//go:build integration

package integration_test

import (
	"bytes"
	"context"
	"encoding/json"
	"io"
	"log/slog"
	"mime/multipart"
	"net/http"
	"net/http/httptest"
	"testing"
	"time"

	"github.com/alchemistkay/guestguard/internal/api"
	"github.com/alchemistkay/guestguard/internal/storage"
)

// TestCsvImportFlow walks the happy path: preview, then commit, then a
// re-import to confirm dedup is honoured.
func TestCsvImportFlow(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping integration test in -short mode")
	}
	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Minute)
	t.Cleanup(cancel)

	srv, db, host, token := setupAuthedAPI(t, ctx)
	eventID := createEvent(t, srv.URL, token, "Import Event", "import-event")
	_ = host

	const csvOne = `name,email,phone,plus_ones
Alex,alex@example.test,+447700900111,1
Sam,sam@example.test,,0
Jordan,,+15551234567,2
,,,
Mira,malformed-email,,0
`

	// Preview.
	var preview struct {
		Rows       []map[string]any `json:"rows"`
		Errors     []map[string]any `json:"errors"`
		TotalCount int              `json:"total_count"`
	}
	resp := postMultipart(t, srv.URL+"/events/"+eventID.String()+"/guests/import/preview", token, csvOne)
	must(t, json.NewDecoder(resp.Body).Decode(&preview), "decode preview")
	resp.Body.Close()
	if len(preview.Rows) != 3 {
		t.Fatalf("preview rows: got %d want 3 (errors=%+v)", len(preview.Rows), preview.Errors)
	}
	if len(preview.Errors) != 1 {
		t.Fatalf("preview errors: got %d want 1: %+v", len(preview.Errors), preview.Errors)
	}

	// Commit.
	var commit struct {
		Added         int      `json:"added"`
		Skipped       int      `json:"skipped"`
		SkippedEmails []string `json:"skipped_emails"`
	}
	resp = postMultipart(t, srv.URL+"/events/"+eventID.String()+"/guests/import", token, csvOne)
	must(t, json.NewDecoder(resp.Body).Decode(&commit), "decode commit")
	resp.Body.Close()
	if commit.Added != 3 || commit.Skipped != 0 {
		t.Fatalf("commit: added=%d skipped=%d (want 3/0)", commit.Added, commit.Skipped)
	}

	// Re-import the same file — emails should dedup.
	var commit2 struct {
		Added         int      `json:"added"`
		Skipped       int      `json:"skipped"`
		SkippedEmails []string `json:"skipped_emails"`
	}
	resp = postMultipart(t, srv.URL+"/events/"+eventID.String()+"/guests/import", token, csvOne)
	must(t, json.NewDecoder(resp.Body).Decode(&commit2), "decode commit2")
	resp.Body.Close()
	// Jordan has no email, so they re-import as a new row each time.
	// Alex + Sam have emails and should be skipped.
	if commit2.Skipped != 2 {
		t.Fatalf("re-import dedup: skipped=%d want 2 (added=%d)", commit2.Skipped, commit2.Added)
	}

	// Verify the row count in the DB matches expectations: 3 from first
	// commit + 1 (Jordan again) from second.
	var count int
	must(t, db.Pool.QueryRow(ctx,
		"SELECT count(*) FROM guests WHERE event_id = $1", eventID,
	).Scan(&count), "count guests")
	if count != 4 {
		t.Fatalf("guest count: got %d want 4", count)
	}
}

// TestCsvImportAtomicRollback verifies that a runtime error mid-batch
// leaves NO partial rows. We trigger this by injecting a name longer than
// the column allows (VARCHAR(255)) on row 3 of 4.
func TestCsvImportAtomicRollback(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping integration test in -short mode")
	}
	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Minute)
	t.Cleanup(cancel)

	srv, db, _, token := setupAuthedAPI(t, ctx)
	eventID := createEvent(t, srv.URL, token, "Atomic Event", "atomic-event")

	longName := bytes.Repeat([]byte("Aa"), 200) // 400 chars > VARCHAR(255)
	csv := "name,email\nAlice,a@example.test\nBob,b@example.test\n" +
		string(longName) + ",c@example.test\nDave,d@example.test\n"

	resp := postMultipart(t, srv.URL+"/events/"+eventID.String()+"/guests/import", token, csv)
	body, _ := io.ReadAll(resp.Body)
	resp.Body.Close()
	if resp.StatusCode != http.StatusInternalServerError {
		t.Fatalf("expected 500 on row insert error, got %d body=%s", resp.StatusCode, body)
	}

	var count int
	must(t, db.Pool.QueryRow(ctx,
		"SELECT count(*) FROM guests WHERE event_id = $1", eventID,
	).Scan(&count), "count after rollback")
	if count != 0 {
		t.Fatalf("expected 0 guests after rollback, got %d", count)
	}
}

// --- helpers shared with other tests in this dir ---

// setupAuthedAPI builds a fresh API server + a verified host + bearer
// token. Tests that just need a logged-in host can use this directly.
func setupAuthedAPI(t *testing.T, ctx context.Context) (srv *httptest.Server, db *storage.DB, hostID [16]byte, bearer string) {
	t.Helper()
	logger := slog.New(slog.NewTextHandler(io.Discard, nil))
	dsn := startPostgres(t, ctx)

	var err error
	db, err = storage.NewDB(ctx, dsn)
	must(t, err, "connect db")
	t.Cleanup(db.Close)
	must(t, db.Migrate(ctx), "migrate")

	apiSrv, err := api.NewServer(api.ServerDeps{
		Logger:               logger,
		DB:                   db,
		TokenTTL:             24 * time.Hour,
		JWTSecret:            testJWTSecret,
		JWTIssuer:            testJWTIssuer,
		AccessTokenTTL:       5 * time.Minute,
		RefreshTokenTTL:      24 * time.Hour,
		EmailVerificationTTL: 1 * time.Hour,
		PasswordResetTTL:     1 * time.Hour,
		PublicBaseURL:        "http://localhost",
	})
	must(t, err, "build api server")
	srv = httptest.NewServer(apiSrv.Handler())
	t.Cleanup(srv.Close)

	host := insertHost(t, ctx, db.Pool)
	hostID = host
	bearer = issueHostToken(t, host)
	return
}

func postMultipart(t *testing.T, url, bearer, body string) *http.Response {
	t.Helper()
	var buf bytes.Buffer
	mw := multipart.NewWriter(&buf)
	fw, err := mw.CreateFormFile("file", "guests.csv")
	must(t, err, "create form file")
	_, err = fw.Write([]byte(body))
	must(t, err, "write csv")
	must(t, mw.Close(), "close mw")

	req, err := http.NewRequest(http.MethodPost, url, &buf)
	must(t, err, "build req")
	req.Header.Set("Content-Type", mw.FormDataContentType())
	if bearer != "" {
		req.Header.Set("Authorization", "Bearer "+bearer)
	}
	resp, err := http.DefaultClient.Do(req)
	must(t, err, "do multipart")
	return resp
}