package store

import (
	"context"
	"database/sql"
	"io/fs"
	"path/filepath"
	"sort"
	"strings"
	"testing"
)

func openTestDB(t *testing.T) *DB {
	t.Helper()
	path := filepath.Join(t.TempDir(), "geniusrun_test.db")
	db, err := Open(path)
	if err != nil {
		t.Fatalf("Open: %v", err)
	}
	t.Cleanup(func() { db.Close() })
	return db
}

func f(v float64) *float64 { return &v }

func TestMigrateIsIdempotent(t *testing.T) {
	path := filepath.Join(t.TempDir(), "geniusrun_test.db")
	db1, err := Open(path)
	if err != nil {
		t.Fatalf("first Open: %v", err)
	}
	db1.Close()

	db2, err := Open(path)
	if err != nil {
		t.Fatalf("second Open (re-applying migrations): %v", err)
	}
	db2.Close()
}

func TestUpsertActivity_InsertThenUpdateIsIdempotent(t *testing.T) {
	db := openTestDB(t)
	ctx := context.Background()
	userID, err := db.ProvisionUser(ctx, "test-sub", "Test")
	if err != nil {
		t.Fatalf("ProvisionUser: %v", err)
	}

	a := Activity{
		GarminActivityID: 23554066504,
		StartTimeUTC:     "2026-07-11 05:02:35",
		DurationSeconds:  1800,
		DistanceMeters:   6858,
		AvgHR:            f(148),
		RawJSON:          `{"activityId":23554066504,"activityName":"Auriol - W2-5-Base Endurance","activityType":{"typeKey":"running"}}`,
	}

	id, err := db.UpsertActivity(ctx, userID, a)
	if err != nil {
		t.Fatalf("UpsertActivity (insert): %v", err)
	}

	a.AvgHR = f(150) // simulate a re-sync with a corrected value
	id2, err := db.UpsertActivity(ctx, userID, a)
	if err != nil {
		t.Fatalf("UpsertActivity (update): %v", err)
	}
	if id != id2 {
		t.Fatalf("expected same internal id across upserts, got %d then %d", id, id2)
	}

	got, ok, err := db.GetActivity(ctx, userID, id)
	if err != nil || !ok {
		t.Fatalf("GetActivity: ok=%v err=%v", ok, err)
	}
	if *got.AvgHR != 150 {
		t.Errorf("AvgHR = %v, want 150 (update should have applied)", *got.AvgHR)
	}

	all, err := db.ListActivities(ctx, userID, ActivityFilter{})
	if err != nil {
		t.Fatalf("ListActivities: %v", err)
	}
	if len(all) != 1 {
		t.Fatalf("expected exactly 1 activity after upsert-update, got %d", len(all))
	}
}

func TestUpsertActivity_SameGarminActivityIDAllowedAcrossDifferentUsers(t *testing.T) {
	db := openTestDB(t)
	ctx := context.Background()
	userA, err := db.ProvisionUser(ctx, "sub-a", "A")
	if err != nil {
		t.Fatalf("ProvisionUser(a): %v", err)
	}
	userB, err := db.ProvisionUser(ctx, "sub-b", "B")
	if err != nil {
		t.Fatalf("ProvisionUser(b): %v", err)
	}

	activity := Activity{GarminActivityID: 999, StartTimeUTC: "2026-07-11 05:00:00", RawJSON: "{}"}
	if _, err := db.UpsertActivity(ctx, userA, activity); err != nil {
		t.Fatalf("UpsertActivity(a): %v", err)
	}
	if _, err := db.UpsertActivity(ctx, userB, activity); err != nil {
		t.Fatalf("expected the same garmin_activity_id to be allowed for a different user, got: %v", err)
	}

	aActivities, err := db.ListActivities(ctx, userA, ActivityFilter{})
	if err != nil || len(aActivities) != 1 {
		t.Fatalf("ListActivities(a): got %d, err=%v", len(aActivities), err)
	}
	bActivities, err := db.ListActivities(ctx, userB, ActivityFilter{})
	if err != nil || len(bActivities) != 1 {
		t.Fatalf("ListActivities(b): got %d, err=%v", len(bActivities), err)
	}
}

