# -*- coding: utf-8 -*-
##############################################################################
#
#    OpenERP, Open Source Management Solution
#    Copyright (C) 2014-Today OpenERP SA (<http://www.openerp.com>).
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU Affero General Public License as
#    published by the Free Software Foundation, either version 3 of the
#    License, or (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU Affero General Public License for more details.
#
#    You should have received a copy of the GNU Affero General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
##############################################################################

from openerp.osv.osv import except_osv
from openerp.addons.web import http
from openerp.tools.translate import _
from openerp.addons.web.http import request

import time
import base64
import logging
import tempfile
import lxml.html
import subprocess
import simplejson
try:
    import cStringIO as StringIO
except ImportError:
    import StringIO

from pyPdf import PdfFileWriter, PdfFileReader
from werkzeug.test import Client
from werkzeug.wrappers import BaseResponse
from werkzeug.datastructures import Headers


_logger = logging.getLogger(__name__)


class Report(http.Controller):

    @http.route(['/report/<reportname>/<docids>'], type='http', auth='user', website=True, multilang=True)
    def report_html(self, reportname, docids, **kwargs):
        """This is the generic route for QWeb reports. It is used for reports
        which do not need to preprocess the data (i.e. reports that just display
        fields of a record).

        It is given a ~fully qualified report name, for instance 'account.report_invoice'.
        Based on it, we know the module concerned and the name of the template. With the
        name of the template, we will make a search on the ir.actions.reports.xml table and
        get the record associated to finally know the model this template refers to.

        There is a way to declare the report (in module_report(s).xml) that you must respect:
            id="action_report_model"
            model="module.model"  # To know which model the report refers to
            string="Invoices"
            report_type="qweb-pdf"  # or qweb-html
            name="module.template_name"
            file="module.template_name"

        If you don't want your report to be listed under the print button, just add
        'menu=False'.
        """
        ids = [int(i) for i in docids.split(',')]
        ids = list(set(ids))
        report = self._get_report_from_name(reportname)
        report_obj = request.registry[report.model]
        docs = report_obj.browse(request.cr, request.uid, ids, context=request.context)

        docargs = {
            'doc_ids': ids,
            'doc_model': report.model,
            'docs': docs,
        }

        return request.registry['report'].render(request.cr, request.uid, [], report.report_file,
                                                 docargs, context=request.context)

    @http.route(['/report/pdf/<path:path>'], type='http', auth="user", website=True)
    def report_pdf(self, path=None, landscape=False, **post):
        cr, uid, context = request.cr, request.uid, request.context

        # Get the report we are working on.
        # Pattern is /report/module.reportname(?a=1)
        reportname_in_path = path.split('/')[1].split('?')[0]
        report = self._get_report_from_name(reportname_in_path)

        # Check attachment_use field. If set to true and an existing pdf is already saved, return
        # this one now. If not, mark save it.
        save_in_attachment = {}

        if report.attachment_use is True:
            # Get the record ids we are working on.
            path_ids = [int(i) for i in path.split('/')[2].split('?')[0].split(',')]

            save_in_attachment['model'] = report.model
            save_in_attachment['loaded_documents'] = {}

            for path_id in path_ids:
                obj = request.registry[report.model].browse(cr, uid, path_id)
                filename = eval(report.attachment, {'object': obj, 'time': time})

                if filename is False:  # May be false if, for instance, the record is in draft state
                    continue
                else:
                    alreadyindb = [('datas_fname', '=', filename),
                                   ('res_model', '=', report.model),
                                   ('res_id', '=', path_id)]

                    attach_ids = request.registry['ir.attachment'].search(cr, uid, alreadyindb)
                    if attach_ids:
                        # Add the loaded pdf in the loaded_documents list
                        pdf = request.registry['ir.attachment'].browse(cr, uid, attach_ids[0]).datas
                        pdf = base64.decodestring(pdf)
                        save_in_attachment['loaded_documents'][path_id] = pdf
                        _logger.info('The PDF document %s was loaded from the database' % filename)
                    else:
                        # Mark current document to be saved
                        save_in_attachment[path_id] = filename

