package store

import (
	"context"
	"testing"
	"time"
)

// seedBodyMessage stores one message with a body and a chosen received_at.
func seedBodyMessage(t *testing.T, s *Store, ctx context.Context, gmailID, body string, receivedAt time.Time) int64 {
	t.Helper()
	id, err := s.UpsertMessage(ctx, &Message{
		GmailID:       gmailID,
		FromAddr:      "sender@example.test",
		ToAddr:        "hello@where-woof.com",
		Subject:       "Subject " + gmailID,
		BodyText:      body,
		SourceAddress: "hello@where-woof.com",
		DateSent:      receivedAt,
		ReceivedAt:    receivedAt,
	})
	if err != nil {
		t.Fatalf("seed body message: %v", err)
	}
	return id
}

// bodyOf reads body_text directly, distinguishing NULL from empty.
func bodyOf(t *testing.T, s *Store, ctx context.Context, id int64) (string, bool) {
	t.Helper()
	var body *string
	if err := s.DB().QueryRowContext(ctx,
		`SELECT body_text FROM messages WHERE id = ?`, id).Scan(&body); err != nil {
		t.Fatalf("read body of message %d: %v", id, err)
	}
	if body == nil {
		return "", true
	}
	return *body, false
}

func TestRetainClearsOldBodiesKeepsMetadata(t *testing.T) {
	s, ctx := testStore(t)

	old := seedBodyMessage(t, s, ctx, "old-1", "an old body", time.Now().UTC().Add(-45*24*time.Hour))
	recent := seedBodyMessage(t, s, ctx, "recent-1", "a recent body", time.Now().UTC().Add(-2*24*time.Hour))

	res, err := s.Retain(ctx, RetentionPolicy{BodyMaxAge: 30 * 24 * time.Hour})
	if err != nil {
		t.Fatalf("Retain() error = %v", err)
	}
	if res.BodiesCleared != 1 {
		t.Errorf("BodiesCleared = %d, want 1", res.BodiesCleared)
	}

	if body, null := bodyOf(t, s, ctx, old); !null || body != "" {
		t.Errorf("old body = %q (null=%v), want NULL", body, null)
	}
	if body, null := bodyOf(t, s, ctx, recent); null || body != "a recent body" {
		t.Errorf("recent body = %q (null=%v), want unchanged", body, null)
	}

	// Metadata must survive the body clear.
	m, err := s.MessageByID(ctx, old)
	if err != nil {
		t.Fatalf("MessageByID() error = %v", err)
	}
	if m.Subject != "Subject old-1" || m.SourceAddress != "hello@where-woof.com" {
		t.Errorf("metadata lost after retention: %+v", m)
	}
	if m.BodyText != "" {
		t.Errorf("MessageByID().BodyText = %q, want empty", m.BodyText)
	}

	// A second pass is a no-op: the row is already NULL, not an empty string.
	res2, err := s.Retain(ctx, RetentionPolicy{BodyMaxAge: 30 * 24 * time.Hour})
	if err != nil {
		t.Fatalf("second Retain() error = %v", err)
	}
	if res2.BodiesCleared != 0 {
		t.Errorf("second BodiesCleared = %d, want 0", res2.BodiesCleared)
	}
}

func TestRetainCapsActionsLog(t *testing.T) {
	s, ctx := testStore(t)

	for i := 0; i < 5; i++ {
		if err := s.LogAction(ctx, "fetch", "scheduler", "pass"); err != nil {
			t.Fatalf("LogAction() %d error = %v", i, err)
		}
	}

	res, err := s.Retain(ctx, RetentionPolicy{ActionsLogMaxRows: 2})
	if err != nil {
		t.Fatalf("Retain() error = %v", err)
	}
	if res.ActionsDeleted != 3 {
		t.Errorf("ActionsDeleted = %d, want 3", res.ActionsDeleted)
	}

	entries, err := s.RecentActions(ctx, 100)
	if err != nil {
		t.Fatalf("RecentActions() error = %v", err)
	}
	if len(entries) != 2 {
		t.Fatalf("actions_log rows = %d, want 2", len(entries))
	}
	// RecentActions is newest-first; the two kept rows are the newest inserts.
	if entries[0].ID <= entries[1].ID {
		t.Errorf("kept rows not the newest: %d, %d", entries[0].ID, entries[1].ID)
	}

	// A smaller table than the cap is untouched.
	res2, err := s.Retain(ctx, RetentionPolicy{ActionsLogMaxRows: 50})
	if err != nil {
		t.Fatalf("second Retain() error = %v", err)
	}
	if res2.ActionsDeleted != 0 {
		t.Errorf("second ActionsDeleted = %d, want 0", res2.ActionsDeleted)
	}
}

func TestRetainDisabledPolicyIsNoOp(t *testing.T) {
	s, ctx := testStore(t)

	old := seedBodyMessage(t, s, ctx, "old-1", "an old body", time.Now().UTC().Add(-400*24*time.Hour))
	if err := s.LogAction(ctx, "fetch", "scheduler", "pass"); err != nil {
		t.Fatalf("LogAction() error = %v", err)
	}

	res, err := s.Retain(ctx, RetentionPolicy{})
	if err != nil {
		t.Fatalf("Retain() error = %v", err)
	}
	if res.BodiesCleared != 0 || res.ActionsDeleted != 0 {
		t.Errorf("disabled policy changed data: %+v", res)
	}
	if body, null := bodyOf(t, s, ctx, old); null || body != "an old body" {
		t.Errorf("old body = %q (null=%v), want unchanged", body, null)
	}
}