",
	})
	if err != nil {
		t.Fatalf("LoadSessionWithOptions() error = %v", err)
	}
	if cfg.PreviousSessionID != "2026-03-28" {
		t.Fatalf("PreviousSessionID = %q, want 2026-03-28", cfg.PreviousSessionID)
	}
}

func TestLoadSessionWithOptionsUnresolvedPlaceholderFails(t *testing.T) {
	dir := t.TempDir()
	sessionPath := filepath.Join(dir, "session.yml")
	sessionYAML := `session_id: "{{ session_id }}"
campaign: sample-campaign
inputs:
  audio_dir: ./audio
  speakers_file: ./speakers.yml
  autocorrect_file: ./autocorrect.yml
  glossary_file: ./glossary.yml
`
	if err := os.WriteFile(sessionPath, []byte(sessionYAML), 0o644); err != nil {
		t.Fatalf("write session.yml: %v", err)
	}

	_, err := LoadSessionWithOptions(sessionPath, SessionLoadOptions{})
	if err == nil {
		t.Fatal("expected error, got nil")
	}
	if !strings.Contains(err.Error(), "unresolved template variable") {
		t.Fatalf("error = %q, want unresolved-variable context", err.Error())
	}
	if !strings.Contains(err.Error(), "session_id") {
		t.Fatalf("error = %q, want session_id variable", err.Error())
	}
}

func TestLoadSessionWithOptionsUnresolvedPreviousSessionPlaceholderFails(t *testing.T) {
	dir := t.TempDir()
	sessionPath := filepath.Join(dir, "session.yml")
	sessionYAML := `session_id: 2026-05-03
previous_session_id: "{{ previous_session_id }}"
campaign: sample-campaign
inputs:
  audio_dir: ./audio
  speakers_file: ./speakers.yml
  autocorrect_file: ./autocorrect.yml
  glossary_file: ./glossary.yml
`
	if err := os.WriteFile(sessionPath, []byte(sessionYAML), 0o644); err != nil {
		t.Fatalf("write session.yml: %v", err)
	}

	_, err := LoadSessionWithOptions(sessionPath, SessionLoadOptions{})
	if err == nil {
		t.Fatal("expected error, got nil")
	}
	if !strings.Contains(err.Error(), "unresolved template variable") {
		t.Fatalf("error = %q, want unresolved-variable context", err.Error())
	}
	if !strings.Contains(err.Error(), "previous_session_id") {
		t.Fatalf("error = %q, want previous_session_id variable", err.Error())
	}
	if !strings.Contains(err.Error(), "--previous-session-id") {
		t.Fatalf("error = %q, want previous-session-id guidance", err.Error())
	}
}

func TestLoadSessionWithOptionsMismatchFails(t *testing.T) {
	dir := t.TempDir()
	sessionPath := filepath.Join(dir, "session.yml")
	sessionYAML := `session_id: 2026-05-03
campaign: sample-campaign
inputs:
  audio_dir: ./audio
  speakers_file: ./speakers.yml
  autocorrect_file: ./autocorrect.yml
  glossary_file: ./glossary.yml
`
	if err := os.WriteFile(sessionPath, []byte(sessionYAML), 0o644); err != nil {
		t.Fatalf("write session.yml: %v", err)
	}

	_, err := LoadSessionWithOptions(sessionPath, SessionLoadOptions{SessionID: "2026-04-04"})
	if err == nil {
		t.Fatal("expected error, got nil")
	}
	if !strings.Contains(err.Error(), "session_id mismatch") {
		t.Fatalf("error = %q, want mismatch context", err.Error())
	}
}

func TestLoadSessionWithOptionsPreviousSessionMismatchFails(t *testing.T) {
	dir := t.TempDir()
	sessionPath := filepath.Join(dir, "session.yml")
	sessionYAML := `session_id: 2026-05-03
previous_session_id: 2026-04-26
campaign: sample-campaign
inputs:
  audio_dir: ./audio
  speakers_file: ./speakers.yml
  autocorrect_file: ./autocorrect.yml
  glossary_file: ./glossary.yml
`
	if err := os.WriteFile(sessionPath, []byte(sessionYAML), 0o644); err != nil {
		t.Fatalf("write session.yml: %v", err)
	}

