# Copyright (c) 2017, 2023, Oracle and/or its affiliates. All rights reserved.
# DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
#
# This code is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License version 2 only, as
# published by the Free Software Foundation.  Oracle designates this
# particular file as subject to the "Classpath" exception as provided
# by Oracle in the LICENSE file that accompanied this code.
#
# This code is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
# version 2 for more details (a copy is included in the LICENSE file that
# accompanied this code).
#
# You should have received a copy of the GNU General Public License version
# 2 along with this work; if not, write to the Free Software Foundation,
# Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
#
# Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
# or visit www.oracle.com if you need additional information or have any
# questions.
#

ifeq ($(_MAKEBASE_GMK), )
  $(error You must include MakeBase.gmk prior to including ProcessMarkdown.gmk)
endif

include TextFileProcessing.gmk

# Helper function for SetupProcessMarkdown
# $1: The $1 from SetupProcessMarkdown
# $2: The name of the current source file, relative to the dir given in $3
# $3: The directory of the current source file
define ProcessMarkdown
  $1_$2_OUTPUT_FILE := $$($1_DEST)/$$(basename $2)$$($1_FILE_EXT)
  $1_$2_TARGET_DIR := $$(dir $$($1_$2_OUTPUT_FILE))
  $1_$2_INPUT_FILE := $3/$2
  $1_$2_MARKER := $$(subst /,_,$1_$2)

  # Only continue if this target file hasn't been processed already. This lets
  # the first found source file override any other with the same name.
  ifeq ($$($1_$2_OUTPUT_FILE_PROCESSED), )
    $1_$2_OUTPUT_FILE_PROCESSED := true

    ifneq ($$($1_REPLACEMENTS), )
      $1_$2_PANDOC_INPUT := $$(SUPPORT_OUTPUTDIR)/markdown/$$($1_$2_MARKER)_pre.tmp

      $$(eval $$(call SetupTextFileProcessing, $1_$2_PREPROCESSED, \
          SOURCE_FILES := $$($1_$2_INPUT_FILE), \
          OUTPUT_FILE := $$($1_$2_PANDOC_INPUT), \
          REPLACEMENTS := $$($1_REPLACEMENTS), \
      ))
    else
      $1_$2_PANDOC_INPUT := $$($1_$2_INPUT_FILE)
    endif

    ifneq ($$($1_POST_PROCESS), )
      $1_$2_PANDOC_OUTPUT := $$(SUPPORT_OUTPUTDIR)/markdown/$$($1_$2_MARKER)_post.tmp
    else
      $1_$2_PANDOC_OUTPUT := $$($1_$2_OUTPUT_FILE)
    endif

    ifneq ($$($1_CSS), )
      ifneq ($$(findstring https:/, $$($1_CSS)), )
        $1_$2_CSS_OPTION := --css '$$($1_CSS)'
      else
        $1_$2_CSS := $$(strip $$(call RelativePath, $$($1_CSS), $$($1_$2_TARGET_DIR)))
        $1_$2_CSS_OPTION := --css '$$($1_$2_CSS)'
      endif
    endif

    # This does not need to be included in VARDEPS since it's from the actual
    # source file. Only run the shell if the recipe gets executed below.
    $1_$2_OPTIONS_FROM_SRC = \
        $$(shell $$(GREP) _pandoc-options_: $3/$2 | $$(CUT) -d : -f 2-)

    ifneq ($$($1_FILTER), )
      $1_$2_OPTIONS := --filter $$($1_FILTER)
    endif

    $1_$2_VARDEPS := $$($1_OPTIONS) $$($1_$2_OPTIONS) $$($1_CSS) \
        $$($1_REPLACEMENTS) $$($1_POST_PROCESS)
    $1_$2_VARDEPS_FILE := $$(call DependOnVariable, $1_$2_VARDEPS, \
        $$(SUPPORT_OUTPUTDIR)/markdown/$$($1_$2_MARKER).vardeps)

