package database

import (
	"context"
	"errors"
	"fmt"
	"regexp"
	"strings"
	"testing"

	"modelRT/common"

	"github.com/DATA-DOG/go-sqlmock"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"gorm.io/driver/postgres"
	"gorm.io/gorm"
)

func TestBuildMeasurementTokenValidationQuery(t *testing.T) {
	tests := []struct {
		name      string
		token     string
		wantArgs  []any
		wantWhere string
		wantErr   bool
	}{
		{
			name:      "seven-part token",
			token:     "grid.zone.station.nspath.component.bay.measurement",
			wantArgs:  []any{"grid", "zone", "station", "nspath", "component", "measurement"},
			wantWhere: "WHERE g.tagname = ?",
		},
		{
			name:      "four-part token",
			token:     "nspath.component.bay.measurement",
			wantArgs:  []any{"nspath", "component", "measurement"},
			wantWhere: "WHERE c.nspath = ?",
		},
		{
			name:      "two-part token",
			token:     "nspath.measurement",
			wantArgs:  []any{"nspath", "measurement"},
			wantWhere: "WHERE c.nspath = ?",
		},
		{
			name:    "non-bay group",
			token:   "nspath.component.rated.attribute",
			wantErr: true,
		},
		{
			name:    "empty segment",
			token:   "nspath..bay.measurement",
			wantErr: true,
		},
		{
			name:    "invalid segment count",
			token:   "grid.zone.station",
			wantErr: true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			query, args, err := buildMeasurementTokenValidationQuery(tt.token)
			if tt.wantErr {
				require.Error(t, err)
				assert.ErrorIs(t, err, common.ErrInvalidMeasurementToken)
				return
			}

			require.NoError(t, err)
			assert.Contains(t, query, "INNER JOIN component AS c ON c.global_uuid = m.component_uuid")
			assert.Contains(t, query, "INNER JOIN bay AS b ON b.bay_uuid = m.bay_uuid")
			assert.Contains(t, query, tt.wantWhere)
			assert.NotContains(t, query, "grid_idWHERE")
			assert.Regexp(t, `grid_id\s+WHERE`, query)
			assert.NotContains(t, query, "\n")
			assert.NotContains(t, query, "\t")
			assert.Equal(t, tt.wantArgs, args)
		})
	}
}

func TestValidateMeasurementToken(t *testing.T) {
	tests := []struct {
		name     string
		count    int64
		queryErr error
		wantErr  error
	}{
		{name: "exists", count: 1},
		{name: "not found", count: 0, wantErr: common.ErrMeasurementTokenNotFound},
		{name: "ambiguous", count: 2, wantErr: common.ErrAmbiguousMeasurementToken},
		{name: "query failure", queryErr: errors.New("database unavailable")},
	}

	const token = "nspath.measurement"
	query, _, err := buildMeasurementTokenValidationQuery(token)
	require.NoError(t, err)
	expectedQuery := query
	for i := 1; strings.Contains(expectedQuery, "?"); i++ {
		expectedQuery = strings.Replace(expectedQuery, "?", fmt.Sprintf("$%d", i), 1)
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			sqlDB, mock, err := sqlmock.New()
			require.NoError(t, err)
			t.Cleanup(func() { _ = sqlDB.Close() })

			db, err := gorm.Open(postgres.New(postgres.Config{Conn: sqlDB}), &gorm.Config{})
			require.NoError(t, err)

			expectation := mock.ExpectQuery(regexp.QuoteMeta(expectedQuery)).
				WithArgs("nspath", "measurement")
			if tt.queryErr != nil {
				expectation.WillReturnError(tt.queryErr)
			} else {
				expectation.WillReturnRows(sqlmock.NewRows([]string{"count"}).AddRow(tt.count))
			}

			err = ValidateMeasurementToken(context.Background(), db, token)
			if tt.wantErr != nil {
				assert.ErrorIs(t, err, tt.wantErr)
			} else if tt.queryErr != nil {
				require.Error(t, err)
				assert.Contains(t, err.Error(), tt.queryErr.Error())
			} else {
				require.NoError(t, err)
			}
			require.NoError(t, mock.ExpectationsWereMet())
		})
	}
}

func TestBuildMeasurementRowsQuerySeparatesLimitClause(t *testing.T) {
	validationQuery, _, err := buildMeasurementTokenValidationQuery("nspath.measurement")
	require.NoError(t, err)

	query := buildMeasurementRowsQuery(validationQuery)
	assert.NotContains(t, query, "?LIMIT")
	assert.Regexp(t, `m\.tag = \?\s+LIMIT 2$`, query)
	assert.NotContains(t, query, "\n")
	assert.NotContains(t, query, "\t")
}

func TestQueryMeasurementByDataObjectToken(t *testing.T) {
	sqlDB, mock, err := sqlmock.New()
	require.NoError(t, err)
	t.Cleanup(func() { _ = sqlDB.Close() })

	db, err := gorm.Open(postgres.New(postgres.Config{Conn: sqlDB}), &gorm.Config{})
	require.NoError(t, err)

	const componentUUID = "70c190f2-8a60-42a9-b143-ec5f87e0aa6b"
	mock.ExpectQuery(`(?s)SELECT m\.\*.*WHERE c\.nspath = \$1.*AND m\.tag = \$2.*LIMIT 2`).
		WithArgs("nspath", "measurement").
		WillReturnRows(sqlmock.NewRows([]string{
			"id",
			"tag",
			"name",
			"mode",
			"size",
			"data_source",
			"event_plan",
			"binding",
			"component_uuid",
		}).AddRow(
			int64(10),
			"measurement",
			"A phase current",
			int16(1),
			10,
			`{"type":1,"io_address":{"channel":"tm1"}}`,
			`{"enabled":true}`,
			`{"ct":{"ratio":1}}`,
			componentUUID,
		))
	mock.ExpectQuery(`(?s)SELECT global_uuid, nspath, tag, grid, zone, station.*WHERE global_uuid = \$1.*LIMIT 1`).
		WithArgs(componentUUID).
		WillReturnRows(sqlmock.NewRows([]string{
			"global_uuid",
			"nspath",
			"tag",
			"grid",
			"zone",
			"station",
		}).AddRow(componentUUID, "nspath", "component", "grid", "zone", "station"))

	measurement, component, err := QueryMeasurementByDataObjectToken(context.Background(), db, "nspath.measurement")
	require.NoError(t, err)
	assert.Equal(t, int64(10), measurement.ID)
	assert.Equal(t, int16(1), measurement.Mode)
	assert.Equal(t, float64(1), measurement.DataSource["type"])
	assert.Equal(t, "grid", component.GridName)
	assert.Equal(t, "component", component.Tag)
	require.NoError(t, mock.ExpectationsWereMet())
}