        # Get the paperformat associated to the report, if there is.
        if not report.paperformat_id:
            user = request.registry['res.users'].browse(cr, uid, uid, context=context)
            paperformat = user.company_id.paperformat_id
        else:
            paperformat = report.paperformat_id

        # Get the html report.
        html = self._get_url_content('/' + path, post)

        # Get some css and script in order to build a minimal html page for the report.
        # This page will later be sent to wkhtmltopdf.
        css = self._get_url_content('/report/static/src/css/reset.min.css')
        css += self._get_url_content('/web/static/lib/bootstrap/css/bootstrap.css')
        css += self._get_url_content('/website/static/src/css/website.css')
        subst = self._get_url_content('/report/static/src/js/subst.js')

        headerhtml = []
        contenthtml = []
        footerhtml = []
        minimalhtml = """
<html style="height: 0mm;">
    <head>
        <style type='text/css'>{0}</style>
        <script type='text/javascript'>{1}</script>
    </head>
    <body class="container" onload='subst()'>
        {2}
    </body>
</html>"""

        # The retrieved html report must be simplified. We convert it into a xml tree
        # via lxml in order to extract header, footer and all reportcontent.
        try:
            root = lxml.html.fromstring(html)

            for node in root.xpath("//html/head/style"):
                css += node.text

            for node in root.xpath("//div[@class='header']"):
                body = lxml.html.tostring(node)
                header = minimalhtml.format(css, subst, body)
                headerhtml.append(header)

            for node in root.xpath("//div[@class='footer']"):
                body = lxml.html.tostring(node)
                footer = minimalhtml.format(css, subst, body)
                footerhtml.append(footer)

            for node in root.xpath("//div[@class='page']"):
                # Previously, we marked some reports to be saved in attachment via their ids, so we
                # must set a relation between report ids and reportcontent. We use the QWeb
                # branding in order to do so: searching after a node having a data-oe-model
                # attribute with the value of the current report model and read its oe-id attribute
                oemodelnode = node.find(".//*[@data-oe-model='" + report.model + "']")
                if oemodelnode is not None:
                    reportid = oemodelnode.get('data-oe-id', False)
                    if reportid is not False:
                        reportid = int(reportid)
                else:
                    reportid = False

                body = lxml.html.tostring(node)
                reportcontent = minimalhtml.format(css, '', body)
                contenthtml.append(tuple([reportid, reportcontent]))

        except lxml.etree.XMLSyntaxError:
            contenthtml = []
            contenthtml.append(html)
            save_in_attachment = {}  # Don't save this potentially malformed document

        # Get paperformat arguments set in the root html tag. They are prioritized over
        # paperformat-record arguments.
        specific_paperformat_args = {}
        for attribute in root.items():
            if attribute[0].startswith('data-report-'):
                specific_paperformat_args[attribute[0]] = attribute[1]

        # Execute wkhtmltopdf process.
        pdf = self._generate_wkhtml_pdf(headerhtml, footerhtml, contenthtml, landscape,
                                        paperformat, specific_paperformat_args, save_in_attachment)

        return self._make_pdf_response(pdf)

    def _get_url_content(self, url, post=None):
        """Resolve an internal webpage url and return its content with the help of
        werkzeug.test.client.

        :param url: string representing the url to resolve
        :param post: a dict representing the query string
        :returns: a tuple str(html), int(statuscode)
        """
        # Rebuilding the query string.
        if post:
            url += '?'
            url += '&'.join('%s=%s' % (k, v) for (k, v) in post.iteritems())

        # We have to pass the current headers in order to see the report.
        reqheaders = Headers(request.httprequest.headers)
        response = Client(request.httprequest.app, BaseResponse).get(url, headers=reqheaders,
                                                                     follow_redirects=True)
        content = response.data

        try:
            content = content.decode('utf-8')
        except UnicodeDecodeError:
            pass

        return content

    def _generate_wkhtml_pdf(self, headers, footers, bodies, landscape,
                             paperformat, spec_paperformat_args=None, save_in_attachment=None):
        """Execute wkhtmltopdf as a subprocess in order to convert html given in input into a pdf
        document.

