package audit_test

import (
	"context"
	"database/sql"
	"path/filepath"
	"testing"

	"git.lohmar.co.uk/cclohmar/NextMyDay/internal/core/audit"
	"git.lohmar.co.uk/cclohmar/NextMyDay/internal/core/store"
)

func newDB(t *testing.T) *sql.DB {
	t.Helper()
	db, err := store.Open(filepath.Join(t.TempDir(), "test.db"))
	if err != nil {
		t.Fatalf("store.Open: %v", err)
	}
	t.Cleanup(func() { _ = db.Close() })
	if err := db.Migrate(); err != nil {
		t.Fatalf("Migrate: %v", err)
	}
	return db.DB
}

func TestRecordWritesRow(t *testing.T) {
	db := newDB(t)
	log := audit.New(db)

	log.Record(context.Background(), audit.Event{
		ActorUserID:   7,
		Action:        "login",
		Subject:       "identity:3",
		Detail:        "totp",
		ClientIP:      "203.0.113.9",
		Location:      "GB",
		CorrelationID: "corr-1",
	})

	var (
		actor   sql.NullInt64
		action  string
		subject string
		detail  string
		ip      string
		loc     string
		corr    string
	)
	err := db.QueryRow(
		`SELECT actor_user_id, action, subject, detail, client_ip, location, correlation_id FROM audit_log`,
	).Scan(&actor, &action, &subject, &detail, &ip, &loc, &corr)
	if err != nil {
		t.Fatalf("query audit_log: %v", err)
	}
	if !actor.Valid || actor.Int64 != 7 {
		t.Errorf("actor_user_id = %+v, want 7", actor)
	}
	if action != "login" || subject != "identity:3" || detail != "totp" {
		t.Errorf("row = (%s,%s,%s)", action, subject, detail)
	}
	if ip != "203.0.113.9" || loc != "GB" || corr != "corr-1" {
		t.Errorf("context = (%s,%s,%s)", ip, loc, corr)
	}
}

func TestRecordAnonymousActorIsNull(t *testing.T) {
	db := newDB(t)
	log := audit.New(db)

	log.Record(context.Background(), audit.Event{Action: "bootstrap"})

	var actor sql.NullInt64
	if err := db.QueryRow(`SELECT actor_user_id FROM audit_log`).Scan(&actor); err != nil {
		t.Fatalf("query: %v", err)
	}
	if actor.Valid {
		t.Errorf("actor_user_id = %d, want NULL for an anonymous event", actor.Int64)
	}
}

// TestMetaRoundTrip pins the R-1 context seam: WithMeta/MetaFrom are lossless.
func TestMetaRoundTrip(t *testing.T) {
	ctx := context.Background()
	if _, ok := audit.MetaFrom(ctx); ok {
		t.Fatal("MetaFrom(background) reported a meta, want none")
	}

	want := audit.Meta{ActorUserID: 42, ClientIP: "203.0.113.5", CorrelationID: "corr-9"}
	got, ok := audit.MetaFrom(audit.WithMeta(ctx, want))
	if !ok {
		t.Fatal("MetaFrom(withMeta) reported none")
	}
	if got != want {
		t.Errorf("MetaFrom = %+v, want %+v", got, want)
	}
}

// TestRecordMergesContextMeta proves the door's Meta reaches the audit row
// without the service threading it by hand (R-1); explicit event values win.
func TestRecordMergesContextMeta(t *testing.T) {
	db := newDB(t)
	log := audit.New(db)

	ctx := audit.WithMeta(context.Background(), audit.Meta{
		ActorUserID:   55,
		ClientIP:      "198.51.100.7",
		CorrelationID: "corr-abc",
	})

	// The event carries no context fields — all come from the Meta.
	log.Record(ctx, audit.Event{Action: "login"})

	// This event overrides the actor explicitly — the event value must win.
	log.Record(ctx, audit.Event{Action: "identity.revoke", ActorUserID: 9})

	rows, err := db.Query(`SELECT action, actor_user_id, client_ip, correlation_id FROM audit_log ORDER BY id`)
	if err != nil {
		t.Fatalf("query audit_log: %v", err)
	}
	defer rows.Close()

	type row struct {
		action string
		actor  sql.NullInt64
		ip     sql.NullString
		corr   sql.NullString
	}
	var got []row
	for rows.Next() {
		var r row
		if err := rows.Scan(&r.action, &r.actor, &r.ip, &r.corr); err != nil {
			t.Fatalf("scan: %v", err)
		}
		got = append(got, r)
	}
	if err := rows.Err(); err != nil {
		t.Fatalf("rows: %v", err)
	}
	if len(got) != 2 {
		t.Fatalf("got %d rows, want 2", len(got))
	}

	if !got[0].actor.Valid || got[0].actor.Int64 != 55 {
		t.Errorf("row 0 actor = %+v, want 55 (from Meta)", got[0].actor)
	}
	if got[0].ip.String != "198.51.100.7" || got[0].corr.String != "corr-abc" {
		t.Errorf("row 0 context = (%q,%q), want the Meta values", got[0].ip.String, got[0].corr.String)
	}
	if !got[1].actor.Valid || got[1].actor.Int64 != 9 {
		t.Errorf("row 1 actor = %+v, want 9 (explicit event value wins)", got[1].actor)
	}
	if got[1].corr.String != "corr-abc" {
		t.Errorf("row 1 correlation = %q, want corr-abc", got[1].corr.String)
	}
}