package errors

import (
	"errors"
	"fmt"
	"net/http"
	"testing"

	code2 "code.30cm.net/digimon/library-go/errors/code"

	"github.com/stretchr/testify/assert"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"
)

func TestCode_GivenNilReceiver_CodeReturnOK_CodeStrReturns00000(t *testing.T) {
	// setup
	var e *LibError = nil

	// act & assert
	assert.Equal(t, code2.OK, e.Code())
	assert.Equal(t, "00000", e.CodeStr())
	assert.Equal(t, "", e.Error())
}

func TestCode_GivenScope99DetailCode6687_ShouldReturn996687(t *testing.T) {
	// setup
	e := LibError{scope: 99, code: 6687}

	// act & assert
	assert.Equal(t, uint32(6687), e.Code())
	assert.Equal(t, "996687", e.CodeStr())
}

func TestCode_GivenScope0DetailCode87_ShouldReturn87(t *testing.T) {
	// setup
	e := LibError{scope: 0, code: 87}

	// act & assert
	assert.Equal(t, uint32(87), e.Code())
	assert.Equal(t, "00087", e.CodeStr())
}

func TestFromCode_Given870005_ShouldHasScope87_Cat0_Detail5(t *testing.T) {
	// setup
	e := FromCode(870005)

	// assert
	assert.Equal(t, uint32(87), e.Scope())
	assert.Equal(t, uint32(0), e.Category())
	assert.Equal(t, uint32(5), e.Code())
	assert.Equal(t, "", e.Error())
}

func TestFromCode_Given0_ShouldHasScope0_Cat0_Detail0(t *testing.T) {
	// setup
	e := FromCode(0)

	// assert
	assert.Equal(t, uint32(0), e.Scope())
	assert.Equal(t, uint32(0), e.Category())
	assert.Equal(t, uint32(0), e.Code())
	assert.Equal(t, "", e.Error())
}

func TestFromCode_Given9105_ShouldHasScope0_Cat9100_Detail9105(t *testing.T) {
	// setup
	e := FromCode(9105)

	// assert
	assert.Equal(t, uint32(0), e.Scope())
	assert.Equal(t, uint32(9100), e.Category())
	assert.Equal(t, uint32(9105), e.Code())
	assert.Equal(t, "", e.Error())
}

func TestErr_ShouldImplementErrorFunction(t *testing.T) {
	// setup a func return error
	f := func() error { return InvalidFormat("fake field") }

	// act
	err := f()

	// assert
	assert.NotNil(t, err)
	assert.Contains(t, fmt.Sprint(err), "fake field") // can be printed
}

func TestGeneralError_GivenNilErr_ShouldReturnEmptyString(t *testing.T) {
	// setup
	var e *LibError = nil

	// act & assert
	assert.Equal(t, "", e.GeneralError())
}

func TestGeneralError_GivenNotExistCat_ShouldReturnEmptyString(t *testing.T) {
	// setup
	e := LibError{category: 123456}

	// act & assert
	assert.Equal(t, "", e.GeneralError())
}

func TestGeneralError_GivenCatDB_ShouldReturnDBError(t *testing.T) {
	// setup
	e := LibError{category: code2.CatDB}
	catErrStr := code2.CatToStr[code2.CatDB]

	// act & assert
	assert.Equal(t, catErrStr, e.GeneralError())
}

func TestError_GivenEmptyMsg_ShouldReturnCatGeneralErrorMessage(t *testing.T) {
	// setup
	e := LibError{category: code2.CatDB, msg: ""}

	// act
	errMsg := e.Error()

	// assert
	assert.Equal(t, code2.CatToStr[code2.CatDB], errMsg)
}

func TestError_GivenMsg_ShouldReturnGiveMsg(t *testing.T) {
	// setup
	e := LibError{msg: "FAKE"}

	// act
	errMsg := e.Error()

	// assert
	assert.Equal(t, "FAKE", errMsg)
}

func TestIs_GivenNilErr_ShouldReturnFalse(t *testing.T) {
	var nilErrs *LibError
	// act
	result := errors.Is(nilErrs, DBError())
	result2 := errors.Is(DBError(), nilErrs)

	// assert
	assert.False(t, result)
	assert.False(t, result2)
}

func TestIs_GivenNil_ShouldReturnFalse(t *testing.T) {
	// act
	result := errors.Is(nil, DBError())
	result2 := errors.Is(DBError(), nil)

	// assert
	assert.False(t, result)
	assert.False(t, result2)
}

func TestIs_GivenNilReceiver_ShouldReturnCorrectResult(t *testing.T) {
	var nilErr *LibError = nil

	// test 1: nilErr != DBError
	var dbErr error = DBError("fake db error")
	assert.False(t, nilErr.Is(dbErr))

	// test 2: nilErr != nil error
	var nilError error
	assert.False(t, nilErr.Is(nilError))

	// test 3: nilErr == another nilErr
	var nilErr2 *LibError = nil
	assert.True(t, nilErr.Is(nilErr2))
}

func TestIs_GivenDBError_ShouldReturnTrue(t *testing.T) {
	// setup
	dbErr := DBError("fake db error")

