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

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

type mockConnector struct {
	driver driver.Driver

	shouldError    bool
	connectContext context.Context
	connectCount   int
}

func newMockConnector(driver driver.Driver, shouldError bool) *mockConnector {
	return &mockConnector{driver: driver, shouldError: shouldError}
}

func (m *mockConnector) Connect(ctx context.Context) (driver.Conn, error) {
	m.connectContext = ctx
	m.connectCount++
	if m.shouldError {
		return nil, errors.New("connect")
	}
	return newMockConn(false), nil
}

func (m *mockConnector) Driver() driver.Driver {
	return m.driver
}

var _ driver.Connector = (*mockConnector)(nil)

func TestNewConnector(t *testing.T) {
	mConnector := newMockConnector(nil, false)
	otelDriver := &otDriver{}

	connector := newConnector(mConnector, otelDriver)

	assert.Equal(t, mConnector, connector.Connector)
	assert.Equal(t, otelDriver, connector.otDriver)
}

//nolint:gocognit
func TestOtConnector_Connect(t *testing.T) {
	for _, omitConnectorConnect := range []bool{true, false} {
		var testname string
		if omitConnectorConnect {
			testname = "OmitConnectorConnect"
		}

		t.Run(testname, func(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 := testSpanFilterOmit
				if spanFilterFn == nil {
					testname = testSpanFilterNil
				} else if spanFilterFn(nil, "", "", []driver.NamedValue{}) {
					testname = testSpanFilterKeep
				}

				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)

							t.Setenv("OTEL_SEMCONV_STABILITY_OPT_IN", "database")
							cfg := newConfig()
							cfg.Tracer = tracer
							cfg.SpanOptions.OmitConnectorConnect = omitConnectorConnect
							cfg.SpanOptions.SpanFilter = spanFilterFn
							cfg.AttributesGetter = tc.attributesGetter
							cfg.InstrumentAttributesGetter = InstrumentAttributesGetter(tc.attributesGetter)
							mConnector := newMockConnector(nil, tc.error)
							connector := newConnector(mConnector, &otDriver{cfg: cfg})
							conn, err := connector.Connect(ctx)
							if tc.error {
								require.Error(t, err)
							} else {
								otelConn, ok := conn.(*otConn)
								require.True(t, ok)
								assert.IsType(t, &mockConn{}, otelConn.Conn)
							}

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

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

							assert.Equal(t, 1, mConnector.connectCount)
						})
					}
				})
			}
		})
	}
}

func TestOtConnector_Driver(t *testing.T) {
	otelDriver := &otDriver{}
	connector := newConnector(nil, otelDriver)

	assert.Equal(t, otelDriver, connector.Driver())
}