#!/usr/bin/python2.6
# coding: utf-8
from __future__ import with_statement
import os
try:
    import json
except ImportError:
    import simplejson as json
from StringIO import StringIO
from whoosh.index import open_dir
from whoosh.qparser import QueryParser
import whoosh.searching as searching
import whoosh.analysis as analysis
import whoosh.highlight as highlight
import whoosh.query as query
import flask
import pyPdf
import werkzeug
import subprocess
from compat import str_format

app = flask.Flask("booksearch")

index_book = open_dir(u"index", u"book")
index_metadata = open_dir(u"index", u"metadata")

@app.route("/")
def do_index():
    return flask.redirect(flask.url_for("do_search",term=""))

@app.route("/book/file/<int:docnum>")
def do_book_file(docnum):
    with index_metadata.reader() as reader:
        document = reader.stored_fields(docnum)
        r = werkzeug.Response(open(document['path'], "r"), mimetype="application/pdf",)
        r.headers.add('Content-Disposition', 'attachment', 
            filename=os.path.basename(document['path']))
        return r

   
def pdf_to_image(filepath, page, size):
    if not type(size) == int or size < 1 or size > 2000:
        size = 260

    density = 60 + 0.15 * size
    app.logger.debug( str_format("Convert PDF to image page={page} size={size} density={density} filepath={filepath}", page=page, size=size, density=density, filepath=filepath ))

    def generator(process, input):
        input.seek(0)
        while not process.stdin.closed:
            stdout, stderr = process.communicate(input.read())
            if stdout:
                yield stdout
    pdffile = StringIO()
    page = pyPdf.PdfFileReader(file(filepath, 'r')).getPage(page)
    out = pyPdf.PdfFileWriter()
    out.addPage(page)
    out.write(pdffile)
    process = subprocess.Popen(["/usr/bin/convert", "-density", str(density), "-resize", str(size), "pdf:-", "jpeg:-"],
        stdin=subprocess.PIPE, stdout=subprocess.PIPE)
    return werkzeug.Response(generator(process,pdffile), mimetype="image/jpeg")

@app.route("/page/image/<int:docnum>", methods=["GET"])
@app.route("/page/image/<int:docnum>/<int:size>", methods=["GET"])
def do_page_image(docnum,size=260):
    with index_book.reader() as reader:
        document = reader.stored_fields(docnum)
        page = document['pagenumber'] - 1
        return pdf_to_image(document['path'], page, size=size)
    
 
@app.route("/book/frontpage/<int:docnum>", methods=["GET"])
def do_book_frontpage(docnum):
    with index_metadata.reader() as reader:
        document = reader.stored_fields(docnum)
        return pdf_to_image(document['path'], 0, 260)
 
@app.route("/page/file/<int:docnum>", methods=["GET"])
def do_page_file(docnum):
    with index_book.reader() as reader:
        document = reader.stored_fields(docnum)
        filepath = document['path']
        page = document['pagenumber'] - 1
    app.logger.debug(str_format("Extract page={page} from filepath={filepath}", page=page, filepath=filepath))
    inputfile = pyPdf.PdfFileReader(file(filepath, 'r'))
    pdfpage = inputfile.getPage(page)
    outbuf = StringIO()
    outfile = pyPdf.PdfFileWriter()
    outfile.addPage(pdfpage)
    outfile.write(outbuf)
    outbuf.seek(0)
    r = werkzeug.Response(outbuf, mimetype="application/pdf")
    client_filename = os.path.basename(filepath)[:-3]
    client_filename += str_format(u".Page-{page}.pdf", page=page)
    r.headers.add('Content-Disposition', 'attachment', filename=client_filename)
    return r

class MyHtmlFormatter(highlight.HtmlFormatter):
    def _format_fragment(self, text, fragment, seen):
        text = unicode( flask.Markup.escape(text) )
        return highlight.HtmlFormatter._format_fragment(self, text, fragment, seen)

@app.route("/excerpt/<int:docnum>/<path:term>", methods=["GET"])
def excerpt(docnum, term):
    def generator(q):
        for result in searcher.search(q, limit=1, sortedby="pagenumber"):
            terms = [ text for fieldname, text in q.all_terms()
                if fieldname == "content" ]
            excerpt = highlight.highlight(result.get("content"), 
                        terms,
                        analysis.StandardAnalyzer(),
                        highlight.ContextFragmenter(terms, maxchars=400, charsbefore=40, charsafter=40), #highlight.SentenceFragmenter(maxchars=500),
                        MyHtmlFormatter())
     
            yield json.dumps( { 'pagenumber':result.get("pagenumber"),
                                'excerpt':excerpt,
                                'docnum':result.docnum} )

    with index_book.reader() as reader:
        document = reader.stored_fields(docnum)
    q = QueryParser("content").parse(term)
    terms = [ text for fieldname, text in q.all_terms()
        if fieldname == "content" ]
    excerpt = highlight.highlight(document['content'],
                terms,
                analysis.StandardAnalyzer(),
                highlight.SimpleFragmenter(),
                MyHtmlFormatter())
    return unicode( excerpt )

@app.route("/search/<path:term>",methods=["GET"])
@app.route("/search/", methods=["GET"])
def do_search(term=None):
    if not term:
        return flask.render_template('search.html', objects=[], term="")

    searcher = index_book.searcher()
    query = QueryParser("content").parse(term)
    facets = searching.Facets.from_field(searcher, "path")
    results = searcher.search(query, limit=None, sortedby="pagenumber")
    categories = facets.categorize(results)
    searcher.close()

    books = {}
    with index_book.reader() as reader:
        for book in categories.items():
            filepath = book[0]
            with index_metadata.searcher() as searcher:
                docnum = searcher.document_number(path=filepath)
            with index_metadata.reader() as reader2:
                title = reader2.stored_fields(docnum).get('title')
            books[docnum] = {
                'matches' : [],
                'title':title,
                'filename' : os.path.basename(filepath),
            }
            for match in book[1]:
                pagenumber = reader.stored_fields(match[0])['pagenumber']
                match = (match[0], match[1], pagenumber)
                books[docnum]['matches'].append(match)

    return flask.render_template('search.html',
                            books=books, 
                            term=term)

def log_response(sender, response):
    sender.logger.debug('Request context is about to close down.  '
                            'Response: %s', response)
if __name__ == "__main__":
    app.debug = True
    app.run(host="0.0.0.0")