module gemini_protocol
implicit none

    integer, parameter::STATUS_INPUT      = 1
    integer, parameter::STATUS_SUCCESS    = 2
    integer, parameter::STATUS_REDIRECT   = 3
    integer, parameter::STATUS_TEMPFAIL   = 4
    integer, parameter::STATUS_PERMFAIL   = 5
    integer, parameter::STATUS_CERTREQ    = 6
    integer, parameter::STATUS_LOCALFAIL  = -1

    integer, parameter::BUFFER_SIZE = 256

contains

    function request_url(url, unit_number, server_name) result(returncode)
    use request
    use iso_c_binding
    use file_handling, only: mark_file_end
    implicit none
    
        character(*), intent(in)::url
        integer, intent(in)::unit_number
        character(*), intent(in), optional::server_name
        
        integer::returncode
        
        character(:), allocatable::server
        
        type(connection)::conn
        
        integer::bytes_received, i
        character, dimension(BUFFER_SIZE)::buffer
        
        returncode = -1
        rewind(unit_number)
        
        if(present(server_name)) then
            allocate(character(len=len_trim(server_name)) :: server)
            server = server_name
        else
            server = get_server_from_url(url)
        end if
    
        conn = open_connection(server)
        
        if(conn%code == CONNECTION_OPEN) then
            if(send_string(conn%ssl, url//c_carriage_return//c_new_line, trimming=.false.)) then
                
                bytes_received = retrieve_characters(conn%ssl, buffer)
                Print *, bytes_received
                do while(bytes_received > 0)
                
                    do i=1, bytes_received
                        write(unit_number, '(A1)', advance='no') buffer(i)
                    end do
                    
                    bytes_received = retrieve_characters(conn%ssl, buffer)
                end do
                
                call mark_file_end(unit_number)
                
                rewind(unit_number)
                read(unit_number, '(I1)') returncode
                
            else
            
                returncode = -1
                write(unit_number, *) "Send Error: Could Not Send Request"
                write(*, *) "Send Error: Could Not Send Request"
            end if
            
        else
        
            returncode = -1
            write(unit_number, *) "Connection Error: "//trim(translate_connection_code(conn%code))
            write(*, *) "Connection Error: "//trim(translate_connection_code(conn%code))
        end if
        
        call close_connection(conn)
    
    end function request_url

    subroutine get_redirect_url(unit_number, url)
    implicit none
    
        integer, intent(in)::unit_number
        character(*), intent(inout)::url
        
        character::search
        integer::i, istat
        
        rewind(unit_number)
        
        ! Status code
        read(unit_number, '(A1)', advance='no') search
        read(unit_number, '(A1)', advance='no') search
        
        ! Clear the url
        url = repeat(" ", len(url))
        
        ! At least one whitespace, but whatever...
        read(unit_number, '(A1)', advance='no') search
        do while(search == " " .or. search == CHAR(9))
            read(unit_number, '(A1)', advance='no', iostat=istat) search
        end do
        
        ! Now search contains our first url component
        i = 0
        do while(search /= CHAR(13) .and. i < len(url) .and. istat == 0)
            i = i + 1
            url(i:i) = search
            read(unit_number, '(A1)', advance='no', iostat=istat) search
        end do
        
    end subroutine get_redirect_url

end module gemini_protocol