// Copyright Sam Xie
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package otelsql

import (
	"database/sql/driver"
	"errors"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"go.opentelemetry.io/otel/attribute"
)

type mockTx struct {
	shouldError bool

	commitCount   int
	rollbackCount int
}

func newMockTx(shouldError bool) *mockTx {
	return &mockTx{shouldError: shouldError}
}

func (m *mockTx) Commit() error {
	m.commitCount++
	if m.shouldError {
		return errors.New("commit")
	}
	return nil
}

func (m *mockTx) Rollback() error {
	m.rollbackCount++
	if m.shouldError {
		return errors.New("rollback")
	}
	return nil
}

var _ driver.Tx = (*mockTx)(nil)

var defaultattribute = attribute.Key("test").String("foo")

func TestOtTx_Commit(t *testing.T) {
	testCases := []struct {
		name             string
		error            bool
		noParentSpan     bool
		attributesGetter AttributesGetter
	}{
		{
			name: "no error",
		},
		{
			name:  "with error",
			error: true,
		},
		{
			name:         "no parent span",
			noParentSpan: true,
		},
		{
			name:             "with attribute getter",
			attributesGetter: getDummyAttributesGetter(),
		},
	}

	for _, spanFilterFn := range []SpanFilter{nil, omit, keep} {
		testname := "spanFilterOmit"
		if spanFilterFn == nil {
			testname = "spanFilterNil"
		} else if spanFilterFn(nil, "", "", []driver.NamedValue{}) {
			testname = "spanFilterKeep"
		}

		t.Run(testname, func(t *testing.T) {
			for _, tc := range testCases {
				t.Run(tc.name, func(t *testing.T) {
					// Prepare traces
					ctx, sr, tracer, dummySpan := prepareTraces(tc.noParentSpan)
					mt := newMockTx(tc.error)

					// New tx
					t.Setenv("OTEL_SEMCONV_STABILITY_OPT_IN", "database")
					cfg := newConfig()
					cfg.Tracer = tracer
					cfg.SpanOptions.SpanFilter = spanFilterFn
					cfg.AttributesGetter = tc.attributesGetter
					cfg.InstrumentAttributesGetter = InstrumentAttributesGetter(tc.attributesGetter)
					tx := newTx(ctx, mt, cfg)
					// Commit
					err := tx.Commit()
					if tc.error {
						require.Error(t, err)
					} else {
						require.NoError(t, err)
					}

					spanList := sr.Ended()
					omit := !filterSpan(ctx, cfg.SpanOptions, MethodTxCommit, "", []driver.NamedValue{})
					expectedSpanCount := getExpectedSpanCount(tc.noParentSpan, omit)
					// One dummy span and one span created in tx
					require.Len(t, spanList, expectedSpanCount)

					assertSpanList(t, spanList, spanAssertionParameter{
						parentSpan:         dummySpan,
						error:              tc.error,
						expectedAttributes: cfg.Attributes,
						method:             MethodTxCommit,
						noParentSpan:       tc.noParentSpan,
						attributesGetter:   tc.attributesGetter,
						omitSpan:           omit,
					})

					assert.Equal(t, 1, mt.commitCount)
				})
			}
		})
	}
}

func TestOtTx_Rollback(t *testing.T) {
	testCases := []struct {
		name             string
		error            bool
		noParentSpan     bool
		attributesGetter AttributesGetter
	}{
		{
			name: "no error",
		},
		{
			name:  "with error",
			error: true,
		},
		{
			name:         "no parent span",
			noParentSpan: true,
		},
		{
			name:             "with attribute getter",
			attributesGetter: getDummyAttributesGetter(),
		},
	}

	for _, spanFilterFn := range []SpanFilter{nil, omit, keep} {
		testname := "spanFilterOmit"
		if spanFilterFn == nil {
			testname = "spanFilterNil"
		} else if spanFilterFn(nil, "", "", []driver.NamedValue{}) {
			testname = "spanFilterKeep"
		}

		t.Run(testname, func(t *testing.T) {
			for _, tc := range testCases {
				t.Run(tc.name, func(t *testing.T) {
					// Prepare traces
					ctx, sr, tracer, dummySpan := prepareTraces(tc.noParentSpan)
					mt := newMockTx(tc.error)

					// New tx
					t.Setenv("OTEL_SEMCONV_STABILITY_OPT_IN", "database")
					cfg := newConfig()
					cfg.Tracer = tracer
					cfg.SpanOptions.SpanFilter = spanFilterFn
					cfg.AttributesGetter = tc.attributesGetter
					cfg.InstrumentAttributesGetter = InstrumentAttributesGetter(tc.attributesGetter)
					tx := newTx(ctx, mt, cfg)

					// Rollback
					err := tx.Rollback()
					if tc.error {
						require.Error(t, err)
					} else {
						require.NoError(t, err)
					}

					spanList := sr.Ended()
					omit := !filterSpan(ctx, cfg.SpanOptions, MethodTxRollback, "", []driver.NamedValue{})
					expectedSpanCount := getExpectedSpanCount(tc.noParentSpan, omit)
					// One dummy span and a span created in tx
					require.Len(t, spanList, expectedSpanCount)

					assertSpanList(t, spanList, spanAssertionParameter{
						parentSpan:         dummySpan,
						error:              tc.error,
						expectedAttributes: cfg.Attributes,
						method:             MethodTxRollback,
						noParentSpan:       tc.noParentSpan,
						attributesGetter:   tc.attributesGetter,
						omitSpan:           omit,
					})

					assert.Equal(t, 1, mt.rollbackCount)
				})
			}
		})
	}
}