package dbquery

import (
	"bytes"
	"context"
	"database/sql"
	"errors"
	"path/filepath"
	"strings"
	"testing"

	_ "modernc.org/sqlite"
)

func fixtureDB(t *testing.T) string {
	t.Helper()
	path := filepath.Join(t.TempDir(), "shop.db")
	db, err := sql.Open("sqlite", path)
	if err != nil {
		t.Fatal(err)
	}
	defer db.Close()
	for _, q := range []string{
		`CREATE TABLE orders (id INTEGER PRIMARY KEY, note TEXT, data BLOB)`,
		`INSERT INTO orders (note, data) VALUES ('a	tab', x'00ff'), (NULL, NULL), ('two
lines', 'x')`,
	} {
		if _, err := db.Exec(q); err != nil {
			t.Fatal(err)
		}
	}
	return path
}

func TestRunContextFormatsLikeTheCLI(t *testing.T) {
	t.Parallel()
	path := fixtureDB(t)
	for _, opt := range []Options{{}, {Immutable: true}} {
		var out bytes.Buffer
		if err := RunContext(context.Background(), &out, path, "SELECT id, note FROM orders ORDER BY id", opt); err != nil {
			t.Fatalf("%+v: %v", opt, err)
		}
		want := "id\tnote\n1\ta\\ttab\n2\tNULL\n3\ttwo\\nlines\n"
		if out.String() != want {
			t.Fatalf("%+v: got %q, want %q", opt, out.String(), want)
		}
	}
}

func TestRunContextRefusesWritesAndAttach(t *testing.T) {
	t.Parallel()
	path := fixtureDB(t)
	for _, opt := range []Options{{}, {Immutable: true}} {
		for _, q := range []string{
			"DELETE FROM orders",
			"ATTACH DATABASE 'x.db' AS x",
			"VACUUM INTO 'copy.db'",
		} {
			if err := RunContext(context.Background(), &bytes.Buffer{}, path, q, opt); err == nil {
				t.Fatalf("%+v: %q ran", opt, q)
			}
		}
	}
}

func TestCheckSQLTable(t *testing.T) {
	t.Parallel()
	for _, c := range []struct {
		q    string
		want error
	}{
		{"SELECT 1", nil},
		{"SELECT 1; SELECT 2", ErrOneStatement},
		{"SELECT ';' AS x", nil},
		{"PRAGMA table_info(orders)", nil},
		{"PRAGMA query_only = 0", ErrPragmaChange},
		{"EXPLAIN QUERY PLAN PRAGMA writable_schema=1", ErrPragmaChange},
		{"SELECT pragma FROM t", nil},
	} {
		if got := CheckSQL(c.q); !errors.Is(got, c.want) && !(got == nil && c.want == nil) {
			t.Errorf("CheckSQL(%q) = %v, want %v", c.q, got, c.want)
		}
	}
}

func TestImmutableOpenAddsTheFlagOnly(t *testing.T) {
	t.Parallel()
	if got := dsn("/x/copy.db", Options{}); strings.Contains(got, "immutable") {
		t.Fatalf("the CLI's open changed: %s", got)
	}
	if got := dsn("/x/copy.db", Options{Immutable: true}); !strings.Contains(got, "mode=ro&immutable=1&") {
		t.Fatalf("the worker's open lacks immutable=1: %s", got)
	}
}