1 files changed, 183 insertions, 0 deletions
diff --git a/crmsh/template.py b/crmsh/template.py
new file mode 100644
index 0000000..376f64b
--- /dev/null
+++ b/crmsh/template.py
@@ -0,0 +1,183 @@
+# Copyright (C) 2008-2011 Dejan Muhamedagic <dmuhamedagic@suse.de>
+# See COPYING for license information.
+
+import os
+import re
+from . import config
+from . import userdir
+from . import log
+
+
+logger = log.setup_logger(__name__)
+
+
+def get_var(l, key):
+    for s in l:
+        a = s.split()
+        if len(a) == 2 and a[0] == key:
+            return a[1]
+    return ''
+
+
+def chk_var(l, key):
+    for s in l:
+        a = s.split()
+        if len(a) == 2 and a[0] == key and a[1]:
+            return True
+    return False
+
+
+def chk_key(l, key):
+    for s in l:
+        a = s.split()
+        if len(a) >= 1 and a[0] == key:
+            return True
+    return False
+
+
+def validate_template(l):
+    'Test for required stuff in a template.'
+    if not chk_var(l, '%name'):
+        logger.error("invalid template: missing '%name'")
+        return False
+    if not chk_key(l, '%generate'):
+        logger.error("invalid template: missing '%generate'")
+        return False
+    g = l.index('%generate')
+    if not (chk_key(l[0:g], '%required') or chk_key(l[0:g], '%optional')):
+        logger.error("invalid template: missing '%required' or '%optional'")
+        return False
+    return True
+
+
+def fix_tmpl_refs(l, ident, pfx):
+    for i, tmpl in enumerate(l):
+        l[i] = tmpl.replace(ident, pfx)
+
+
+def fix_tmpl_refs_re(l, regex, repl):
+    for i, tmpl in enumerate(l):
+        l[i] = re.sub(regex, repl, tmpl)
+
+
+class LoadTemplate(object):
+    '''
+    Load a template and its dependencies, generate a
+    configuration file which should be relatively easy and
+    straightforward to parse.
+    '''
+    edit_instructions = '''# Edit instructions:
+#
+# Add content only at the end of lines starting with '%%'.
+# Only add content, don't remove or replace anything.
+# The parameters following '%required' are not optional,
+# unlike those following '%optional'.
+# You may also add comments for future reference.'''
+    no_more_edit = '''# Don't edit anything below this line.'''
+
+    def __init__(self, name):
+        self.name = name
+        self.all_pre_gen = []
+        self.all_post_gen = []
+        self.all_pfx = []
+
+    def new_pfx(self, name):
+        i = 1
+        pfx = name
+        while pfx in self.all_pfx:
+            pfx = "%s_%d" % (name, i)
+            i += 1
+        self.all_pfx.append(pfx)
+        return pfx
+
+    def generate(self):
+        return '\n'.join(
+            ["# Configuration: %s" % self.name,
+             '',
+             self.edit_instructions,
+             '',
+             '\n'.join(self.all_pre_gen),
+             self.no_more_edit,
+             '',
+             '%generate',
+             '\n'.join(self.all_post_gen)])
+
+    def write_config(self, name):
+        try:
+            f = open("%s/%s" % (userdir.CRMCONF_DIR, name), "w")
+        except IOError as msg:
+            logger.error("open: %s", msg)
+            return False
+        print(self.generate(), file=f)
+        f.close()
+        return True
+
+    def load_template(self, tmpl):
+        try:
+            l = open(os.path.join(config.path.sharedir, 'templates', tmpl)).read().split('\n')
+        except IOError as msg:
+            logger.error("open: %s", msg)
+            return ''
+        if not validate_template(l):
+            return ''
+        logger.info("pulling in template %s", tmpl)
+        g = l.index('%generate')
+        pre_gen = l[0:g]
+        post_gen = l[g+1:]
+        name = get_var(pre_gen, '%name')
+        for s in l[0:g]:
+            if s.startswith('%depends_on'):
+                a = s.split()
+                if len(a) != 2:
+                    logger.warning("%s: wrong usage", s)
+                    continue
+                tmpl_id = a[1]
+                tmpl_pfx = self.load_template(a[1])
+                if tmpl_pfx:
+                    fix_tmpl_refs(post_gen, '%'+tmpl_id, '%'+tmpl_pfx)
+        pfx = self.new_pfx(name)
+        fix_tmpl_refs(post_gen, '%_:', '%'+pfx+':')
+        # replace remaining %_, it may be useful at times
+        fix_tmpl_refs(post_gen, '%_', pfx)
+        v_idx = pre_gen.index('%required') or pre_gen.index('%optional')
+        pre_gen.insert(v_idx, '%pfx ' + pfx)
+        self.all_pre_gen += pre_gen
+        self.all_post_gen += post_gen
+        return pfx
+
+    def post_process(self, params):
+        pfx_re = '(%s)' % '|'.join(self.all_pfx)
+        for n in params:
+            fix_tmpl_refs(self.all_pre_gen, '%% '+n, "%% "+n+"  "+params[n])
+        fix_tmpl_refs_re(self.all_post_gen,
+                         '%' + pfx_re + '([^:]|$)', r'\1\2')
+        # process %if ... [%else] ... %fi
+        rmidx_l = []
+        if_seq = False
+        outcome = False  # unnecessary, but to appease lints
+        for i in range(len(self.all_post_gen)):
+            s = self.all_post_gen[i]
+            if if_seq:
+                a = s.split()
+                if len(a) >= 1 and a[0] == '%fi':
+                    if_seq = False
+                    rmidx_l.append(i)
+                elif len(a) >= 1 and a[0] == '%else':
+                    outcome = not outcome
+                    rmidx_l.append(i)
+                else:
+                    if not outcome:
+                        rmidx_l.append(i)
+                continue
+            if not s:
+                continue
+            a = s.split()
+            if len(a) == 2 and a[0] == '%if':
+                outcome = not a[1].startswith('%')  # not replaced -> false
+                if_seq = True
+                rmidx_l.append(i)
+        rmidx_l.reverse()
+        for i in rmidx_l:
+            del self.all_post_gen[i]
+
+# vim:ts=4:sw=4:et: