import watcher
import annotate
import filters
import searchengine
import parser
import traceback
import cgi
from cStringIO import StringIO
import itertools
import gzip

class Reporter(object):

    def render_file(self, filenames, watchers, pipeline):
        if isinstance(filenames, (str, unicode)):
            filenames = [filenames]
        open_files = []
        log_readers = []
        for filename in filenames:
            if filename.endswith('.gz'):
                f = gzip.open(filename, 'rb')
                f.name = filename
            else:
                f = open(filename, 'rb')
            open_files.append(f)
            log_readers.append(parser.Parser(f))
        log_reader = itertools.chain(*log_readers)
        try:
            result = self.render(log_reader, watchers, pipeline)
            return result
        finally:
            for f in open_files:
                f.close()

    def render(self, log_reader, watchers, pipeline):
        w = watcher.pass_through(watchers)
        pipeline.append(w)
        new_iter = iter(log_reader)
        for pipe in pipeline:
            new_iter = iter(pipe.iterlog(new_iter))
        for value in new_iter:
            # The watchers will handle the actual accumulation
            pass
        reports = []
        for w in watchers:
            try:
                report = w.report()
            except:
                out = StringIO()
                traceback.print_exc(file=out)
                report = '<pre>%s</pre>' % cgi.escape(out.getvalue())
            if not report:
                continue
            reports.append({
                'name': w.name,
                'title': w.title,
                'report': report})
        return self.format_reports(reports)
        
    def format_reports(self, reports):
        page = []
        indexes = []
        for report in reports:
            indexes.append('<a href="#%s">%s</a>'
                           % (report['name'], report['title']))
            page.append('<h2 id="%s">%s</h2>'
                        % (report['name'], report['title']))
            page.append('<div>%s</div>' % report['report'])
        return '<br>'.join(indexes) + '<hr noshade>' + '\n'.join(page)

provides = {}

def scan(module):
    for name in dir(module):
        value = getattr(module, name)
        if not hasattr(value, 'provides'):
            continue
        for name in value.provides:
            provides[name] = value

scan(watcher)
scan(annotate)
scan(filters)
scan(searchengine)

for normal_attr in 'client ident authuser utim method url proto status bytes referer agent'.split():
    provides[normal_attr] = None

def setup_stack(watchers):
    has = []
    pipeline = []
    for w in watchers:
        has.extend(w.provides)
    for w in watchers:
        assert not isinstance(w.require, str), (
            "Bad require: %s" % w)
        for req in w.require:
            add_require(req, has, pipeline)
    return watchers, pipeline

def add_require(require_name, has, pipeline):
    if require_name in has:
        return
    need = provides[require_name]
    if need is None:
        has.append(require_name)
        return
    need = need()
    has.append(require_name)
    pipeline.append(need)
    assert not isinstance(need.require, str), (
        "Bad require: %s" % need)
    for req in need.require:
        add_require(req, has, pipeline)