package service

import (
	"context"
	"errors"
	"os"
	"path/filepath"
	"testing"
	"time"

	"internal-mail-skill/internal/db"
	"internal-mail-skill/internal/model"
	mailsmtp "internal-mail-skill/internal/smtp"
)

func TestThreadAssemblyLinksReferences(t *testing.T) {
	ctx := context.Background()
	store, err := db.Open(":memory:")
	if err != nil {
		t.Fatal(err)
	}
	defer store.Close()
	if err := store.Migrate(ctx); err != nil {
		t.Fatal(err)
	}
	svc := New(store, nil, nil, "default")

	root, err := svc.SaveParsedEmail(ctx, SaveEmailInput{
		POP3UID: "uid-root",
		Parsed: model.ParsedEmail{
			MessageIDHeader: "<root@example.com>",
			Subject:         "Root",
			SenderEmail:     "a@example.com",
		},
	})
	if err != nil {
		t.Fatal(err)
	}
	reply, err := svc.SaveParsedEmail(ctx, SaveEmailInput{
		POP3UID: "uid-reply",
		Parsed: model.ParsedEmail{
			MessageIDHeader: "<reply@example.com>",
			InReplyTo:       "<root@example.com>",
			References:      "<root@example.com>",
			Subject:         "Re: Root",
			SenderEmail:     "b@example.com",
		},
	})
	if err != nil {
		t.Fatal(err)
	}

	thread, err := svc.GetThread(ctx, reply)
	if err != nil {
		t.Fatal(err)
	}
	if len(thread) != 2 || thread[0].ID != root || thread[1].ID != reply {
		t.Fatalf("thread = %#v", thread)
	}
}

func TestSearchMarkLabelsAndDraftLifecycle(t *testing.T) {
	ctx := context.Background()
	store, err := db.Open(":memory:")
	if err != nil {
		t.Fatal(err)
	}
	defer store.Close()
	if err := store.Migrate(ctx); err != nil {
		t.Fatal(err)
	}
	svc := New(store, nil, nil, "default")

	emailID, err := svc.SaveParsedEmail(ctx, SaveEmailInput{
		POP3UID: "uid-1",
		Parsed: model.ParsedEmail{
			MessageIDHeader: "<m@example.com>",
			Subject:         "Quarterly Plan",
			BodyText:        "Please review",
			SenderEmail:     "boss@example.com",
		},
	})
	if err != nil {
		t.Fatal(err)
	}
	if err := svc.MarkEmail(ctx, emailID, MarkInput{Read: boolPtr(true), Processed: boolPtr(true)}); err != nil {
		t.Fatal(err)
	}
	label, err := svc.CreateLabel(ctx, "work", "#336699")
	if err != nil {
		t.Fatal(err)
	}
	if err := svc.ApplyLabels(ctx, []int64{emailID}, []int64{label.ID}, "add"); err != nil {
		t.Fatal(err)
	}
	results, err := svc.SearchEmails(ctx, SearchFilters{Q: "Quarterly", Read: boolPtr(true), Limit: 10})
	if err != nil {
		t.Fatal(err)
	}
	if len(results) != 1 || results[0].Labels[0].Name != "work" {
		t.Fatalf("search results = %#v", results)
	}

	draft, err := svc.CreateDraft(ctx, DraftInput{To: []string{"x@example.com"}, Subject: "Draft", Body: "Hi"})
	if err != nil {
		t.Fatal(err)
	}
	updated, err := svc.UpdateDraft(ctx, draft.ID, DraftInput{To: []string{"x@example.com"}, Subject: "Updated", Body: "Hello"})
	if err != nil {
		t.Fatal(err)
	}
	if updated.Subject != "Updated" {
		t.Fatalf("updated subject = %q", updated.Subject)
	}
}

func TestSaveParsedEmailRollsBackWhenAttachmentStorageFails(t *testing.T) {
	ctx := context.Background()
	store, err := db.Open(":memory:")
	if err != nil {
		t.Fatal(err)
	}
	defer store.Close()
	if err := store.Migrate(ctx); err != nil {
		t.Fatal(err)
	}
	dir := t.TempDir()
	blocker := filepath.Join(dir, "attachments-blocker")
	if err := os.WriteFile(blocker, []byte("not a directory"), 0600); err != nil {
		t.Fatal(err)
	}
	svc := NewWithOptions(store, nil, nil, "default", Options{AttachmentDir: blocker})

	_, err = svc.SaveParsedEmail(ctx, SaveEmailInput{
		POP3UID: "uid-broken-attachment",
		Parsed: model.ParsedEmail{
			MessageIDHeader: "<broken@example.com>",
			Subject:         "Broken Attachment",
			SenderEmail:     "a@example.com",
			Attachments: []model.ParsedAttachment{{
				Filename:    "note.txt",
				ContentType: "text/plain",
				SizeBytes:   4,
				Data:        []byte("nope"),
			}},
		},
	})
	if err == nil {
		t.Fatal("SaveParsedEmail() error = nil, want attachment storage failure")
	}

	results, err := svc.SearchEmails(ctx, SearchFilters{Q: "Broken Attachment", Limit: 10})
	if err != nil {
		t.Fatal(err)
	}
	if len(results) != 0 {
		t.Fatalf("failed save left searchable message: %#v", results)
	}
}

func TestSendDraftIsIdempotentAfterSuccess(t *testing.T) {
	ctx := context.Background()
	store, err := db.Open(":memory:")
	if err != nil {
		t.Fatal(err)
	}
	defer store.Close()
	if err := store.Migrate(ctx); err != nil {
		t.Fatal(err)
	}
	mailer := &fakeMailer{}
	svc := NewWithOptions(store, nil, mailer, "default", Options{FromAddress: "sender@example.com"})

	draft, err := svc.CreateDraft(ctx, DraftInput{To: []string{"x@example.com"}, Subject: "Once", Body: "hello"})
	if err != nil {
		t.Fatal(err)
	}
	first, err := svc.SendDraft(ctx, draft.ID)
	if err != nil {
		t.Fatal(err)
	}
	second, err := svc.SendDraft(ctx, draft.ID)
	if err != nil {
		t.Fatal(err)
	}
	if mailer.calls != 1 {
		t.Fatalf("mailer calls = %d, want 1", mailer.calls)
	}
	if second.SentMessage.ID != first.SentMessage.ID {
		t.Fatalf("second send message id = %d, want %d", second.SentMessage.ID, first.SentMessage.ID)
	}
}

func boolPtr(v bool) *bool { return &v }

type fakeMailer struct {
	calls int
	err   error
}

func (f *fakeMailer) Send(ctx context.Context, req mailsmtp.SendRequest) (mailsmtp.SendResult, error) {
	f.calls++
	if f.err != nil {
		return mailsmtp.SendResult{}, f.err
	}
	if req.FromAddress == "" {
		return mailsmtp.SendResult{}, errors.New("from required")
	}
	return mailsmtp.SendResult{MessageIDHeader: "<sent@example.com>", SentAt: time.Now().UTC()}, nil
}