package db

import (
	"database/sql"
	"errors"
	"testing"
	"time"

	"crypto-miner-server/internal/models"
)

func openTestDB(t *testing.T) *Database {
	t.Helper()
	d, err := New(t.TempDir())
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { d.Close() })
	return d
}

func seedAgent(t *testing.T, d *Database, id string) *models.Agent {
	t.Helper()
	a := &models.Agent{
		ID:       id,
		Name:     "worker-" + id,
		Hostname: "worker-" + id,
		Wallet:   "wallet",
		IP:       "10.0.0.1",
		Version:  "2.0",
		Status:   "offline",
		CPUCores: 4,
		MemoryGB: 8,
		LastSeen: time.Now(),
	}
	if err := d.UpsertAgent(a); err != nil {
		t.Fatal(err)
	}
	return a
}

func TestNewCreatesDatabase(t *testing.T) {
	dir := t.TempDir()
	d, err := New(dir)
	if err != nil {
		t.Fatal(err)
	}
	defer d.Close()

	var n int
	if err := d.QueryRow("SELECT COUNT(*) FROM sqlite_master WHERE type='table' AND name='agents'").Scan(&n); err != nil {
		t.Fatal(err)
	}
	if n != 1 {
		t.Fatalf("expected agents table, got count %d", n)
	}
}

func TestGetAgentNotFound(t *testing.T) {
	d := openTestDB(t)
	_, err := d.GetAgent("missing-agent")
	if !errors.Is(err, sql.ErrNoRows) {
		t.Fatalf("expected sql.ErrNoRows, got %v", err)
	}
}

func TestUpsertAgentPreservesOperatorNameWhenDiffersFromHostname(t *testing.T) {
	d := openTestDB(t)
	a := &models.Agent{
		ID:       "renamed-worker",
		Name:     "Living Room PC",
		Hostname: "DESKTOP-ABC123",
		Status:   "offline",
		LastSeen: time.Now(),
	}
	if err := d.UpsertAgent(a); err != nil {
		t.Fatal(err)
	}

	// Reconnect reports hostname only — UpsertAgent must keep operator label.
	a.Name = "DESKTOP-ABC123"
	a.Hostname = "DESKTOP-ABC123"
	a.Status = "online"
	if err := d.UpsertAgent(a); err != nil {
		t.Fatal(err)
	}

	got, err := d.GetAgent(a.ID)
	if err != nil {
		t.Fatal(err)
	}
	if got.Name != "Living Room PC" {
		t.Fatalf("operator name should be preserved; got %q hostname=%q", got.Name, got.Hostname)
	}
}

func TestUpsertAgentPreservesCreatedAt(t *testing.T) {
	d := openTestDB(t)
	a := seedAgent(t, d, "persist-created")

	first, err := d.GetAgent(a.ID)
	if err != nil {
		t.Fatal(err)
	}

	time.Sleep(10 * time.Millisecond)
	a.Name = "renamed"
	if a.Hostname == "" {
		a.Hostname = first.Name
	}
	a.Hostname = "renamed"
	a.Status = "online"
	if err := d.UpsertAgent(a); err != nil {
		t.Fatal(err)
	}

	second, err := d.GetAgent(a.ID)
	if err != nil {
		t.Fatal(err)
	}
	if !second.CreatedAt.Equal(first.CreatedAt) {
		t.Fatalf("created_at changed: %v -> %v", first.CreatedAt, second.CreatedAt)
	}
	if second.Name != "renamed" {
		t.Fatalf("name not updated: %q", second.Name)
	}
}

func TestUpdateAgentStats(t *testing.T) {
	d := openTestDB(t)
	a := seedAgent(t, d, "stats-agent")

	if err := d.UpdateAgentStats(a.ID, 100, 200, 300, 10, 8, 2, 55.5, 66.6, 3600); err != nil {
		t.Fatal(err)
	}

	got, err := d.GetAgent(a.ID)
	if err != nil {
		t.Fatal(err)
	}
	if got.Status != "online" {
		t.Fatalf("status: got %q want online", got.Status)
	}
	if got.Hashrate15s != 100 || got.Hashrate1m != 200 || got.Hashrate15m != 300 {
		t.Fatalf("hashrate mismatch: %+v", got)
	}
	if got.SharesTotal != 10 || got.SharesGood != 8 || got.SharesBad != 2 {
		t.Fatalf("shares mismatch: %+v", got)
	}
	if got.CPUUsagePct != 55.5 || got.MemoryUsagePct != 66.6 || got.UptimeSeconds != 3600 {
		t.Fatalf("usage/uptime mismatch: %+v", got)
	}
}

