package ph7_test

import (
	"bytes"
	"errors"
	"fmt"
	"testing"

	ph7 "git.codemonkeysoftware.net/b/go-ph7"
)

func mustSucceed(t *testing.T, err error) {
	t.Helper()
	if err != nil {
		t.Fatal(err.Error())
	}
}

func mustFail(t *testing.T, err error) {
	t.Helper()
	if err == nil {
		t.Fatal("expected error, got nil")
	}
}

func mustSucceedF(t *testing.T, f func() error) {
	t.Helper()
	err := f()
	if err != nil {
		t.Fatal(err.Error())
	}
}

func TestCore(t *testing.T) {
	engine, err := ph7.NewEngine()
	mustSucceed(t, err)
	defer mustSucceedF(t, engine.Close)

	vm, err := engine.Compile([]byte("<?php echo 'Hello world!'; ?>"), false)
	mustSucceed(t, err)
	defer mustSucceedF(t, vm.Close)

	mustSucceed(t, vm.Exec())
	output, err := vm.ExtractOutput()
	mustSucceed(t, err)
	if output != "Hello world!" {
		t.Fatalf("unexpected output: %s", output)
	}

	mustSucceed(t, vm.Reset())

	mustSucceed(t, vm.Exec())
	output, err = vm.ExtractOutput()
	mustSucceed(t, err)
	if output != "Hello world!" {
		t.Fatalf("unexpected output: %s", output)
	}
}

func TestCompileError(t *testing.T) {
	engine, err := ph7.NewEngine()
	mustSucceed(t, err)
	defer mustSucceedF(t, engine.Close)

	_, err = engine.Compile([]byte("<?php 1234 echo 'Hello world!'; ?>"), false)
	mustFail(t, err)
	var target ph7.CompileError
	isCompileError := errors.As(err, &target)
	if !isCompileError || target.Msg == "" {
		t.Fatalf("expected compile error, got %#v", err)
	}
}

func TestOutputWriter(t *testing.T) {
	const source = `<?php
		for ($x = 0; $x <= 1000; $x++) {
			echo $x;
		}
		?>`
	var expected bytes.Buffer
	for i := 0; i <= 1000; i++ {
		_, err := fmt.Fprint(&expected, i)
		mustSucceed(t, err)
	}

	engine, err := ph7.NewEngine()
	mustSucceed(t, err)
	defer mustSucceedF(t, engine.Close)

	vm, err := engine.Compile([]byte(source), false)
	mustSucceed(t, err)
	defer vm.Close()

	var actual bytes.Buffer
	err = vm.SetOutputWriter(&actual)
	mustSucceed(t, err)

	mustSucceed(t, vm.Exec())

	if !bytes.Equal(expected.Bytes(), actual.Bytes()) {
		t.Fatalf("expected %s, got %s", expected.String(), actual.String())
	}
}

// TODO Test failing writer, including vm.OutputWriteError
// TODO Test setting writer twice