func TestKindAssignment_AppendOnlyHistoryAndCurrentView(t *testing.T) {
	db := openTestDB(t)
	ctx := context.Background()
	userID, err := db.ProvisionUser(ctx, "test-sub", "Test")
	if err != nil {
		t.Fatalf("ProvisionUser: %v", err)
	}

	activityID, err := db.UpsertActivity(ctx, userID, Activity{
		GarminActivityID: 1,
		StartTimeUTC:     "2026-07-11 05:00:00",
		RawJSON:          "{}",
	})
	if err != nil {
		t.Fatalf("UpsertActivity: %v", err)
	}

	kindID, err := db.CreateWorkoutKind(ctx, userID, WorkoutKind{
		Name:     "Test Assignment Custom",
		RuleJSON: `{"match":"all","conditions":[]}`,
		IsActive: true,
	})
	if err != nil {
		t.Fatalf("CreateWorkoutKind: %v", err)
	}

	// First: rule engine says needs_review (ambiguous).
	if _, err := db.InsertKindAssignment(ctx, KindAssignment{
		ActivityID:         activityID,
		AssignmentSource:   AssignmentSourceRuleEngine,
		Status:             AssignmentStatusNeedsReview,
		CandidateKindsJSON: `[{"kind_id":1,"score":0.5}]`,
	}); err != nil {
		t.Fatalf("InsertKindAssignment (rule engine): %v", err)
	}

	queue, err := db.ReviewQueue(ctx)
	if err != nil {
		t.Fatalf("ReviewQueue: %v", err)
	}
	if len(queue) != 1 {
		t.Fatalf("expected 1 item in review queue, got %d", len(queue))
	}

	// Then: user manually resolves it.
	if _, err := db.InsertKindAssignment(ctx, KindAssignment{
		ActivityID:       activityID,
		WorkoutKindID:    &kindID,
		AssignmentSource: AssignmentSourceManual,
		Status:           AssignmentStatusAssigned,
	}); err != nil {
		t.Fatalf("InsertKindAssignment (manual): %v", err)
	}

	queue, err = db.ReviewQueue(ctx)
	if err != nil {
		t.Fatalf("ReviewQueue after resolve: %v", err)
	}
	if len(queue) != 0 {
		t.Fatalf("expected 0 items in review queue after manual resolve, got %d", len(queue))
	}

	current, ok, err := db.CurrentAssignment(ctx, activityID)
	if err != nil || !ok {
		t.Fatalf("CurrentAssignment: ok=%v err=%v", ok, err)
	}
	if current.AssignmentSource != AssignmentSourceManual || current.Status != AssignmentStatusAssigned {
		t.Errorf("current assignment = %+v, want manual/assigned", current)
	}

	// The original rule-engine assignment must still exist (append-only history).
	var historyCount int
	if err := db.QueryRowContext(ctx, `SELECT COUNT(*) FROM kind_assignments WHERE activity_id = ?`, activityID).Scan(&historyCount); err != nil {
		t.Fatalf("count history: %v", err)
	}
	if historyCount != 2 {
		t.Errorf("expected 2 historical assignment rows (rule engine + manual), got %d", historyCount)
	}

	forKind, err := db.AssignmentsForKind(ctx, kindID)
	if err != nil {
		t.Fatalf("AssignmentsForKind: %v", err)
	}
	if len(forKind) != 1 {
		t.Fatalf("expected 1 assigned activity for kind %d, got %d", kindID, len(forKind))
	}
}

func TestReplaceLapsIsIdempotent(t *testing.T) {
	db := openTestDB(t)
	ctx := context.Background()
	userID, err := db.ProvisionUser(ctx, "test-sub", "Test")
	if err != nil {
		t.Fatalf("ProvisionUser: %v", err)
	}

	activityID, err := db.UpsertActivity(ctx, userID, Activity{
		GarminActivityID: 2,
		StartTimeUTC:     "2026-07-11 05:00:00",
		RawJSON:          "{}",
	})
	if err != nil {
		t.Fatalf("UpsertActivity: %v", err)
	}

	laps := []Lap{
		{LapIndex: 1, RawJSON: "{}"},
		{LapIndex: 2, RawJSON: "{}"},
	}
	if err := db.ReplaceLaps(ctx, activityID, laps); err != nil {
		t.Fatalf("ReplaceLaps (first): %v", err)
	}
	// Re-sync with a different set (e.g. corrected data) should fully replace, not append.
	if err := db.ReplaceLaps(ctx, activityID, laps[:1]); err != nil {
		t.Fatalf("ReplaceLaps (second): %v", err)
	}

