# microcms.py - tiny file based CMS for static web sites
# Copyright (c) 2009 Niall McCarroll  
# Distributed under the MIT/X11 License (http://www.mccarroll.net/snippets/license.txt)

# functionality:
#   expand ./.. in HTML files to the relative path to the top level directory 
#   transform HTML content using plugins

# usage:
#   cd <root-directory-of-site>
#   python microcms.py 
   
import sys
import os
import re
import copy
import codecs
from tinplate import tinplate

rootdir = None
plugins = {}
plugin_consumers = {}
plugin_processors = {}

def loadplugins():
    global plugins
    global plugin_processors
    global plugin_consumers
    pluginsdir = os.path.join(os.path.split(sys.argv[0])[0],'plugins')
    for f in os.listdir(pluginsdir):
        if f.endswith(".py"):
            mname = os.path.splitext(f)[0]    
            try:
                plugin = __import__("plugins",globals(),locals(),[mname],-1)
                plugins[mname] = plugin
            except Exception, ex:
                print f+":"+str(ex)
                pass

    for plugin in plugins:
        try:
            processfn = getattr(getattr(plugins[plugin],plugin),'process')
            plugin_processors[plugin] = processfn
            print "Loaded processor function from module:"+plugin
        except Exception, ex:
            pass 
        try:
            consumefn = getattr(getattr(plugins[plugin],plugin),'consume')
            plugin_consumers[plugin] = consumefn
            print "Loaded consumer function from module:"+plugin
        except Exception, ex:
            pass        

filter = ['.chtml']

pat1 = re.compile(r'(.*)<microcms([^>]*)>(.*)')
pat2 = re.compile(r'\s*([a-zA-Z_]*)\s*=\s*\"([^\"]*)\"(.*)')

def parse_microcms(line):
    mat = pat1.match(line)
    if mat:
        attrs = {}
        attrtxt = mat.group(2)
        mat2 = pat2.match(attrtxt)
        while mat2:
            aname = mat2.group(1)
            avalue = mat2.group(2)
            attrtxt = mat2.group(3)
            mat2 = pat2.match(attrtxt)
            attrs[aname] = avalue
        return (mat.group(1),attrs,mat.group(3))
    else:
        return None

class cmsdirectory:

    def __init__(self,name,files,directories):
        self.name = name
        self.files = files
        self.directories = directories
        self.indexfile = None
        for d in self.directories:
            d.parentdir = self
        for f in self.files:
            f.parentdir = self
            if os.path.split(f.path)[1] == "index.chtml":
                self.indexfile = f
        self.parentdir = None

    def depth(self):
        depth = 0
        d = self.parentdir
        while d != None:
            d = d.parentdir
            depth += 1
            
        return depth
        
    def getName(self):
        return self.name
             

class cmsfile:

    def __init__(self,path,outpath):
        self.path = path
        self.outpath = outpath
        self.metadata = None
        self.parentdir = None
       
    def depth(self):
        if self.parentdir:
            return self.parentdir.depth()
        else:
            return 0
        
def expand_env(line,env):
    for k in env:
        pos = 0
        while True:
            pos = line.find("$"+k,pos)
            if pos == -1:
                break
            if pos == 0 or line[pos-1] != "$":
                line = line[:pos]+env[k]+line[pos+len(k)+1:]
                pos += len(env[k])
            else:
                line = line[:pos]+line[pos+1:]
                pos += len(k)   
    return line 
                
def rewritecontents(content,cfile,original_env,extpath=None):
    lines = content.split("\n")
    
    result = ''    
    
    for line in lines:
        
        env = copy.copy(original_env)

        rootpath = "."
        for x in xrange(0,cfile.parentdir.depth()):
            rootpath = os.path.join(rootpath,"..")
        env["root"] = rootpath
        
        line = expand_env(line,env)
        microcms_cmd = parse_microcms(line)
        if microcms_cmd:
            pre = microcms_cmd[0]
            attrs = microcms_cmd[1]
            if "path" in attrs and extpath:
                attrs["path"] = os.path.join(extpath,attrs["path"])
            post = microcms_cmd[2]
            func = attrs["function"]
            
            inc = ''
            
            # search for a matching plugin and invoke it
            global plugin_processors
            if func in plugin_processors:
                inc = plugin_processors[func](cfile,attrs)
            else:
                inc += "microcms error: could not load plugin: "+func
            epath = None
            if "path" in attrs:
                epath = os.path.split(attrs["path"])[0]
                
            # rewrite the content returned from the plugin
            for attr in attrs:
                env[attr] = attrs[attr]
                    
            result += pre+rewritecontents(inc,cfile,env,epath)+post        
        else:
            result += line
        
        result += "\n"    
   
    return result

def rewritefile(path,cfile,original_env):
    print path
    fin = codecs.open(path, encoding='utf-8', mode='r')
    content = fin.read()
    fin.close()
    return rewritecontents(content,cfile,original_env)
    
def rewrite(cfile):
    fout = codecs.open(cfile.outpath, encoding='utf-8', mode='w')
    fout.write(rewritefile(cfile.path,cfile,{}))
    fout.close()  
    
def scanfiles(path,norecurse=False):
    
    directories = []
    files = []
    dname = ""
    pathsplit = os.path.split(path)
    if len(pathsplit)>1:
        dname = pathsplit[1]
 
    if not norecurse:
        for f in os.listdir(path):
            fpath = os.path.join(path,f)
            if os.path.isdir(fpath):
                subdir = scanfiles(fpath)
                if subdir != None:
                    directories.append(subdir)

    for f in os.listdir(path):
        fpath = os.path.join(path,f)
        
        if fpath.startswith("./"):
            fpath = fpath[2:]
        if os.path.isfile(fpath):
            (root,ext) = os.path.splitext(fpath)
            outpath = root+".html"
           
            if ext in filter:
                relpath = os.path.join(os.path.split(path)[1],os.path.split(outpath)[1])
                
                print "processing:"+fpath
                cfile = cmsfile(fpath,outpath)
                files.append(cfile)

                fin = open(fpath,"r")
                contents = fin.read()
                for func in sorted(plugin_consumers):
                    plugin_consumers[func](cfile,contents)
                
              
    if len(files)>0 or len(directories)>0:
        return cmsdirectory(dname,files,directories)
    else:
        return None

def processfiles(directory):
    
    for f in directory.files:
        rewrite(f)

    for d in directory.directories:
        processfiles(d)

if __name__ == '__main__':
    norecurse = False
    if len(sys.argv)>1 and sys.argv[1] == "-norecurse":
        norecurse = True
    loadplugins()
    rootdir = scanfiles(".",norecurse)
    processfiles(rootdir)