func TestSetAgentOffline(t *testing.T) {
	d := openTestDB(t)
	a := seedAgent(t, d, "offline-agent")
	if err := d.UpdateAgentStats(a.ID, 1, 1, 1, 0, 0, 0, 0, 0, 0); err != nil {
		t.Fatal(err)
	}

	if err := d.SetAgentOffline(a.ID); err != nil {
		t.Fatal(err)
	}
	got, err := d.GetAgent(a.ID)
	if err != nil {
		t.Fatal(err)
	}
	if got.Status != "offline" {
		t.Fatalf("status: got %q want offline", got.Status)
	}
}

func TestShareInsertUpdateAndRecent(t *testing.T) {
	d := openTestDB(t)
	seedAgent(t, d, "share-agent")

	ts := time.Now().UTC().Truncate(time.Second)
	share := &models.Share{
		AgentID:    "share-agent",
		JobID:      "job-1",
		Difficulty: 1000,
		Accepted:   false,
		Hash:       "abc123",
		Nonce:      "deadbeef",
		Error:      "pending",
		Timestamp:  ts,
	}
	id, err := d.InsertShare(share)
	if err != nil {
		t.Fatal(err)
	}
	if id <= 0 {
		t.Fatalf("expected positive insert id, got %d", id)
	}

	if err := d.UpdateShareResult(id, true, ""); err != nil {
		t.Fatal(err)
	}

	recent, err := d.GetRecentShares(10)
	if err != nil {
		t.Fatal(err)
	}
	if len(recent) != 1 {
		t.Fatalf("expected 1 share, got %d", len(recent))
	}
	if !recent[0].Accepted {
		t.Fatal("share should be accepted after update")
	}
	if recent[0].Error != "" {
		t.Fatalf("error should be cleared, got %q", recent[0].Error)
	}

	if err := d.UpdateShareResult(id, false, "pool rejected"); err != nil {
		t.Fatal(err)
	}
	recent, err = d.GetRecentShares(1)
	if err != nil {
		t.Fatal(err)
	}
	if recent[0].Accepted || recent[0].Error != "pool rejected" {
		t.Fatalf("unexpected share after reject update: %+v", recent[0])
	}
}

func TestHashrateSampleHistory(t *testing.T) {
	d := openTestDB(t)
	seedAgent(t, d, "hr-agent")

	if err := d.InsertHashrateSample("hr-agent", 150.5, 0); err != nil {
		t.Fatal(err)
	}
	if err := d.InsertHashrateSample("hr-agent", 200.0, 10.0); err != nil {
		t.Fatal(err)
	}

	history, err := d.GetHashrateHistory("hr-agent", 5)
	if err != nil {
		t.Fatal(err)
	}
	if len(history) != 2 {
		t.Fatalf("expected 2 samples, got %d", len(history))
	}
	if history[0].Hashrate != 200.0 {
		t.Fatalf("expected newest first, got %f", history[0].Hashrate)
	}

	empty, err := d.GetHashrateHistory("unknown", 5)
	if err != nil {
		t.Fatal(err)
	}
	if len(empty) != 0 {
		t.Fatalf("expected empty history, got %d", len(empty))
	}
}

func TestGetFleetStatsWithAgents(t *testing.T) {
	d := openTestDB(t)
	seedAgent(t, d, "fleet-a")
	seedAgent(t, d, "fleet-b")

	if err := d.UpdateAgentStats("fleet-a", 0, 0, 100, 20, 18, 2, 0, 0, 0); err != nil {
		t.Fatal(err)
	}
	if err := d.UpdateAgentStats("fleet-b", 0, 0, 50, 10, 5, 5, 0, 0, 0); err != nil {
		t.Fatal(err)
	}

	stats, err := d.GetFleetStats()
	if err != nil {
		t.Fatal(err)
	}
	if stats.TotalAgents != 2 {
		t.Fatalf("total agents: got %d want 2", stats.TotalAgents)
	}
	if stats.OnlineAgents != 2 {
		t.Fatalf("online agents: got %d want 2", stats.OnlineAgents)
	}
	if stats.TotalHashrate != 150 {
		t.Fatalf("total hashrate: got %f want 150", stats.TotalHashrate)
	}
	if stats.TotalShares != 30 || stats.AcceptedShares != 23 || stats.RejectedShares != 7 {
		t.Fatalf("share totals mismatch: %+v", stats)
	}
	wantRate := float64(23) / float64(30) * 100
	if stats.AcceptRate != wantRate {
		t.Fatalf("accept rate: got %f want %f", stats.AcceptRate, wantRate)
	}
}