        :param header: list of string containing the headers
        :param footer: list of string containing the footers
        :param bodies: list of string containing the reports
        :param landscape: boolean to force the pdf to be rendered under a landscape format
        :param paperformat: ir.actions.report.paperformat to generate the wkhtmltopf arguments
        :param specific_paperformat_args: dict of prioritized paperformat arguments
        :param save_in_attachment: dict of reports to save/load in/from the db
        :returns: Content of the pdf as a string
        """
        command = ['wkhtmltopdf-0.12']
        tmp_dir = tempfile.gettempdir()

        # Display arguments
        command_args = []

        if paperformat:
            command_args.extend(self._build_wkhtmltopdf_args(paperformat, spec_paperformat_args))

        if landscape and '--orientation' in command_args:
            command_args_copy = list(command_args)
            for index, elem in enumerate(command_args_copy):
                if elem == '--orientation':
                    del command_args[index]
                    del command_args[index]
                    command_args.extend(['--orientation', 'landscape'])
        elif landscape and not '--orientation' in command_args:
            command_args.extend(['--orientation', 'landscape'])

        pdfdocuments = []
        # HTML to PDF thanks to WKhtmltopdf
        for index, reporthtml in enumerate(bodies):
            command_arg_local = []
            pdfreport = tempfile.NamedTemporaryFile(suffix='.pdf', prefix='report.tmp.',
                                                    mode='w+b')
            # Directly load the document if we have it
            if save_in_attachment and save_in_attachment['loaded_documents'].get(reporthtml[0]):
                pdfreport.write(save_in_attachment['loaded_documents'].get(reporthtml[0]))
                pdfreport.seek(0)
                pdfdocuments.append(pdfreport)
                continue

            # Header stuff
            if headers:
                head_file = tempfile.NamedTemporaryFile(suffix='.html', prefix='report.header.tmp.',
                                                        dir=tmp_dir, mode='w+')
                head_file.write(headers[index])
                head_file.seek(0)
                command_arg_local.extend(['--header-html', head_file.name])

            # Footer stuff
            if footers:
                foot_file = tempfile.NamedTemporaryFile(suffix='.html', prefix='report.footer.tmp.',
                                                        dir=tmp_dir, mode='w+')
                foot_file.write(footers[index])
                foot_file.seek(0)
                command_arg_local.extend(['--footer-html', foot_file.name])

            # Body stuff
            content_file = tempfile.NamedTemporaryFile(suffix='.html', prefix='report.body.tmp.',
                                                       dir=tmp_dir, mode='w+')
            content_file.write(reporthtml[1])
            content_file.seek(0)

            try:
                wkhtmltopdf = command + command_args + command_arg_local
                wkhtmltopdf += [content_file.name] + [pdfreport.name]

                process = subprocess.Popen(wkhtmltopdf, stdout=subprocess.PIPE,
                                           stderr=subprocess.PIPE)
                out, err = process.communicate()

                if process.returncode != 0:
                    raise except_osv(_('Report (PDF)'),
                                     _('wkhtmltopdf-patched failed with error code = %s. '
                                       'Message: %s') % (str(process.returncode), err))

                # Save the pdf in attachment if marked
                if reporthtml[0] is not False and save_in_attachment.get(reporthtml[0]):
                    attachment = {
                        'name': save_in_attachment.get(reporthtml[0]),
                        'datas': base64.encodestring(pdfreport.read()),
                        'datas_fname': save_in_attachment.get(reporthtml[0]),
                        'res_model': save_in_attachment.get('model'),
                        'res_id': reporthtml[0],
                    }
                    request.registry['ir.attachment'].create(request.cr, request.uid, attachment)
                    _logger.info('The PDF document %s is now saved in the '
                                 'database' % attachment['name'])

                pdfreport.seek(0)
                pdfdocuments.append(pdfreport)

                if headers:
                    head_file.close()
                if footers:
                    foot_file.close()
            except:
                raise

        # Get and return the full pdf
        if len(pdfdocuments) == 1:
            content = pdfdocuments[0].read()
            pdfdocuments[0].close()
        else:
            content = self._merge_pdf(pdfdocuments)

        return content

    def _build_wkhtmltopdf_args(self, paperformat, specific_paperformat_args=None):
        """Build arguments understandable by wkhtmltopdf from an ir.actions.report.paperformat
        record.