	// act
	result := errors.Is(dbErr, DBError("not care"))
	result2 := errors.Is(DBError(), dbErr)

	// assert
	assert.True(t, result)
	assert.True(t, result2)
}

func TestIs_GivenDBErrorAssignToErrorType_ShouldReturnTrue(t *testing.T) {
	// setup
	var dbErr error = DBError("fake db error")

	// act
	result := errors.Is(dbErr, DBError("not care"))
	result2 := errors.Is(DBError(), dbErr)

	// assert
	assert.True(t, result)
	assert.True(t, result2)
}

func TestWrap_GivenNilErr_ShouldNoPanic(t *testing.T) {
	// act & assert
	assert.NotPanics(t, func() {
		var e *LibError = nil
		_ = e.Wrap(fmt.Errorf("test"))
	})
}

func TestWrap_GivenErrorToWrap_ShouldReturnErrorWithWrappedError(t *testing.T) {
	// act & assert
	wrappedErr := fmt.Errorf("test")
	wrappingErr := SystemInternalError("WrappingError").Wrap(wrappedErr)
	unWrappedErr := wrappingErr.Unwrap()

	assert.Equal(t, wrappedErr, unWrappedErr)
}

func TestUnwrap_GivenNilErr_ShouldReturnNil(t *testing.T) {
	var e *LibError = nil
	internalErr := e.Unwrap()
	assert.Nil(t, internalErr)
}

func TestErrorsIs_GivenNilErr_ShouldReturnFalse(t *testing.T) {
	var e *LibError = nil
	assert.False(t, errors.Is(e, fmt.Errorf("test")))
}

func TestErrorsAs_GivenNilErr_ShouldReturnFalse(t *testing.T) {
	var internalErr *testErr
	var e *LibError = nil
	assert.False(t, errors.As(e, &internalErr))
}

func TestGRPCStatus(t *testing.T) {
	// setup table driven tests
	tests := []struct {
		name          string
		given         *LibError
		expect        *status.Status
		expectConvert error
	}{
		{
			"nil errs.Err",
			nil,
			status.New(codes.OK, ""),
			nil,
		},
		{
			"InvalidFormat Err",
			InvalidFormat("fake"),
			status.New(codes.Code(101), "invalid format: fake"),
			status.New(codes.Code(101), "invalid format: fake").Err(),
		},
	}

	// act & assert
	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			s := test.given.GRPCStatus()
			assert.Equal(t, test.expect.Code(), s.Code())
			assert.Equal(t, test.expect.Message(), s.Message())
			assert.Equal(t, test.expectConvert, status.Convert(test.given).Err())
		})
	}
}

func TestErr_HTTPStatus(t *testing.T) {
	tests := []struct {
		name string
		err  *LibError
		want int
	}{
		{name: "nil error", err: nil, want: http.StatusOK},
		{name: "invalid measurement id", err: &LibError{category: code2.CatResource, code: code2.InvalidMeasurementID}, want: http.StatusInternalServerError},
		{name: "resource already exists", err: &LibError{category: code2.CatResource, code: code2.ResourceAlreadyExist}, want: http.StatusConflict},
		{name: "invalid resource state", err: &LibError{category: code2.CatResource, code: code2.InvalidResourceState}, want: http.StatusConflict},
		{name: "invalid posix time", err: &LibError{category: code2.CatAuth, code: code2.InvalidPosixTime}, want: http.StatusForbidden},
		{name: "unauthorized", err: &LibError{category: code2.CatAuth, code: code2.Unauthorized}, want: http.StatusUnauthorized},
		{name: "db error", err: &LibError{category: code2.CatDB, code: code2.DBError}, want: http.StatusInternalServerError},
		{name: "insufficient permission", err: &LibError{category: code2.CatResource, code: code2.InsufficientPermission}, want: http.StatusUnauthorized},
		{name: "resource insufficient", err: &LibError{category: code2.CatResource, code: code2.ResourceInsufficient}, want: http.StatusBadRequest},
		{name: "invalid format", err: &LibError{category: code2.CatInput, code: code2.InvalidFormat}, want: http.StatusBadRequest},
		{name: "resource not found", err: &LibError{code: code2.ResourceNotFound}, want: http.StatusNotFound},
		{name: "ok", err: &LibError{code: code2.OK}, want: http.StatusOK},
		{name: "not valid implementation", err: &LibError{category: code2.CatInput, code: code2.NotValidImplementation}, want: http.StatusNotImplemented},
		{name: "forbidden", err: &LibError{category: code2.CatAuth, code: code2.Forbidden}, want: http.StatusForbidden},
		{name: "insufficient quota", err: &LibError{category: code2.CatResource, code: code2.InsufficientQuota}, want: http.StatusPaymentRequired},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {

			// act
			got := tt.err.HTTPStatus()

			// assert
			assert.Equal(t, tt.want, got)
		})
	}
}