package store_test

// Phase 6 Slice B — parity test between the legacy pgx-against-projax-
// items *Store and the new pgx-against-mbrian *MBrianReader.
//
// Skipped without SUPABASE_DATABASE_URL set. When run against the live
// post-migration database, every comparison should hold: the adapter
// must be a faithful translator of the migrated graph for projax UI
// consumers.

import (
	"context"
	"errors"
	"os"
	"sort"
	"testing"
	"time"

	"github.com/jackc/pgx/v5/pgxpool"

	"github.com/m/projax/store"
)

func newPair(t *testing.T) (*store.Store, *store.MBrianReader, *pgxpool.Pool) {
	t.Helper()
	url := os.Getenv("SUPABASE_DATABASE_URL")
	if url == "" {
		url = os.Getenv("PROJAX_DB_URL")
	}
	if url == "" {
		t.Skip("set SUPABASE_DATABASE_URL")
	}
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()
	pool, err := pgxpool.New(ctx, url)
	if err != nil {
		t.Fatalf("pool: %v", err)
	}
	if err := pool.Ping(ctx); err != nil {
		t.Skipf("DB unreachable: %v", err)
	}
	return store.New(pool), store.NewMBrianReader(pool), pool
}

// TestParityListAll: both readers return the same set of items by slug.
// Field-by-field equality is asserted for slug/title/status/tags/management/
// public/parent count/paths — the consumer-facing surface.
func TestParityListAll(t *testing.T) {
	s, r, pool := newPair(t)
	defer pool.Close()
	ctx := context.Background()

	leg, err := s.ListAll(ctx)
	if err != nil {
		t.Fatalf("store ListAll: %v", err)
	}
	mb, err := r.ListAll(ctx)
	if err != nil {
		t.Fatalf("mbrian ListAll: %v", err)
	}
	if len(leg) != len(mb) {
		t.Fatalf("count mismatch: store=%d mbrian=%d", len(leg), len(mb))
	}
	// Per the migration brief, two projax-side squatter slugs were
	// renamed-aside (not deleted) so mBrian could take the canonical
	// 'work' (area) + 'dania' (project) slugs. Compare every slug that
	// resolves in BOTH sets; the squatters surface as legacy-only.
	skip := map[string]bool{"work": true, "dania": true}
	legBySlug := bySlug(leg)
	mbBySlug := bySlug(mb)
	for slug, l := range legBySlug {
		if skip[slug] {
			continue
		}
		m, ok := mbBySlug[slug]
		if !ok {
			t.Errorf("slug %q missing in mBrian set", slug)
			continue
		}
		if l.Title != m.Title {
			t.Errorf("%s title: store=%q mbrian=%q", slug, l.Title, m.Title)
		}
		if l.Status != m.Status {
			t.Errorf("%s status: store=%q mbrian=%q", slug, l.Status, m.Status)
		}
		if !sameSet(l.Tags, m.Tags) {
			t.Errorf("%s tags: store=%v mbrian=%v", slug, l.Tags, m.Tags)
		}
		if !sameSet(l.Management, m.Management) {
			t.Errorf("%s management: store=%v mbrian=%v", slug, l.Management, m.Management)
		}
		if l.Public != m.Public {
			t.Errorf("%s public: store=%v mbrian=%v", slug, l.Public, m.Public)
		}
		if len(l.ParentIDs) != len(m.ParentIDs) {
			t.Errorf("%s parent count: store=%d mbrian=%d",
				slug, len(l.ParentIDs), len(m.ParentIDs))
		}
		if !sameSet(l.Paths, m.Paths) {
			t.Errorf("%s paths: store=%v mbrian=%v", slug, l.Paths, m.Paths)
		}
	}
}

// TestParitySpotChecks asserts the 5 spot-check items resolve identically
// through both readers — root area / single-parent / multi-parent /
// caldav-linked / public-listing populated.
func TestParitySpotChecks(t *testing.T) {
	s, r, pool := newPair(t)
	defer pool.Close()
	ctx := context.Background()
	for _, slug := range []string{"dev", "work", "paliad", "services", "mhome", "fdbck", "dania"} {
		l, lerr := s.GetByPathOrSlug(ctx, slug)
		m, merr := r.GetByPathOrSlug(ctx, slug)
		if lerr != nil && merr != nil {
			// Both 404 — consistent.
			continue
		}
		if lerr != nil {
			t.Errorf("%s: store err=%v but mbrian found", slug, lerr)
			continue
		}
		if merr != nil {
			t.Errorf("%s: mbrian err=%v but store found", slug, merr)
			continue
		}
		if l.Slug != m.Slug || l.Title != m.Title {
			t.Errorf("%s: shape mismatch store=%+v mbrian=%+v",
				slug, l.Slug+"/"+l.Title, m.Slug+"/"+m.Title)
		}
	}
}

