// 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"
	"go.opentelemetry.io/otel/attribute"
	semconv "go.opentelemetry.io/otel/semconv/v1.30.0"
)

type MockStmt interface {
	driver.Stmt

	ExecContextCount() int
	ExecContextArgs() []driver.NamedValue
	ExecArgs() []driver.Value

	QueryContextCount() int
	QueryContextArgs() []driver.NamedValue
	QueryArgs() []driver.Value
}

type mockStmt struct {
	driver.Stmt

	shouldError bool
	queryCount  int
	execCount   int

	queryContextArgs []driver.NamedValue
	execContextArgs  []driver.NamedValue
}

func (m *mockStmt) QueryArgs() []driver.Value {
	return nil
}

func (m *mockStmt) QueryContextCount() int {
	return m.queryCount
}

func (m *mockStmt) QueryContextArgs() []driver.NamedValue {
	return m.queryContextArgs
}

func (m *mockStmt) ExecArgs() []driver.Value {
	return nil
}

func (m *mockStmt) ExecContextCount() int {
	return m.execCount
}

func (m *mockStmt) ExecContextArgs() []driver.NamedValue {
	return m.execContextArgs
}

func newMockStmt(shouldError bool) *mockStmt {
	return &mockStmt{shouldError: shouldError}
}

func (m *mockStmt) CheckNamedValue(_ *driver.NamedValue) error {
	if m.shouldError {
		return errors.New("checkNamedValue")
	}
	return nil
}

func (m *mockStmt) QueryContext(_ context.Context, args []driver.NamedValue) (driver.Rows, error) {
	m.queryContextArgs = args
	m.queryCount++
	if m.shouldError {
		return nil, errors.New("queryContext")
	}
	return nil, nil //nolint:nilnil
}

func (m *mockStmt) ExecContext(_ context.Context, args []driver.NamedValue) (driver.Result, error) {
	m.execContextArgs = args
	m.execCount++
	if m.shouldError {
		return nil, errors.New("execContext")
	}
	return nil, nil //nolint:nilnil
}

var (
	_ driver.Stmt              = (*mockStmt)(nil)
	_ driver.StmtExecContext   = (*mockStmt)(nil)
	_ driver.StmtQueryContext  = (*mockStmt)(nil)
	_ driver.NamedValueChecker = (*mockStmt)(nil)
	_ MockStmt                 = (*mockStmt)(nil)
)

//nolint:gocognit
func TestOtStmt_ExecContext(t *testing.T) {
	query := "query"
	args := []driver.NamedValue{{Value: "foo"}}
	expectedAttrs := []attribute.KeyValue{semconv.DBQueryTextKey.String(query)}
	testCases := []struct {
		name             string
		error            bool
		noParentSpan     bool
		disableQuery     bool
		attrs            []attribute.KeyValue
		attributesGetter AttributesGetter
	}{
		{
			name:  "no error",
			attrs: expectedAttrs,
		},
		{
			name:         "no query db.statement",
			disableQuery: true,
		},
		{
			name:  "with error",
			error: true,
			attrs: expectedAttrs,
		},
		{
			name:         "no parent span",
			noParentSpan: true,
			attrs:        expectedAttrs,
		},
		{
			name:             "with attribute getter",
			attributesGetter: getDummyAttributesGetter(),
			attrs:            expectedAttrs,
		},
	}

	for _, legacy := range []bool{true, false} {
		var testname string
		if legacy {
			testname = "Legacy"
		}

		t.Run(testname, func(t *testing.T) {
			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)

							var ms MockStmt
							if legacy {
								ms = newMockLegacyStmt(tc.error)
							} else {
								ms = newMockStmt(tc.error)
							}

							// New stmt
							t.Setenv("OTEL_SEMCONV_STABILITY_OPT_IN", "database")
							cfg := newConfig()
							cfg.Tracer = tracer
							cfg.SpanOptions.DisableQuery = tc.disableQuery
							cfg.SpanOptions.SpanFilter = spanFilterFn
							cfg.AttributesGetter = tc.attributesGetter
							cfg.InstrumentAttributesGetter = InstrumentAttributesGetter(tc.attributesGetter)
							stmt := newStmt(ms, cfg, query, nil)
							// Exec
							_, err := stmt.ExecContext(ctx, args)
							if tc.error {
								require.Error(t, err)
							} else {
								require.NoError(t, err)
							}

							spanList := sr.Ended()
							omit := !filterSpan(ctx, cfg.SpanOptions, MethodStmtExec, query, args)
							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: append(cfg.Attributes, tc.attrs...),
								method:             MethodStmtExec,
								noParentSpan:       tc.noParentSpan,
								attributesGetter:   tc.attributesGetter,
								omitSpan:           omit,
								query:              query,
								args:               args,
							})

							assert.Equal(t, 1, ms.ExecContextCount())
							if ms.ExecContextArgs() != nil {
								assert.Equal(t, []driver.NamedValue{{Value: "foo"}}, ms.ExecContextArgs())
							} else {
								assert.Equal(t, []driver.Value{"foo"}, ms.ExecArgs())
							}
						})
					}
				})
			}
		})
	}
}

