Add diff pdf generator

paper/Makefile

@@ -8,6 +8,8 @@ SHELL := bash
 MAKEFLAGS += --warn-undefined-variables
 MAKEFLAGS += --no-builtin-rules
 
+DIFF_VERSION ?= v2.0
+
 main_tex ?= ihsm_paper
 brief_tex ?= ihsm_tech_report
 
@@ -15,6 +17,12 @@ VERSION_STRING := $(shell git describe --tags --long --dirty)
 
 all: ${main_tex}.pdf ${brief_tex}.pdf
 
+.PHONY: diff
+diff: ihsm_paper_diff.pdf
+
+ihsm_paper_diff.tex: ihsm_paper.tex ihsm.bib
+	python3 diffinator.py $^ $(DIFF_VERSION) > $@
+
 %.pdf: %.tex ihsm.bib version.tex
 	pdflatex -shell-escape $<
 	biber $* 

paper/diffinator.py

@@ -0,0 +1,78 @@
+#!/usr/bin/env python3
+
+import re
+import subprocess
+
+import click
+
+
+@click.command()
+@click.argument('texfile')
+@click.argument('bibliography')
+@click.argument('revision')
+def generate_git_tex_diff(texfile, bibliography, revision):
+    with open(texfile) as f:
+        tex_lines = len(list(f))
+    with open(bibliography) as f:
+        bib_lines = len(list(f))
+
+    tex_proc = subprocess.run(['git', 'diff', f'-U{tex_lines+1}', '--word-diff', '--color=always', revision, texfile],
+            check=True, capture_output=True)
+
+    bib_proc = subprocess.run(['git', 'diff', f'-U{bib_lines+1}', '--word-diff', '--color=always', revision, bibliography],
+            check=True, capture_output=True)
+
+    addition_re = re.compile('\033\\[32m\\{\\+(.*?)\\+\\}\033\\[m')
+    deletion_re = re.compile('\033\\[31m\\[-(.*?)\\-]\033\\[m')
+    csi_re = re.compile('\033\\[.*?m')
+    bibtex_entry_def_re = re.compile('@.*?{(.*?),')
+
+    bibliography_categories  = '\\DeclareBibliographyCategory{diff_new_entry}\n'
+    bibliography_categories += '\\DeclareBibliographyCategory{diff_deleted_entry}\n'
+    bibliography_categories += '\\AtEveryBibitem{\\ifcategory{diff_new_entry}{\\color{diffgreen}}{\\ifcategory{diff_deleted_entry}{\\color{diffred}}{\\color{black}}}}\n'
+
+    added_entries, removed_entries = [], []
+    for line in bib_proc.stdout.decode().splitlines():
+        if (match := addition_re.fullmatch(line.strip())):
+            if (entry_def := bibtex_entry_def_re.fullmatch(match.group(1))):
+                added_entries.append(entry_def.group(1))
+
+        if (match := deletion_re.fullmatch(line.strip())):
+            if (entry_def := bibtex_entry_def_re.fullmatch(match.group(1))):
+                removed_entries.append(entry_def.group(1))
+
+    if added_entries:
+        bibliography_categories += '\\addtocategory{diff_new_entry}{' + ','.join(added_entries) + '}\n'
+    if removed_entries:
+        bibliography_categories += '\\addtocategory{diff_deleted_entry}{' + ','.join(removed_entries) + '}\n'
+
+    content_started = False
+    document_started = False
+    for line in tex_proc.stdout.decode().splitlines():
+
+        if not content_started:
+            if '@@' in line:
+                content_started = True
+            continue
+
+        line = line.rstrip()
+        if document_started: # diff results in preamble
+            line = addition_re.sub(r'\\color{diffgreen}\1\\color{black}', line)
+            line = deletion_re.sub(r'\\color{diffred}\1\\color{black}', line)
+
+        else:
+            if '\\begin{document}' in line:
+                document_started = True
+                print(bibliography_categories)
+                print('\\definecolor{diffgreen}{HTML}{1e8449}')
+                print('\\definecolor{diffred}{HTML}{cb4335}')
+
+
+            line = addition_re.sub(r'\1', line)
+            line = deletion_re.sub(r'\1', line)
+
+        line = csi_re.sub('', line)
+        print(line)
+
+if __name__ == '__main__':
+    generate_git_tex_diff()