package store

import (
	"context"
	"database/sql"
	"errors"
	"fmt"
	"reflect"
	"testing"
	"time"

	"banger/internal/model"
)

func sampleGuestSession(id, vmID, name string) model.GuestSession {
	now := fixedTime()
	exit := 7
	return model.GuestSession{
		ID:            id,
		VMID:          vmID,
		Name:          name,
		Backend:       "ssh",
		AttachBackend: "vsock",
		AttachMode:    "rpc",
		Command:       "pi",
		Args:          []string{"--mode", "rpc"},
		CWD:           "/root/repo",
		Env:           map[string]string{"FOO": "bar"},
		StdinMode:     model.GuestSessionStdinMode("pipe"),
		Status:        model.GuestSessionStatus("exited"),
		ExitCode:      &exit,
		GuestPID:      1234,
		GuestStateDir: "/tmp/guest-" + id,
		StdoutLogPath: "/tmp/" + id + ".stdout",
		StderrLogPath: "/tmp/" + id + ".stderr",
		Tags:          map[string]string{"role": "planner"},
		LastError:     "",
		Attachable:    true,
		Reattachable:  true,
		LaunchStage:   "started",
		LaunchMessage: "ok",
		LaunchRawLog:  "boot log...",
		CreatedAt:     now,
		StartedAt:     now,
		UpdatedAt:     now,
		EndedAt:       now.Add(time.Minute),
	}
}

// openTestStoreWithVMs opens a fresh store seeded with the given VM IDs so
// guest_sessions FK constraints are satisfied. Each VM gets a minimal
// image it references.
func openTestStoreWithVMs(t *testing.T, vmIDs ...string) *Store {
	t.Helper()
	ctx := context.Background()
	store := openTestStore(t)

	image := sampleImage("stub-image")
	if err := store.UpsertImage(ctx, image); err != nil {
		t.Fatalf("UpsertImage: %v", err)
	}
	for i, id := range vmIDs {
		vm := sampleVM(id, image.ID, fmt.Sprintf("172.16.0.%d", i+2))
		vm.ID = id
		if err := store.UpsertVM(ctx, vm); err != nil {
			t.Fatalf("UpsertVM(%s): %v", id, err)
		}
	}
	return store
}

func TestGuestSessionUpsertAndGetByID(t *testing.T) {
	t.Parallel()
	ctx := context.Background()
	store := openTestStoreWithVMs(t, "vm-1")

	session := sampleGuestSession("sess-1", "vm-1", "planner")
	if err := store.UpsertGuestSession(ctx, session); err != nil {
		t.Fatalf("UpsertGuestSession: %v", err)
	}

	got, err := store.GetGuestSessionByID(ctx, "sess-1")
	if err != nil {
		t.Fatalf("GetGuestSessionByID: %v", err)
	}
	if !reflect.DeepEqual(got, session) {
		t.Fatalf("round-trip mismatch:\n got  %+v\n want %+v", got, session)
	}
}

func TestGuestSessionUpsertIsIdempotent(t *testing.T) {
	t.Parallel()
	ctx := context.Background()
	store := openTestStoreWithVMs(t, "vm-1")

	session := sampleGuestSession("sess-1", "vm-1", "planner")
	if err := store.UpsertGuestSession(ctx, session); err != nil {
		t.Fatalf("UpsertGuestSession (first): %v", err)
	}

	// Mutate + re-upsert → existing row updated.
	session.Command = "pi --other"
	session.Status = model.GuestSessionStatus("running")
	session.ExitCode = nil
	if err := store.UpsertGuestSession(ctx, session); err != nil {
		t.Fatalf("UpsertGuestSession (second): %v", err)
	}

	got, err := store.GetGuestSessionByID(ctx, "sess-1")
	if err != nil {
		t.Fatalf("GetGuestSessionByID: %v", err)
	}
	if got.Command != "pi --other" {
		t.Errorf("command = %q, want 'pi --other'", got.Command)
	}
	if got.Status != model.GuestSessionStatus("running") {
		t.Errorf("status = %q, want running", got.Status)
	}
	if got.ExitCode != nil {
		t.Errorf("ExitCode = %v, want nil after clearing", got.ExitCode)
	}
}