	got, err := db.LapsForActivity(ctx, activityID)
	if err != nil {
		t.Fatalf("LapsForActivity: %v", err)
	}
	if len(got) != 1 {
		t.Fatalf("expected 1 lap after replace, got %d", len(got))
	}
}

func TestUsersAndOwnershipSchema_AppliesCleanly(t *testing.T) {
	db := openTestDB(t)
	ctx := context.Background()

	// A fresh DB has no legacy singleton rows, so every user_id column
	// should already be backfilled to nothing (fresh install, no rows at
	// all yet in these tables besides the migration-seeded workout_kinds --
	// which do have NULL user_id until a real user is provisioned).
	var nullableCount int
	if err := db.QueryRowContext(ctx, `SELECT COUNT(*) FROM workout_kinds WHERE user_id IS NULL`).Scan(&nullableCount); err != nil {
		t.Fatalf("count workout_kinds: %v", err)
	}
	if nullableCount != 8 {
		t.Fatalf("expected 8 migration-seeded workout_kinds with NULL user_id on a fresh DB, got %d", nullableCount)
	}

	// UNIQUE(user_id, name) allows the same name across two different users.
	if _, err := db.ExecContext(ctx, `INSERT INTO users (oidc_sub, display_name) VALUES ('sub-a', 'A'), ('sub-b', 'B')`); err != nil {
		t.Fatalf("insert users: %v", err)
	}
	if _, err := db.ExecContext(ctx, `
		INSERT INTO workout_kinds (user_id, name, rule_json)
		VALUES ((SELECT id FROM users WHERE oidc_sub='sub-a'), 'Custom Kind', '{}'),
		       ((SELECT id FROM users WHERE oidc_sub='sub-b'), 'Custom Kind', '{}')`); err != nil {
		t.Fatalf("expected same workout_kind name to be allowed across two different users, got: %v", err)
	}

	// profile/sync_state UNIQUE(user_id) still rejects a genuine duplicate.
	if _, err := db.ExecContext(ctx, `INSERT INTO profile (user_id) VALUES ((SELECT id FROM users WHERE oidc_sub='sub-a'))`); err != nil {
		t.Fatalf("insert profile for sub-a: %v", err)
	}
	if _, err := db.ExecContext(ctx, `INSERT INTO profile (user_id) VALUES ((SELECT id FROM users WHERE oidc_sub='sub-a'))`); err == nil {
		t.Fatal("expected a second profile row for the same user_id to violate UNIQUE(user_id)")
	}
}

func TestForeignKeyEnforcementPostMigration(t *testing.T) {
	db := openTestDB(t)
	ctx := context.Background()

	// Verify that FK enforcement is correctly active after migrations complete.
	// This tests that the PRAGMA foreign_keys toggle in db.migrate() (for
	// migrations 0023/0024/0025) is properly scoped and re-enabled after each
	// table rebuild.

	userID, err := db.ProvisionUser(ctx, "test-sub", "Test")
	if err != nil {
		t.Fatalf("ProvisionUser: %v", err)
	}

	// Insert an activity that we can reference.
	activityID, err := db.UpsertActivity(ctx, userID, Activity{
		GarminActivityID: 1001,
		StartTimeUTC:     "2026-07-11 05:00:00",
		RawJSON:          "{}",
	})
	if err != nil {
		t.Fatalf("UpsertActivity: %v", err)
	}

	// Get the ID of one of the 8 migration-seeded workout_kinds.
	var seedKindID int64
	if err := db.QueryRowContext(ctx, `SELECT id FROM workout_kinds LIMIT 1`).Scan(&seedKindID); err != nil {
		t.Fatalf("query seeded workout_kind: %v", err)
	}

	// Inserting a kind_assignment with a valid FK reference should succeed.
	assignmentID, err := db.InsertKindAssignment(ctx, KindAssignment{
		ActivityID:       activityID,
		WorkoutKindID:    &seedKindID,
		AssignmentSource: AssignmentSourceManual,
		Status:           AssignmentStatusAssigned,
	})
	if err != nil {
		t.Fatalf("InsertKindAssignment with valid FK: %v", err)
	}
	if assignmentID == 0 {
		t.Fatal("expected non-zero assignment ID")
	}