        :paperformat: ir.actions.report.paperformat record associated to a document
        :specific_paperformat_args: a dict containing prioritized wkhtmltopdf arguments
        :returns: list of string containing the wkhtmltopdf arguments
        """
        command_args = []
        if paperformat.format and paperformat.format != 'custom':
            command_args.extend(['--page-size', paperformat.format])

        if paperformat.page_height and paperformat.page_width and paperformat.format == 'custom':
            command_args.extend(['--page-width', str(paperformat.page_width) + 'in'])
            command_args.extend(['--page-height', str(paperformat.page_height) + 'in'])

        if specific_paperformat_args and specific_paperformat_args['data-report-margin-top']:
            command_args.extend(['--margin-top',
                                 str(specific_paperformat_args['data-report-margin-top'])])
        else:
            command_args.extend(['--margin-top', str(paperformat.margin_top)])

        if paperformat.margin_left:
            command_args.extend(['--margin-left', str(paperformat.margin_left)])
        if paperformat.margin_bottom:
            command_args.extend(['--margin-bottom', str(paperformat.margin_bottom)])
        if paperformat.margin_right:
            command_args.extend(['--margin-right', str(paperformat.margin_right)])
        if paperformat.orientation:
            command_args.extend(['--orientation', str(paperformat.orientation)])
        if paperformat.header_spacing:
            command_args.extend(['--header-spacing', str(paperformat.header_spacing)])
        if paperformat.header_line:
            command_args.extend(['--header-line'])
        if paperformat.dpi:
            command_args.extend(['--dpi', str(paperformat.dpi)])

        return command_args

    def _get_report_from_name(self, report_name):
        """Get the first record of ir.actions.report.xml having the argument as value for
        the field report_name.
        """
        report_obj = request.registry['ir.actions.report.xml']
        qwebtypes = ['qweb-pdf', 'qweb-html']

        idreport = report_obj.search(request.cr, request.uid,
                                     [('report_type', 'in', qwebtypes),
                                      ('report_name', '=', report_name)])

        report = report_obj.browse(request.cr, request.uid, idreport[0],
                                   context=request.context)
        return report

    def _make_pdf_response(self, pdf):
        """Make a request response for a PDF file with correct http headers.

        :param pdf: content of a pdf in a string
        :returns: request response for a pdf document
        """
        pdfhttpheaders = [('Content-Type', 'application/pdf'),
                          ('Content-Length', len(pdf))]
        return request.make_response(pdf, headers=pdfhttpheaders)

    def _merge_pdf(self, documents):
        """Merge PDF files into one.

        :param documents: list of pdf files
        :returns: string containing the merged pdf
        """
        writer = PdfFileWriter()
        for document in documents:
            reader = PdfFileReader(file(document.name, "rb"))
            for page in range(0, reader.getNumPages()):
                writer.addPage(reader.getPage(page))
            document.close()
        merged = StringIO.StringIO()
        writer.write(merged)
        merged.seek(0)
        content = merged.read()
        merged.close()
        return content

    @http.route('/report/downloadpdf/', type='http', auth="user")
    def report_pdf_attachment(self, data, token):
        """This function is only used by 'qwebactionmanager.js' in order to trigger the download of
        a pdf report.

        :param data: The JSON.stringified report internal url
        :returns: Response with a filetoken cookie and an attachment header
        """
        url = simplejson.loads(data)
        pdf = self._get_url_content(url)
        response = self._make_pdf_response(pdf)
        response.set_cookie('fileToken', token)
        response.headers.add('Content-Disposition', 'attachment; filename=report.pdf;')
        return response