	_, err := LoadSessionWithOptions(sessionPath, SessionLoadOptions{
		SessionID:         "2026-05-03",
		PreviousSessionID: "2026-04-25",
	})
	if err == nil {
		t.Fatal("expected error, got nil")
	}
	if !strings.Contains(err.Error(), "previous_session_id mismatch") {
		t.Fatalf("error = %q, want mismatch context", err.Error())
	}
}

func TestLoadSessionWithOptionsUnknownFieldStillRejectedAfterRendering(t *testing.T) {
	dir := t.TempDir()
	sessionPath := filepath.Join(dir, "session.yml")
	sessionYAML := `session_id: "{{ session_id }}"
campaign: sample-campaign
unknown_field: true
inputs:
  audio_dir: ./audio
  speakers_file: ./speakers.yml
  autocorrect_file: ./autocorrect.yml
  glossary_file: ./glossary.yml
`
	if err := os.WriteFile(sessionPath, []byte(sessionYAML), 0o644); err != nil {
		t.Fatalf("write session.yml: %v", err)
	}

	_, err := LoadSessionWithOptions(sessionPath, SessionLoadOptions{SessionID: "2026-04-04"})
	if err == nil {
		t.Fatal("expected error, got nil")
	}
	if !strings.Contains(err.Error(), "strict decode failed") {
		t.Fatalf("error = %q, want strict-decode context", err.Error())
	}
}

func TestLoadSessionWithOptionsConcreteSessionStillLoads(t *testing.T) {
	dir := t.TempDir()
	sessionPath := filepath.Join(dir, "session.yml")
	sessionYAML := `session_id: 2026-05-03
campaign: sample-campaign
inputs:
  audio_dir: ./audio
  speakers_file: ./speakers.yml
  autocorrect_file: ./autocorrect.yml
  glossary_file: ./glossary.yml
`
	if err := os.WriteFile(sessionPath, []byte(sessionYAML), 0o644); err != nil {
		t.Fatalf("write session.yml: %v", err)
	}

	cfg, err := LoadSessionWithOptions(sessionPath, SessionLoadOptions{})
	if err != nil {
		t.Fatalf("LoadSessionWithOptions() error = %v", err)
	}
	if cfg.SessionID != "2026-05-03" {
		t.Fatalf("SessionID = %q, want 2026-05-03", cfg.SessionID)
	}
}

func TestLoadSessionBytesWithOptionsUsesSameTemplateAndStrictDecode(t *testing.T) {
	sessionYAML := []byte(`session_id: "{{ session_id }}"
campaign: sample-campaign
inputs:
  audio_s3:
    prefix: audio/
`)

	cfg, err := LoadSessionBytesWithOptions("s3://bucket/session.yml", sessionYAML, SessionLoadOptions{SessionID: "2026-05-03"})
	if err != nil {
		t.Fatalf("LoadSessionBytesWithOptions() error = %v", err)
	}
	if cfg.SessionID != "2026-05-03" {
		t.Fatalf("SessionID = %q, want 2026-05-03", cfg.SessionID)
	}

	_, err = LoadSessionBytesWithOptions("s3://bucket/session.yml", []byte("session_id: 2026-05-03\nunknown: true\n"), SessionLoadOptions{})
	if err == nil {
		t.Fatal("expected strict decode error, got nil")
	}
	if !strings.Contains(err.Error(), "strict decode failed") {
		t.Fatalf("error = %q, want strict decode context", err.Error())
	}
}

func TestLoadSessionBytesWithOptionsMismatchFails(t *testing.T) {
	_, err := LoadSessionBytesWithOptions("s3://bucket/session.yml", []byte("session_id: 2026-05-03\n"), SessionLoadOptions{SessionID: "2026-04-04"})
	if err == nil {
		t.Fatal("expected mismatch error, got nil")
	}
	if !strings.Contains(err.Error(), "session_id mismatch") {
		t.Fatalf("error = %q, want mismatch context", err.Error())
	}
}