	// Inserting a kind_assignment with a nonexistent workout_kind_id should
	// be rejected by the FK constraint, proving FK enforcement is ON.
	nonexistentKindID := int64(999999)
	_, err = db.InsertKindAssignment(ctx, KindAssignment{
		ActivityID:       activityID,
		WorkoutKindID:    &nonexistentKindID,
		AssignmentSource: AssignmentSourceManual,
		Status:           AssignmentStatusAssigned,
	})
	if err == nil {
		t.Fatal("expected FK constraint violation for nonexistent workout_kind_id, but insert succeeded")
	}
	// The error message should mention FOREIGN KEY or similar constraint issue.
	if !contains(err.Error(), "FOREIGN KEY", "constraint", "UNIQUE") {
		t.Logf("FK error message: %v", err)
		// Still pass, but log it; the exact error text varies by driver/context.
	}
}

// TestRebuildMigrationsPreserveForeignKeyReferences proves the specific
// property none of the other migration tests cover: every other test opens
// a fresh DB via store.Open, which runs migrations 0001-0025 in one
// uninterrupted pass over an empty database, so migrations 0023/0024/0025's
// table-rebuild (create-new/copy/drop-old/rename-into-place) never has any
// real pre-existing rows to carry across. A real single-tenant deployment
// upgrading to this schema version has months of synced activities and
// kind_assignments rows referencing real workout_kinds rows by foreign key
// (per this repo's CLAUDE.md: one profile, real Garmin history, a review
// queue with manual overrides already recorded). This test manually applies
// migrations up through 0022, inserts rows simulating that pre-existing
// install, then applies 0023/0024/0025 and verifies the FK-referencing row
// still resolves correctly -- and that FK enforcement is genuinely back on
// afterward -- rather than just checking that migrations apply to an empty
// DB without erroring.
func TestRebuildMigrationsPreserveForeignKeyReferences(t *testing.T) {
	ctx := context.Background()
	path := filepath.Join(t.TempDir(), "geniusrun_rebuild_test.db")

	// Deliberately not store.Open: that always applies every migration in
	// one uninterrupted pass with no way to stop partway through. The sqlite
	// driver itself is already registered via db.go's blank import.
	sqlDB, err := sql.Open("sqlite", path+"?_pragma=foreign_keys(1)")
	if err != nil {
		t.Fatalf("open sqlite: %v", err)
	}
	defer sqlDB.Close()

	if _, err := sqlDB.ExecContext(ctx, `CREATE TABLE IF NOT EXISTS schema_migrations (
		filename TEXT PRIMARY KEY,
		applied_at TEXT NOT NULL DEFAULT (datetime('now'))
	)`); err != nil {
		t.Fatalf("create schema_migrations table: %v", err)
	}

	rebuildMigrations := map[string]bool{
		"0023_profile_user_scoped.sql":       true,
		"0024_workout_kinds_user_scoped.sql": true,
		"0025_sync_state_user_scoped.sql":    true,
	}

	// Mirrors db.go's migrate() method: FK toggle in autocommit mode around
	// the transaction, only for the three table-rebuild migrations.
	applyMigration := func(name string) {
		t.Helper()
		content, err := migrationsFS.ReadFile("migrations/" + name)
		if err != nil {
			t.Fatalf("read migration %s: %v", name, err)
		}

		needsFKToggle := rebuildMigrations[name]
		if needsFKToggle {
			if _, err := sqlDB.ExecContext(ctx, `PRAGMA foreign_keys = OFF`); err != nil {
				t.Fatalf("disable foreign keys before migration %s: %v", name, err)
			}
		}

		tx, err := sqlDB.BeginTx(ctx, nil)
		if err != nil {
			t.Fatalf("begin migration tx for %s: %v", name, err)
		}
		if _, err := tx.ExecContext(ctx, string(content)); err != nil {
			tx.Rollback()
			t.Fatalf("apply migration %s: %v", name, err)
		}
		if _, err := tx.ExecContext(ctx, `INSERT INTO schema_migrations (filename) VALUES (?)`, name); err != nil {
			tx.Rollback()
			t.Fatalf("record migration %s: %v", name, err)
		}
		if err := tx.Commit(); err != nil {
			t.Fatalf("commit migration %s: %v", name, err)
		}

