package migrations

import (
	"bytes"
	"context"
	"crypto/sha256"
	"encoding/hex"
	"os"
	"path/filepath"
	"strings"
	"testing"
	"testing/fstest"
)

func TestEmbeddedBundleMatchesCanonicalSQL(t *testing.T) {
	all, err := discover(sqlFiles)
	if err != nil {
		t.Fatal(err)
	}
	canonical, err := filepath.Glob("../../../database/migrations/*.sql")
	if err != nil {
		t.Fatal(err)
	}
	if len(canonical) != len(all) {
		t.Fatalf("canonical count %d differs from embedded count %d", len(canonical), len(all))
	}
	for i, path := range canonical {
		data, err := os.ReadFile(path)
		if err != nil {
			t.Fatal(err)
		}
		version := strings.TrimSuffix(filepath.Base(path), ".sql")
		if all[i].version != version || !bytes.Equal(data, []byte(all[i].sql)) {
			t.Fatalf("embedded migration %s differs from canonical SQL", version)
		}
		checksum := sha256.Sum256(data)
		if all[i].checksum != hex.EncodeToString(checksum[:]) {
			t.Fatalf("checksum differs for %s", version)
		}
	}
}

func TestDiscoverMigrations(t *testing.T) {
	fsys := fstest.MapFS{
		"sql/0002.sql": {Data: []byte("select 2;\n")},
		"sql/0001.sql": {Data: []byte("select 1;\n")},
	}
	all, err := discover(fsys)
	if err != nil || len(all) != 2 || all[0].version != "0001" || all[1].version != "0002" {
		t.Fatalf("discover: %+v, %v", all, err)
	}
}

func TestOuterTransactionRemoval(t *testing.T) {
	for _, tc := range []struct {
		in, want string
	}{
		{"-- title\n\nBEGIN;\nselect 1;\nCOMMIT;\n", "-- title\n\nselect 1;\n"},
		{"do $$ begin raise notice 'x'; end $$;", "do $$ begin raise notice 'x'; end $$;"},
	} {
		got, err := withoutOuterTransaction(tc.in)
		if err != nil || got != tc.want {
			t.Fatalf("got %q, %v; want %q", got, err, tc.want)
		}
	}
	for _, sql := range []string{"begin;\nselect 1;", "select 1;\ncommit;"} {
		if _, err := withoutOuterTransaction(sql); err == nil {
			t.Fatalf("accepted unmatched transaction: %q", sql)
		}
	}
}

func TestRunDisabledAndConfiguration(t *testing.T) {
	getter := func(mapper map[string]string) func(string) string {
		return func(key string) string { return mapper[key] }
	}
	if err := Run(context.Background(), getter(nil)); err != nil {
		t.Fatal(err)
	}
	for _, tc := range []struct {
		env  map[string]string
		want string
	}{
		{map[string]string{"DATABASE_AUTO_MIGRATE": "yes"}, "must be true or false"},
		{map[string]string{"DATABASE_AUTO_MIGRATE": "true", "ZHINIAN_DATA_BACKEND": "local"}, "requires ZHINIAN_DATA_BACKEND=postgres"},
		{map[string]string{"DATABASE_AUTO_MIGRATE": "true", "ZHINIAN_DATA_BACKEND": "postgres", "DATABASE_MIGRATION_TIMEOUT_SECONDS": "0"}, "must be an integer"},
		{map[string]string{"DATABASE_AUTO_MIGRATE": "true", "ZHINIAN_DATA_BACKEND": "postgres", "NODE_ENV": "production"}, "DATABASE_APP_ROLE is required"},
		{map[string]string{"DATABASE_AUTO_MIGRATE": "true", "ZHINIAN_DATA_BACKEND": "postgres"}, "DATABASE_MIGRATION_URL or DATABASE_URL is required"},
		{map[string]string{"DATABASE_AUTO_MIGRATE": "true", "ZHINIAN_DATA_BACKEND": "postgres", "DATABASE_APP_ROLE": "bad;role"}, "DATABASE_APP_ROLE must match"},
		{map[string]string{"DATABASE_AUTO_MIGRATE": "true", "ZHINIAN_DATA_BACKEND": "postgres", "DATABASE_MIGRATION_URL": "postgres://admin:secret@localhost/db1", "DATABASE_URL": "postgres://app:secret@localhost/db2"}, "must target the same"},
	} {
		err := Run(context.Background(), getter(tc.env))
		if err == nil || !strings.Contains(err.Error(), tc.want) {
			t.Fatalf("env %+v: got %v, want %q", tc.env, err, tc.want)
		}
	}
}