;this file contains definitions for return status and error handling.
;

(sc-include-once
  sph-status "foreign/sph/status")

(enum
  (dg-status-id-undefined
    dg-status-id-input-type
    dg-status-id-max-id
    dg-status-id-data-length
    dg-status-id-not-implemented
    dg-status-id-duplicate
    dg-status-id-memory
    dg-status-id-condition-unfulfilled
    dg-status-id-missing-argument-dg-root
    dg-status-id-path-not-accessible-dg-root
    dg-status-id-no-more-data dg-status-group-dg dg-status-group-lmdb dg-status-group-libc))

(define (dg-status-group-id->name a) (b8* status-i-t)
  (return
    (case* = a
      (dg-status-group-dg "sph-dg")
      (dg-status-group-lmdb "lmdb")
      (dg-status-group-libc "libc")
      (else ""))))

(define (dg-status-description a) (b8* status-t)
  (return
    (case* = a.group
      (dg-status-group-dg
        (convert-type
          (case* = a.id
            (dg-status-id-input-type "input argument is of wrong type")
            (dg-status-id-data-length "intern data too large")
            (dg-status-id-duplicate "element already exists")
            (dg-status-id-not-implemented "not implemented")
            (dg-status-id-missing-argument-dg-root "missing argument 'dg-root'")
            (dg-status-id-path-not-accessible-dg-root "root not accessible")
            (dg-status-id-memory "not enough memory or other memory allocation error")
            (dg-status-id-max-id "maximum identifier value has been reached")
            (dg-status-id-condition-unfulfilled "condition unfulfilled")
            (dg-status-id-no-more-data "no more data to read")
            (else ""))
          b8*))
      (dg-status-group-lmdb (convert-type (mdb-strerror a.id) b8*))
      (else (convert-type "" b8*)))))

(define (dg-status-name a) (b8* status-t)
  (return
    (case* = a.group
      (dg-status-group-dg
        (convert-type
          (case* = a.id
            (dg-status-id-input-type "input-type")
            (dg-status-id-data-length "data-length")
            (dg-status-id-duplicate "duplicate")
            (dg-status-id-not-implemented "not-implemented")
            (dg-status-id-missing-argument-dg-root "missing-argument-dg-root")
            (dg-status-id-path-not-accessible-dg-root "path-not-accessible-dg-root")
            (dg-status-id-memory "memory")
            (dg-status-id-max-id "max-id-reached")
            (dg-status-id-condition-unfulfilled "condition-unfulfilled")
            (dg-status-id-no-more-data "no-more-data")
            (else "unknown"))
          b8*))
      (dg-status-group-lmdb (convert-type (mdb-strerror a.id) b8*))
      (else (convert-type "unknown" b8*)))))

(pre-define (dg-status-set-id-goto status-id) (status-set-both-goto dg-status-group-dg status-id))

(pre-define (dg-status-require-read! expression)
  (set status expression)
  (if (not (or status-success? (status-id-is? dg-status-id-no-more-data))) status-goto))

(pre-define dg-status-no-more-data-if-mdb-notfound
  (if dg-mdb-status-notfound? (status-set-both dg-status-group-dg dg-status-id-no-more-data)))

(pre-define dg-status-success-if-mdb-notfound
  (if dg-mdb-status-notfound? (status-set-id status-id-success)))

(pre-define dg-status-success-if-no-more-data
  (if (status-id-is? dg-status-id-no-more-data) (struct-set status id status-id-success)))

(pre-define dg-mdb-status-success? (status-id-is? MDB-SUCCESS))
(pre-define dg-mdb-status-failure? (not dg-mdb-status-success?))
(pre-define dg-mdb-status-notfound? (status-id-is? MDB-NOTFOUND))
(pre-define (dg-mdb-status-set-id-goto id) (status-set-both-goto dg-status-group-lmdb id))

(pre-define (dg-mdb-status-require! expression)
  (status-set-id expression)
  (if dg-mdb-status-failure? (status-set-group-goto dg-status-group-lmdb)))

(pre-define dg-mdb-status-require
  (if dg-mdb-status-failure? (status-set-group-goto dg-status-group-lmdb)))

(pre-define dg-mdb-status-require-read
  (if (not (or dg-mdb-status-success? dg-mdb-status-notfound?))
    (status-set-group-goto dg-status-group-lmdb)))

(pre-define (dg-mdb-status-require-read! expression)
  (status-set-id expression)
  dg-mdb-status-require-read)

(pre-define dg-mdb-status-require-notfound
  (if (not dg-mdb-status-notfound?) (status-set-group-goto dg-status-group-lmdb)))