; Differential testing: OCaml wire vs EverParse C parsers
;
; Workflow:
; 1. BUILD_EVERPARSE=1 dune build @space-wire/test/diff/gen_c
;    (generates .3d schemas, runs EverParse, produces C stubs)
; 2. BUILD_EVERPARSE=1 dune build @space-wire/test/diff/diff
;    (runs differential tests)
;
; EverParse is slow, so code generation only runs when BUILD_EVERPARSE=1.
; Generated C code can be promoted and committed for C API consumers.

; Generate .3d files from SpaceOS Wire codecs

(executable
 (name gen_schemas)
 (modules gen_schemas)
 (enabled_if
  (= %{env:BUILD_EVERPARSE=} "1"))
 (libraries space_wire_3d))

(rule
 (alias gen_schemas)
 (enabled_if
  (= %{env:BUILD_EVERPARSE=} "1"))
 (targets SpaceOSFrame.3d ErrorPayload.3d DpPayload.3d Superblock.3d)
 (deps gen_schemas.exe)
 (action
  (run ./gen_schemas.exe)))

; Generate EverParse C code and differential test infrastructure
; Run with: BUILD_EVERPARSE=1 dune build @space-wire/test/diff/gen_c

(executable
 (name gen_c)
 (modules gen_c)
 (enabled_if
  (= %{env:BUILD_EVERPARSE=} "1"))
 (libraries space_wire_3d wire.diff-gen))

(rule
 (alias gen_c)
 (enabled_if
  (= %{env:BUILD_EVERPARSE=} "1"))
 (targets
  (dir schemas)
  stubs.c
  stubs.ml
  diff_test.ml)
 (deps gen_c.exe)
 (action
  (run ./gen_c.exe schemas)))

; Compile C stubs (includes EverParse generated C)
; NOTE: Only builds with BUILD_EVERPARSE=1 after running @gen_c first

(library
 (name stubs)
 (modules stubs)
 (enabled_if
  (= %{env:BUILD_EVERPARSE=} "1"))
 (foreign_stubs
  (language c)
  (names stubs)
  (flags :standard -I schemas)))

(executable
 (name diff_test)
 (modules diff_test)
 (enabled_if
  (= %{env:BUILD_EVERPARSE=} "1"))
 (libraries stubs))

(rule
 (alias diff)
 (enabled_if
  (= %{env:BUILD_EVERPARSE=} "1"))
 (deps diff_test.exe)
 (action
  (run ./diff_test.exe)))