vorteil/direktiv

package instancestoresql

import (
    "fmt"
    "strings"
    "time"

    "github.com/direktiv/direktiv/pkg/refactor/instancestore"
)

func wheres(clauses ...string) string {
    if len(clauses) == 0 {
        return ""
    }
    if len(clauses) == 1 {
        return ` WHERE ` + clauses[0]
    }

    return ` WHERE (` + strings.Join(clauses, ") AND (") + `)`
}

func generateGetInstancesOrderings(opts *instancestore.ListOpts) (string, error) {
    if opts == nil || len(opts.Orders) == 0 {
        return ` ORDER BY ` + fieldCreatedAt + " " + desc, nil
    }

    keys := make(map[string]bool)
    orderStrings := []string{}
    for _, order := range opts.Orders {
        var s string
        switch order.Field {
        case instancestore.FieldCreatedAt:
            s = fieldCreatedAt
        default:
            return "", fmt.Errorf("order field '%s': %w", order.Field, instancestore.ErrBadListOpts)
        }

        if _, exists := keys[order.Field]; exists {
            return "", fmt.Errorf("duplicate order field '%s': %w", order.Field, instancestore.ErrBadListOpts)
        }

        keys[order.Field] = true

        if order.Descending {
            s += " " + desc
        }

        orderStrings = append(orderStrings, s)
    }

    return ` ORDER BY ` + strings.Join(orderStrings, ", "), nil
}

//nolint:gocognit,goconst
func generateGetInstancesFilters(opts *instancestore.ListOpts) ([]string, []interface{}, error) {
    if opts == nil {
        return []string{}, []interface{}{}, nil
    }

    clauses := []string{}
    vals := []interface{}{}
    for idx := range opts.Filters {
        filter := opts.Filters[idx]
        var clause string
        var val interface{}
        switch filter.Field {
        case fieldNamespaceID:
            if filter.Kind == instancestore.FilterKindMatch {
                clause = fieldNamespaceID + " = ?"
                val = filter.Value
            } else {
                return nil, nil, fmt.Errorf("filter kind '%s' for use with field '%s': %w", filter.Kind, filter.Field, instancestore.ErrBadListOpts)
            }
        case instancestore.FieldCreatedAt:
            if t, ok := filter.Value.(time.Time); ok {
                filter.Value = t.UTC()
            }

            if t, ok := filter.Value.(*time.Time); ok {
                filter.Value = t.UTC()
            }

            if filter.Kind == instancestore.FilterKindBefore {
                clause = fieldCreatedAt + " < ?"
                val = filter.Value
            } else if filter.Kind == instancestore.FilterKindAfter {
                clause = fieldCreatedAt + " > ?"
                val = filter.Value
            } else {
                return nil, nil, fmt.Errorf("filter kind '%s' for use with field '%s': %w", filter.Kind, filter.Field, instancestore.ErrBadListOpts)
            }

        case fieldDeadline:
            if t, ok := filter.Value.(time.Time); ok {
                filter.Value = t.UTC()
            }

            if t, ok := filter.Value.(*time.Time); ok {
                filter.Value = t.UTC()
            }

            if filter.Kind == instancestore.FilterKindBefore {
                clause = fieldDeadline + " < ?"
                val = filter.Value
            } else if filter.Kind == instancestore.FilterKindAfter {
                clause = fieldDeadline + " > ?"
                val = filter.Value
            } else {
                return nil, nil, fmt.Errorf("filter kind '%s' for use with field '%s': %w", filter.Kind, filter.Field, instancestore.ErrBadListOpts)
            }

        case instancestore.FieldWorkflowPath:
            if filter.Kind == instancestore.FilterKindMatch {
                clause = fieldWorkflowPath + " = ?"
                val = fmt.Sprintf("%s", filter.Value)
            } else if filter.Kind == instancestore.FilterKindPrefix {
                clause = fieldWorkflowPath + " LIKE ?"
                val = fmt.Sprintf("%s", filter.Value) + "%"
            } else if filter.Kind == instancestore.FilterKindContains {
                clause = fieldWorkflowPath + " LIKE ?"
                val = "%" + fmt.Sprintf("%s", filter.Value) + "%"
            } else {
                return nil, nil, fmt.Errorf("filter kind '%s' for use with field '%s': %w", filter.Kind, filter.Field, instancestore.ErrBadListOpts)
            }

        case instancestore.FieldStatus:
            if filter.Kind == instancestore.FilterKindMatch {
                clause = fieldStatus + " = ?"
                val = filter.Value
            } else if filter.Kind == "<" {
                clause = fieldStatus + " < ?"
                val = filter.Value
            } else {
                return nil, nil, fmt.Errorf("filter kind '%s' for use with field '%s': %w", filter.Kind, filter.Field, instancestore.ErrBadListOpts)
            }

        case instancestore.FieldInvoker:
            if filter.Kind == instancestore.FilterKindMatch {
                clause = fieldInvoker + " = ?"
                val = fmt.Sprintf("%s", filter.Value)
            } else if filter.Kind == instancestore.FilterKindContains {
                clause = fieldInvoker + " LIKE ?"
                val = "%" + fmt.Sprintf("%s", filter.Value) + "%"
            } else {
                return nil, nil, fmt.Errorf("filter kind '%s' for use with field '%s': %w", filter.Kind, filter.Field, instancestore.ErrBadListOpts)
            }

        default:
            return nil, nil, fmt.Errorf("filter field '%s': %w", filter.Field, instancestore.ErrBadListOpts)
        }

        clauses = append(clauses, clause)
        vals = append(vals, val)
    }

    return clauses, vals, nil
}

func generateInsertQuery(table string, columns []string) string {
    into := strings.Join(columns, ", ")
    valPlaceholders := strings.Repeat("?, ", len(columns)-1) + "?"
    query := fmt.Sprintf(`INSERT INTO %s(%s) VALUES (%s)`, table, into, valPlaceholders)

    return query
}

func generateGetInstancesQueries(columns []string, opts *instancestore.ListOpts) (string, string, []interface{}, error) {
    clauses, vals, err := generateGetInstancesFilters(opts)
    if err != nil {
        return "", "", nil, err
    }

    orderings, err := generateGetInstancesOrderings(opts)
    if err != nil {
        return "", "", nil, err
    }

    countQuery := fmt.Sprintf(`SELECT COUNT(*) FROM %s`, table)
    countQuery += wheres(clauses...)

    query := fmt.Sprintf(`SELECT %s FROM %s`, strings.Join(columns, ", "), table)
    query += wheres(clauses...)
    query += orderings

    if opts != nil && opts.Limit > 0 {
        query += fmt.Sprintf(` LIMIT %d`, opts.Limit)

        if opts.Offset > 0 {
            query += fmt.Sprintf(` OFFSET %d`, opts.Offset)
        }
    }

    return countQuery, query, vals, nil
}