package main

// Bulk scan-state tests (faceted plan Part 2 Phase 3): the scanner's
// one-query-per-library bulk load replaces the per-file
// GetMediaItemByFilePath flood. Behavioral equivalence asserted at the
// container level: unchanged rescans skip (updated_at stable), items
// created OUTSIDE the scanner (API create path) are seen by the bulk
// load, and size changes still take the update path.

import (
	"context"
	"crypto/sha256"
	"encoding/hex"
	"fmt"
	"os"
	"path/filepath"
	"testing"
	"time"

	"bookhoard/internal/database"

	"github.com/jackc/pgx/v5/pgtype"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestScanStateBulkLoad(t *testing.T) {
	setup := setupTestServer(t)
	t.Cleanup(func() { _ = setup.Close() })

	admin, _ := moveTestAdminID(t, setup)
	libID, folder := createTypedTestLibrary(t, setup, fmt.Sprintf("Test Scan State %d", time.Now().UnixNano()), "ebooks")
	t.Cleanup(func() { deleteLibraries(t, setup, libID) })

	// Two scanner-created fixture books.
	epubA := filepath.Join(folder, "Author A", "State Book A", "book.epub")
	require.NoError(t, os.MkdirAll(filepath.Dir(epubA), 0755))
	require.NoError(t, os.WriteFile(epubA, []byte("state book A content"), 0644))
	epubB := filepath.Join(folder, "Author B", "State Book B", "book.epub")
	require.NoError(t, os.MkdirAll(filepath.Dir(epubB), 0755))
	require.NoError(t, os.WriteFile(epubB, []byte("state book B content"), 0644))

	scanTestFolder(t, setup, admin, folder)

	items := listLibraryAudioItems(t, setup, libID)
	require.Len(t, items, 2, "both books ingested")
	var updatedA time.Time
	for _, item := range items {
		switch item.Title {
		case "State Book A":
			updatedA = item.UpdatedAt.Time
		case "State Book B":
		default:
			t.Errorf("unexpected item %q", item.Title)
		}
	}
	require.False(t, updatedA.IsZero())

	// Unchanged rescan: the skip path must not touch the rows.
	scanTestFolder(t, setup, admin, folder)
	items = listLibraryAudioItems(t, setup, libID)
	require.Len(t, items, 2, "no duplicates on rescan")
	for _, item := range items {
		if item.Title == "State Book A" {
			assert.Equal(t, updatedA, item.UpdatedAt.Time, "unchanged rescan leaves updated_at stable")
		}
	}

	// A row created by the API create path (NOT by a scan) must be seen
	// by the bulk load: the rescan skips it instead of re-creating. The
	// file must really exist (the archive pass missing-checks rows
	// whose files are absent).
	apiFile := filepath.Join(folder, "Author C", "API Made Book", "book.epub")
	require.NoError(t, os.MkdirAll(filepath.Dir(apiFile), 0755))
	require.NoError(t, os.WriteFile(apiFile, []byte("api made book content"), 0644))
	apiStat, err := os.Stat(apiFile)
	require.NoError(t, err)
	created, err := setup.DB.CreateMediaItem(context.Background(), database.CreateMediaItemParams{
		LibraryID: libID,
		Title:     "API Made Book",
		Authors:   []string{"API Author"},
		FilePath:  "Author C/API Made Book/book.epub",
		FileSize:  pgtype.Int8{Int64: apiStat.Size(), Valid: true},
		MimeType:  pgtype.Text{String: "application/epub+zip", Valid: true},
	})
	require.NoError(t, err)
	// Stamp the file's real sha the way the scanner does — otherwise the
	// skip path's one-time hash self-heal fires and bumps updated_at.
	// The identifiers UPDATE also bumps updated_at, so read the row
	// AFTER the stamp for the baseline.
	apiSha := sha256.Sum256([]byte("api made book content"))
	stamped, err := setup.DB.UpdateMediaItemIdentifiers(context.Background(), database.UpdateMediaItemIdentifiersParams{
		ID:         created.ID,
		FileSha256: pgtype.Text{String: hex.EncodeToString(apiSha[:]), Valid: true},
	})
	require.NoError(t, err)
	apiUpdated := stamped.UpdatedAt.Time

	scanTestFolder(t, setup, admin, folder)
	items = listLibraryAudioItems(t, setup, libID)
	require.Len(t, items, 3, "API-created item survives the rescan as-is")
	for _, item := range items {
		if item.Title == "API Made Book" {
			assert.Equal(t, apiUpdated, item.UpdatedAt.Time, "bulk-loaded state sees scanner-external rows; skip path leaves them alone")
		}
	}

	// Size change: the update path still fires (with a fresh full-row
	// read + hash recompute, then a write-through of the new size).
	require.NoError(t, os.WriteFile(epubA, []byte("state book A content — now longer"), 0644))
	scanTestFolder(t, setup, admin, folder)
	items = listLibraryAudioItems(t, setup, libID)
	require.Len(t, items, 3, "size change updates in place, never duplicates")
	for _, item := range items {
		if item.Title == "State Book A" {
			assert.NotEqual(t, updatedA, item.UpdatedAt.Time, "size change takes the update path")
		}
	}
}