    $$($1_$2_PANDOC_OUTPUT): $$($1_$2_PANDOC_INPUT) $$($1_$2_VARDEPS_FILE) $$($1_EXTRA_DEPS)
	$$(call LogInfo, Converting $2 to $$($1_FORMAT))
	$$(call MakeDir, $$(SUPPORT_OUTPUTDIR)/markdown $$(dir $$($1_$2_PANDOC_OUTPUT)))
	$$(call ExecuteWithLog, $$(SUPPORT_OUTPUTDIR)/markdown/$$($1_$2_MARKER), \
	    $$(PANDOC) $$($1_OPTIONS) -f $$(PANDOC_MARKDOWN_FLAG) \
	    -t $$($1_FORMAT) --eol=lf --standalone \
	    $$($1_$2_CSS_OPTION) $$($1_$2_OPTIONS_FROM_SRC) $$($1_$2_OPTIONS) \
	    '$$($1_$2_PANDOC_INPUT)' -o '$$($1_$2_PANDOC_OUTPUT)')
        ifneq ($$(findstring $$(LOG_LEVEL), debug trace), )
	  TOO_LONG_LINES=`$$(GREP) -E -e '^.{80}.+$$$$' $$<` || true ; \
	  if [ "x$$$$TOO_LONG_LINES" != x ]; then \
	    $$(ECHO) "Warning: Unsuitable markdown in $$<:" ; \
	    $$(ECHO) "The following lines are longer than 80 characters:" ; \
	    $$(GREP) -E -n -e '^.{80}.+$$$$' $$< || true ; \
	  fi
        endif

    # If we have no post processing, PANDOC_OUTPUT is set to OUTPUT_FILE. Otherwise
    # PANDOC_OUTPUT is a temporary file, and we must now create the real OUTPUT_FILE.
    ifneq ($$($1_POST_PROCESS), )
      $$($1_$2_OUTPUT_FILE): $$($1_$2_PANDOC_OUTPUT)
	$$(call LogInfo, Post-processing markdown file $2)
	$$(call MakeDir, $$(SUPPORT_OUTPUTDIR)/markdown $$($1_$2_TARGET_DIR))
	$$(call ExecuteWithLog, $$(SUPPORT_OUTPUTDIR)/markdown/$$($1_$2_MARKER)_post, \
	    ( $$($1_POST_PROCESS) $$($1_$2_PANDOC_OUTPUT) > $$($1_$2_OUTPUT_FILE) ) )
    endif

    $1 += $$($1_$2_OUTPUT_FILE)
  endif
endef

################################################################################
# Setup make rules for converting a markdown file to html.
#
# Parameter 1 is the name of the rule. This name is used as variable prefix,
# and the targets generated are listed in a variable by that name.
#
# Remaining parameters are named arguments. These include:
#   DEST     : Destination root dir
#   FILES    : List of files to copy with absolute paths, or path relative to SRC.
#   SRC      : Source root dir; if given keep input files hierarchy relative to
#              SRC in DEST, otherwise flatten structure into DEST.
#   FORMAT   : The target format (defaults to html5)
#   FILE_EXT : The file extension to replace .md with (defaults to .html)
#   OPTIONS  : Additional options to pandoc
#   EXTRA_DEPS : Additional dependencies to add to each pandoc call
#   FILTER   : Optional pandoc filter command
#   POST_PROCESS : Optional command-line to post-process generated markdown
#   REPLACEMENTS : Text replacements to perform on input file before processing
#
SetupProcessMarkdown = $(NamedParamsMacroTemplate)
define SetupProcessMarkdownBody
  ifeq ($$($1_FILES), )
    $$(error FILES is missing in SetupProcessMarkdown $1)
  endif

  ifeq ($$($1_DEST), )
    $$(error DEST is missing in SetupProcessMarkdown $1)
  endif

  # If no target format is specified, default to html5.
  ifeq ($$($1_FORMAT), )
    $1_FORMAT := html5
  endif

  ifeq ($$($1_FORMAT), man)
    # If no file extension is specified, default to '.1'.
    ifeq ($$($1_FILE_EXT), )
      $1_FILE_EXT := .1
    endif
  else ifeq ($$($1_FORMAT), html5)
    ifeq ($$($1_FILE_EXT), )
      $1_FILE_EXT := .html
    endif
  else ifeq ($$($1_FORMAT), html)
    ifeq ($$($1_FILE_EXT), )
      $1_FILE_EXT := .html
    endif
  endif

  # Remove any trailing slash
  $1_DEST := $$(patsubst %/,%,$$($1_DEST))

  ifeq ($$($1_SRC), )
    # No SRC given, assume we're flattening all files into output dir.
    $$(foreach f, $$($1_FILES), \
      $$(eval $$(call ProcessMarkdown,$1,$$(notdir $$f),$$(patsubst %/,%,$$(dir $$f)))) \
    )
  else
    # Remove any trailing slash
    $1_SRC := $$(patsubst %/,%,$$($1_SRC))

    $$(foreach f, $$(patsubst $$($1_SRC)/%,%,$$($1_FILES)), \
      $$(eval $$(call ProcessMarkdown,$1,$$f,$$($1_SRC))) \
    )
  endif
endef