//nolint:gocognit,cyclop
func TestOtStmt_QueryContext(t *testing.T) {
	query := "query"
	args := []driver.NamedValue{{Value: "foo"}}
	expectedAttrs := []attribute.KeyValue{semconv.DBQueryTextKey.String(query)}
	testCases := []struct {
		name             string
		error            bool
		noParentSpan     bool
		disableQuery     bool
		attrs            []attribute.KeyValue
		attributesGetter AttributesGetter
	}{
		{
			name:  "no error",
			attrs: expectedAttrs,
		},
		{
			name:         "no query db.statement",
			disableQuery: true,
		},
		{
			name:  "with error",
			error: true,
			attrs: expectedAttrs,
		},
		{
			name:         "no parent span",
			noParentSpan: true,
			attrs:        expectedAttrs,
		},
		{
			name:             "with attribute getter",
			attributesGetter: getDummyAttributesGetter(),
			attrs:            expectedAttrs,
		},
	}

	for _, legacy := range []bool{true, false} {
		var testname string
		if legacy {
			testname = "Legacy"
		}

		t.Run(testname, func(t *testing.T) {
			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)

							var ms MockStmt
							if legacy {
								ms = newMockLegacyStmt(tc.error)
							} else {
								ms = newMockStmt(tc.error)
							}

							// New stmt
							t.Setenv("OTEL_SEMCONV_STABILITY_OPT_IN", "database")
							cfg := newConfig()
							cfg.Tracer = tracer
							cfg.SpanOptions.DisableQuery = tc.disableQuery
							cfg.SpanOptions.SpanFilter = spanFilterFn
							cfg.AttributesGetter = tc.attributesGetter
							cfg.InstrumentAttributesGetter = InstrumentAttributesGetter(tc.attributesGetter)
							stmt := newStmt(ms, cfg, query, nil)
							// Query
							rows, err := stmt.QueryContext(ctx, args)
							if tc.error {
								require.Error(t, err)
							} else {
								require.NoError(t, err)
							}

							spanList := sr.Ended()
							omit := !filterSpan(ctx, cfg.SpanOptions, MethodStmtQuery, query, args)
							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: append(cfg.Attributes, tc.attrs...),
								method:             MethodStmtQuery,
								noParentSpan:       tc.noParentSpan,
								attributesGetter:   tc.attributesGetter,
								omitSpan:           omit,
								query:              query,
								args:               args,
							})

							assert.Equal(t, 1, ms.QueryContextCount())
							if ms.QueryContextArgs() != nil {
								assert.Equal(t, []driver.NamedValue{{Value: "foo"}}, ms.QueryContextArgs())
							} else {
								assert.Equal(t, []driver.Value{"foo"}, ms.QueryArgs())
							}
							if !tc.error {
								assert.IsType(t, &otRows{}, rows)
							}
						})
					}
				})
			}
		})
	}
}

type namedValueChecker struct{ err error }

func (nvc *namedValueChecker) CheckNamedValue(_ *driver.NamedValue) error {
	return nvc.err
}

func TestOtStmt_CheckNamedValue(t *testing.T) {
	t.Setenv("OTEL_SEMCONV_STABILITY_OPT_IN", "database")
	// Generate a variable that implements the driver.NamedValueChecker

	testCases := []struct {
		name   string
		stmt   driver.Stmt
		otConn *otConn
		err    error
	}{
		{
			name:   "stmt and conn do not implement NamedValueChecker",
			stmt:   newMockLegacyStmt(false),
			otConn: newConn(&mockConn{}, newConfig()),
			err:    driver.ErrSkip,
		},
		{
			name: "only stmt implements NamedValueChecker",
			stmt: &struct {
				driver.Stmt
				driver.NamedValueChecker
			}{NamedValueChecker: &namedValueChecker{}},
		},
		{
			name: "only stmt implements NamedValueChecker, but has error",
			stmt: &struct {
				driver.Stmt
				driver.NamedValueChecker
			}{NamedValueChecker: &namedValueChecker{err: assert.AnError}},
			err: assert.AnError,
		},
		{
			name: "only conn implements NamedValueChecker",
			stmt: newMockLegacyStmt(false),
			otConn: newConn(&struct {
				driver.Conn
				driver.NamedValueChecker
			}{NamedValueChecker: &namedValueChecker{}}, newConfig()),
		},
		{
			name: "only conn implements NamedValueChecker, but has error",
			stmt: newMockLegacyStmt(false),
			otConn: newConn(&struct {
				driver.Conn
				driver.NamedValueChecker
			}{NamedValueChecker: &namedValueChecker{err: assert.AnError}}, newConfig()),
			err: assert.AnError,
		},
	}

	for _, tc := range testCases {
		t.Run(tc.name, func(t *testing.T) {
			stmt := newStmt(tc.stmt, newConfig(), "", tc.otConn)
			err := stmt.CheckNamedValue(nil)
			assert.Equal(t, tc.err, err)
		})
	}
}