!> A one-shot command-line front end, useful for confirming that an instance
!> answers: `cepis --base-url http://localhost:8080 01001000`.
program main
    use, intrinsic :: iso_fortran_env, only: real64, output_unit, error_unit
    use cepis
    implicit none

    character(len=:), allocatable :: url, message
    character(len=:), allocatable :: ceps(:)
    type(cepis_client) :: client
    integer :: status
    logical :: want_health

    call parse_arguments(url, ceps, want_health)

    if (len(url) > 0) then
        call cepis_client_init(client, status, message, base_url=url)
    else
        call cepis_client_init(client, status, message)
    end if
    if (status /= CEPIS_OK) then
        write (error_unit, '(A)') 'cepis: '//message
        stop 2
    end if

    if (want_health) then
        call show_health(client)
    else if (size(ceps) == 1) then
        call show_one(client, trim(ceps(1)))
    else
        call show_many(client, ceps)
    end if

contains

    subroutine usage()
        write (error_unit, '(A)') 'usage: cepis [--base-url URL] CEP [CEP ...]'
        write (error_unit, '(A)') '       cepis [--base-url URL] --health'
        stop 2
    end subroutine usage

    subroutine parse_arguments(base, values, health)
        character(len=:), allocatable, intent(out) :: base
        character(len=:), allocatable, intent(out) :: values(:)
        logical, intent(out) :: health
        character(len=4096) :: argument
        character(len=64) :: collected(256)
        integer :: count, i, length, total

        base = ''
        health = .false.
        count = 0
        total = command_argument_count()

        i = 1
        do while (i <= total)
            call get_command_argument(i, argument, length)
            if (argument(1:length) == '--health') then
                health = .true.
            else if (argument(1:length) == '--base-url') then
                i = i + 1
                if (i > total) call usage()
                call get_command_argument(i, argument, length)
                base = argument(1:length)
            else if (argument(1:length) == '--help' .or. argument(1:length) == '-h') then
                call usage()
            else
                if (count >= size(collected)) call usage()
                count = count + 1
                collected(count) = argument(1:min(length, len(collected)))
            end if
            i = i + 1
        end do

        if (.not. health .and. count == 0) call usage()

        allocate (character(len=64) :: values(count))
        do i = 1, count
            values(i) = collected(i)
        end do
    end subroutine parse_arguments

    subroutine show_health(handle)
        type(cepis_client), intent(in) :: handle
        type(cepis_health) :: report
        integer :: code
        character(len=:), allocatable :: detail

        call handle%health(report, code, detail)
        if (code /= CEPIS_OK) then
            write (error_unit, '(A)') 'cepis: '//cepis_status_name(code)//': '//detail
            stop 1
        end if

        write (output_unit, '(A)') 'status         '//report%status
        write (output_unit, '(A)') 'dne            '//report%dne
        write (output_unit, '(A,I0)') 'ceps           ', report%ceps
        write (output_unit, '(A,I0)') 'geo            ', report%geo
        write (output_unit, '(A)') 'base_gerada_em '//report%base_gerada_em
    end subroutine show_health

    subroutine show_one(handle, cep)
        type(cepis_client), intent(in) :: handle
        character(len=*), intent(in) :: cep
        type(cepis_address) :: address
        integer :: code
        character(len=:), allocatable :: detail

        call handle%lookup(cep, address, code, detail)
        if (code /= CEPIS_OK) then
            write (error_unit, '(A)') 'cepis: '//cepis_status_name(code)//': '//detail
            stop 1
        end if

        write (output_unit, '(A)') 'cep            '//address%formatted_cep()
        write (output_unit, '(A)') 'logradouro     '//address%logradouro
        write (output_unit, '(A)') 'complemento    '//address%complemento
        write (output_unit, '(A)') 'unidade        '//address%unidade
        write (output_unit, '(A)') 'bairro         '//address%bairro
        write (output_unit, '(A)') 'localidade     '//address%localidade
        write (output_unit, '(A)') 'uf             '//address%uf
        write (output_unit, '(A)') 'estado         '//address%estado
        write (output_unit, '(A)') 'regiao         '//address%regiao
        write (output_unit, '(A)') 'ibge           '//address%ibge
        write (output_unit, '(A)') 'gia            '//address%gia
        write (output_unit, '(A)') 'ddd            '//address%ddd
        write (output_unit, '(A)') 'siafi          '//address%siafi
        if (address%has_geo) then
            write (output_unit, '(A,F0.6,A,F0.6,A,I0,A)') 'geo            ', &
                address%geo%lat, ', ', address%geo%lon, ' (', address%geo%raio_m, &
                ' m, '//address%geo%precisao//')'
        end if
    end subroutine show_one

    subroutine show_many(handle, values)
        type(cepis_client), intent(in) :: handle
        character(len=*), intent(in) :: values(:)
        type(cepis_address), allocatable :: addresses(:)
        integer :: code, i
        character(len=:), allocatable :: detail

        call handle%lookup_many(values, addresses, code, detail)
        if (code /= CEPIS_OK) then
            write (error_unit, '(A)') 'cepis: '//cepis_status_name(code)//': '//detail
            stop 1
        end if

        do i = 1, size(addresses)
            if (addresses(i)%found) then
                write (output_unit, '(A)') trim(values(i))//'  '// &
                    addresses(i)%localidade//'/'//addresses(i)%uf//'  '// &
                    addresses(i)%logradouro
            else
                write (output_unit, '(A)') trim(values(i))//'  not found'
            end if
        end do
    end subroutine show_many

end program main