// TestParityCalDAVLinks: the single caldav-list link must round-trip.
func TestParityCalDAVLinks(t *testing.T) {
	s, r, pool := newPair(t)
	defer pool.Close()
	ctx := context.Background()
	leg, err := s.LinksByRefType(ctx, "caldav-list")
	if err != nil {
		t.Fatalf("store: %v", err)
	}
	mb, err := r.LinksByRefType(ctx, "caldav-list")
	if err != nil {
		t.Fatalf("mbrian: %v", err)
	}
	if len(leg) != len(mb) {
		t.Errorf("count: store=%d mbrian=%d", len(leg), len(mb))
	}
	// The URLs must round-trip identically. Match by ref_id.
	legByRef := map[string]*store.ItemLink{}
	for _, l := range leg {
		legByRef[l.RefID] = l
	}
	for _, m := range mb {
		l, ok := legByRef[m.RefID]
		if !ok {
			t.Errorf("mbrian caldav RefID %q not in store set", m.RefID)
			continue
		}
		if l.Rel != m.Rel {
			t.Errorf("caldav %s rel: store=%q mbrian=%q", m.RefID, l.Rel, m.Rel)
		}
	}
}

// TestParityGiteaRepoLinks — same parity check for the 37 gitea-repo edges.
func TestParityGiteaRepoLinks(t *testing.T) {
	s, r, pool := newPair(t)
	defer pool.Close()
	ctx := context.Background()
	leg, err := s.LinksByRefType(ctx, "gitea-repo")
	if err != nil {
		t.Fatalf("store: %v", err)
	}
	mb, err := r.LinksByRefType(ctx, "gitea-repo")
	if err != nil {
		t.Fatalf("mbrian: %v", err)
	}
	if len(leg) != len(mb) {
		t.Errorf("count: store=%d mbrian=%d", len(leg), len(mb))
	}
	legSeen := map[string]bool{}
	for _, l := range leg {
		legSeen[l.RefID] = true
	}
	for _, m := range mb {
		if !legSeen[m.RefID] {
			t.Errorf("mbrian gitea-repo RefID %q not in store set", m.RefID)
		}
	}
}

// TestParityAllTags: tag union must match (modulo ordering).
func TestParityAllTags(t *testing.T) {
	s, r, pool := newPair(t)
	defer pool.Close()
	ctx := context.Background()
	leg, err := s.AllTags(ctx)
	if err != nil {
		t.Fatalf("store: %v", err)
	}
	mb, err := r.AllTags(ctx)
	if err != nil {
		t.Fatalf("mbrian: %v", err)
	}
	if !sameSet(leg, mb) {
		t.Errorf("AllTags mismatch:\n  store=%v\n  mbrian=%v", leg, mb)
	}
}

// TestParityNotFound: an unknown slug must 404 from both.
func TestParityNotFound(t *testing.T) {
	s, r, pool := newPair(t)
	defer pool.Close()
	ctx := context.Background()
	_, le := s.GetByPathOrSlug(ctx, "definitely-not-a-real-slug-zzzzz")
	_, me := r.GetByPathOrSlug(ctx, "definitely-not-a-real-slug-zzzzz")
	if !errors.Is(le, store.ErrNotFound) {
		t.Errorf("store should ErrNotFound, got %v", le)
	}
	if !errors.Is(me, store.ErrNotFound) {
		t.Errorf("mbrian should ErrNotFound, got %v", me)
	}
}

// --- helpers ---

func bySlug(items []*store.Item) map[string]*store.Item {
	out := map[string]*store.Item{}
	for _, it := range items {
		out[it.Slug] = it
	}
	return out
}

func sameSet(a, b []string) bool {
	if len(a) != len(b) {
		return false
	}
	ac := append([]string{}, a...)
	bc := append([]string{}, b...)
	sort.Strings(ac)
	sort.Strings(bc)
	for i := range ac {
		if ac[i] != bc[i] {
			return false
		}
	}
	return true
}