func TestGetGuestSessionByIDOrName(t *testing.T) {
	t.Parallel()
	ctx := context.Background()
	store := openTestStoreWithVMs(t, "vm-1")

	session := sampleGuestSession("sess-1", "vm-1", "planner")
	if err := store.UpsertGuestSession(ctx, session); err != nil {
		t.Fatalf("UpsertGuestSession: %v", err)
	}

	byID, err := store.GetGuestSession(ctx, "vm-1", "sess-1")
	if err != nil {
		t.Fatalf("GetGuestSession by ID: %v", err)
	}
	if byID.ID != "sess-1" {
		t.Errorf("by-ID: got %q, want sess-1", byID.ID)
	}

	byName, err := store.GetGuestSession(ctx, "vm-1", "planner")
	if err != nil {
		t.Fatalf("GetGuestSession by name: %v", err)
	}
	if byName.Name != "planner" {
		t.Errorf("by-name: got %q, want planner", byName.Name)
	}

	// Scoped to the VM.
	if _, err := store.GetGuestSession(ctx, "vm-unknown", "sess-1"); !errors.Is(err, sql.ErrNoRows) {
		t.Errorf("wrong-vm lookup = %v, want sql.ErrNoRows", err)
	}
}

func TestListGuestSessionsByVMOrdersByCreatedAt(t *testing.T) {
	t.Parallel()
	ctx := context.Background()
	store := openTestStoreWithVMs(t, "vm-1", "vm-2")

	base := fixedTime()
	first := sampleGuestSession("sess-early", "vm-1", "first")
	first.CreatedAt = base
	second := sampleGuestSession("sess-late", "vm-1", "second")
	second.CreatedAt = base.Add(time.Hour)
	other := sampleGuestSession("sess-other", "vm-2", "other")

	for _, s := range []model.GuestSession{second, first, other} {
		if err := store.UpsertGuestSession(ctx, s); err != nil {
			t.Fatalf("UpsertGuestSession: %v", err)
		}
	}

	sessions, err := store.ListGuestSessionsByVM(ctx, "vm-1")
	if err != nil {
		t.Fatalf("ListGuestSessionsByVM: %v", err)
	}
	if len(sessions) != 2 {
		t.Fatalf("len = %d, want 2 (vm-1 only)", len(sessions))
	}
	if sessions[0].ID != "sess-early" || sessions[1].ID != "sess-late" {
		t.Fatalf("order: got %q, %q; want sess-early, sess-late", sessions[0].ID, sessions[1].ID)
	}

	empty, err := store.ListGuestSessionsByVM(ctx, "vm-unknown")
	if err != nil {
		t.Fatalf("ListGuestSessionsByVM (unknown vm): %v", err)
	}
	if len(empty) != 0 {
		t.Fatalf("unknown vm sessions = %+v, want empty", empty)
	}
}

func TestDeleteGuestSession(t *testing.T) {
	t.Parallel()
	ctx := context.Background()
	store := openTestStoreWithVMs(t, "vm-1")

	session := sampleGuestSession("sess-1", "vm-1", "planner")
	if err := store.UpsertGuestSession(ctx, session); err != nil {
		t.Fatalf("UpsertGuestSession: %v", err)
	}
	if err := store.DeleteGuestSession(ctx, "sess-1"); err != nil {
		t.Fatalf("DeleteGuestSession: %v", err)
	}
	if _, err := store.GetGuestSessionByID(ctx, "sess-1"); !errors.Is(err, sql.ErrNoRows) {
		t.Fatalf("after delete err = %v, want sql.ErrNoRows", err)
	}

	// Deleting something that doesn't exist is a no-op (matches SQL DELETE semantics).
	if err := store.DeleteGuestSession(ctx, "sess-nope"); err != nil {
		t.Fatalf("DeleteGuestSession on missing row: %v", err)
	}
}