package hostbox

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

	"github.com/carlosframework/platform/internal/genselect"
)

func TestColdRestoreEnrollmentPrecedesEveryMutation(t *testing.T) {
	for _, empty := range []bool{false, true} {
		for _, refuse := range []string{"", "legacy", "enroll"} {
			t.Run(map[bool]string{false: "baseline", true: "empty"}[empty]+"/"+refuse, func(t *testing.T) {
				db := filepath.Join(t.TempDir(), "legacy.db")
				legacy := []byte("legacy database")
				if err := os.WriteFile(db, legacy, 0600); err != nil {
					t.Fatal(err)
				}
				work := &restoreWork{}
				key, body, crc := snapshotFixture(t, "production-restore")
				rd := &restoreReader{data: map[string][]byte{key + "@v1": body}}
				plan := &genselect.Plan{Generation: "baseline", MaxTXID: 1, Pin: &genselect.Pin{SnapshotCRC64: crc}, Files: []genselect.File{{Key: key, VersionID: "v1", Level: 9, MinTXID: 1, MaxTXID: 1, Size: int64(len(body))}}}
				var calls []string
				failure := errors.New("injected enrollment refusal")
				r := ColdRestore{Reader: rd, Bucket: "bucket", Generation: "new", Work: work,
					BeforeLegacyInstall: func(_ context.Context, path, generation string) error {
						if work.active || path != db || generation != "new" {
							t.Fatal("legacy callback boundary")
						}
						calls = append(calls, "legacy")
						if refuse == "legacy" {
							return failure
						}
						if string(mustRead(t, db)) != string(legacy) {
							t.Fatal("legacy source changed before parking")
						}
						// Explicit parking seam; root identity/retention belongs to the host tests.
						return os.Rename(db, db+".parked")
					},
					BeforeInstallLocked: func(_ context.Context, path, generation string) error {
						if !work.active || path != db || generation != "new" {
							t.Fatal("enrollment callback boundary")
						}
						calls = append(calls, "enroll")
						if _, err := os.Stat(db); !errors.Is(err, os.ErrNotExist) {
							t.Fatal("database appeared before enrollment")
						}
						if _, err := os.Stat(db + ".gen"); !errors.Is(err, os.ErrNotExist) {
							t.Fatal("marker appeared before enrollment")
						}
						if refuse == "enroll" {
							return failure
						}
						return nil
					}}
				var err error
				if empty {
					err = r.InstallEmpty(t.Context(), db, func(context.Context) error { return nil })
				} else {
					err = r.Install(t.Context(), db, plan)
				}
				if refuse != "" {
					if !errors.Is(err, failure) {
						t.Fatalf("refusal: %v", err)
					}
					if _, err := os.Stat(db + ".gen"); !errors.Is(err, os.ErrNotExist) {
						t.Fatal("refused enrollment wrote marker")
					}
					if refuse == "legacy" {
						if string(mustRead(t, db)) != string(legacy) {
							t.Fatal("refusal destroyed legacy database")
						}
					} else if string(mustRead(t, db+".parked")) != string(legacy) {
						t.Fatal("refusal destroyed park")
					}
					return
				}
				if err != nil {
					t.Fatal(err)
				}
				if len(calls) != 2 || calls[0] != "legacy" || calls[1] != "enroll" {
					t.Fatalf("callbacks %v", calls)
				}
				if string(mustRead(t, db+".gen")) != "new\n" {
					t.Fatal("missing successor marker")
				}
				if empty {
					if _, err := os.Stat(db); !errors.Is(err, os.ErrNotExist) {
						t.Fatal("empty restore wrote a database")
					}
					return
				}
				check, err := sql.Open("sqlite", db)
				if err != nil {
					t.Fatal(err)
				}
				defer check.Close()
				var value string
				if err := check.QueryRow("SELECT value FROM fixture").Scan(&value); err != nil || value != "production-restore" {
					t.Fatalf("restored %q: %v", value, err)
				}
			})
		}
	}
}