		if needsFKToggle {
			if _, err := sqlDB.ExecContext(ctx, `PRAGMA foreign_keys = ON`); err != nil {
				t.Fatalf("enable foreign keys after migration %s: %v", name, err)
			}
		}
	}

	entries, err := fs.Glob(migrationsFS, "migrations/*.sql")
	if err != nil {
		t.Fatalf("glob migrations: %v", err)
	}
	sort.Strings(entries)

	// Apply every migration up to (but not including) the three rebuilds.
	for _, entry := range entries {
		name := entry[len("migrations/"):]
		if rebuildMigrations[name] {
			continue
		}
		applyMigration(name)
	}

	// Simulate a real pre-existing single-tenant install at this point in
	// schema history: a workout kind, a synced activity, and a
	// kind_assignment referencing both by foreign key.
	res, err := sqlDB.ExecContext(ctx, `INSERT INTO workout_kinds (name, rule_json) VALUES ('Pre-Existing Custom Kind', '{}')`)
	if err != nil {
		t.Fatalf("insert pre-existing workout_kinds row: %v", err)
	}
	kindID, err := res.LastInsertId()
	if err != nil {
		t.Fatalf("workout_kinds LastInsertId: %v", err)
	}

	res, err = sqlDB.ExecContext(ctx, `
		INSERT INTO activities (garmin_activity_id, start_time_utc, duration_seconds, distance_meters, raw_json)
		VALUES (123456789, '2026-01-01 06:00:00', 1800, 5000, '{}')`)
	if err != nil {
		t.Fatalf("insert pre-existing activities row: %v", err)
	}
	activityID, err := res.LastInsertId()
	if err != nil {
		t.Fatalf("activities LastInsertId: %v", err)
	}

	res, err = sqlDB.ExecContext(ctx, `
		INSERT INTO kind_assignments (activity_id, workout_kind_id, assignment_source, status)
		VALUES (?, ?, 'rule_engine', 'assigned')`, activityID, kindID)
	if err != nil {
		t.Fatalf("insert pre-existing kind_assignments row: %v", err)
	}
	assignmentID, err := res.LastInsertId()
	if err != nil {
		t.Fatalf("kind_assignments LastInsertId: %v", err)
	}

	// Now apply the three rebuild migrations that drop/recreate profile,
	// workout_kinds, and sync_state.
	for _, name := range []string{
		"0023_profile_user_scoped.sql",
		"0024_workout_kinds_user_scoped.sql",
		"0025_sync_state_user_scoped.sql",
	} {
		applyMigration(name)
	}

	// The pre-existing kind_assignment row must still resolve to the same
	// workout_kind, by the same name, across the drop/recreate/rename.
	var resolvedName string
	if err := sqlDB.QueryRowContext(ctx, `
		SELECT wk.name FROM kind_assignments ka
		JOIN workout_kinds wk ON wk.id = ka.workout_kind_id
		WHERE ka.id = ?`, assignmentID).Scan(&resolvedName); err != nil {
		t.Fatalf("join kind_assignments -> workout_kinds after rebuild: %v", err)
	}
	if resolvedName != "Pre-Existing Custom Kind" {
		t.Fatalf("expected pre-existing kind_assignment to still resolve to 'Pre-Existing Custom Kind' after rebuild, got %q", resolvedName)
	}

	// FK enforcement must be genuinely active again post-migration: a bogus
	// workout_kind_id must be rejected, not silently accepted.
	if _, err := sqlDB.ExecContext(ctx, `
		INSERT INTO kind_assignments (activity_id, workout_kind_id, assignment_source, status)
		VALUES (?, 999999, 'rule_engine', 'assigned')`, activityID); err == nil {
		t.Fatal("expected FK constraint violation for nonexistent workout_kind_id after rebuild, but insert succeeded")
	}
}

func contains(s string, substrs ...string) bool {
	lower := strings.ToLower(s)
	for _, substr := range substrs {
		if strings.Contains(lower, strings.ToLower(substr)) {
			return true
		}
	}
	return false
}