# -*- coding: utf-8 -*-

import sys
sys.path.append('/home/users/jpa/remtemp/lib/python2.3/site-packages/')

import rrdtool
import time
import os
import base64, struct
import tempfile
import zlib

# Stand-alone functions in other module
from graphutils import *

rrdpath = "/home/users/jpa/remtemp/rrds"

class RRDObject:
    def getid(self, suffix = None):
        '''Returns rrdtool compatible id for the object, possibly with a suffix'''
        r = base64.b16encode(struct.pack("q", id(self)))
        if suffix is not None:
            r += '_' + str(suffix)

        return r


class RRDDef(RRDObject):
    '''Data source definition'''
    def __init__(self, graph, name, quantity, cf, start = None, end = None, history = 0):
        self.graph = graph
        
        self.name = name
        self.path = os.path.join(rrdpath, os.path.basename(name)) + ".rrd"
        self.quantity = quantity
        self.cf = cf
        
        if start is not None:
            self.start = start
        else:
            self.start = graph.start
        
        if end is not None:
            self.end = end
        else:
            self.end = graph.end
        
        self.history = history

    def getcommands(self):
        '''Return list of commands for rrdtool'''

        r = []
        r.append("DEF:%s=%s:%s:%s:start=%d:end=%d" %
            (self.getid(), self.path, self.quantity, self.cf, self.start, self.end))

        if self.history:
            r.append("SHIFT:%s:%d" % (self.getid(), self.history))

        return r

class RRDLine(RRDObject):
    '''A graph line or area'''
    def __init__(self, graph, rrddef, color, description = None, writeinfo = False):
        '''Defid is the id of the DEF: clause.
        Color is a string of hexadecimal definition, eg. "FF9999".
        Description is a string that will be displayed in legend, or None to hide legend.
        If writeinfo is true, average, max, min and last will be written in legend.
        '''
        
        self.graph = graph
        self.units = graph.units
        self.style = graph.defaultstyle # Style is either 'LINE1', 'LINE2', 'LINE3' or 'AREA'.
        
        self.rrddef = rrddef
        
        self.color = color
        self.description = description
        self.writeinfo = writeinfo

    def getcommands(self):
        '''Return list of commands for rrdtool'''

        defid = self.rrddef.getid()
        
        if self.writeinfo and self.description is not None:
            description = self.description + "." * (self.graph.infomargin - len(unicode(self.description, 'utf-8')))

        r = []
        if self.description is not None:
            r.append("%s:%s#%s:%s" % (self.style, defid, self.color, description))
        else:
            r.append("%s:%s#%s" % (self.style, defid, self.color))

        if self.writeinfo:
            infounits = self.units.replace('%', '%%')
            infounits += ' ' * (5 - len(infounits))
            r.append("GPRINT:%s:MIN:Min %%4.1lf %s" % (defid, infounits))
            r.append("GPRINT:%s:MAX:\tMax %%4.1lf %s" % (defid, infounits))
            r.append("GPRINT:%s:AVERAGE:\tKa. %%4.1lf %s" % (defid, infounits))
            r.append("GPRINT:%s:LAST:\tNyt %%4.1lf %s" % (defid, infounits))

        r.append("COMMENT:\\n")

        return r

class Graph:
    mimetypes = {'PNG' : 'image/png',
                 'SVG' : 'image/svg',
                 'EPS' : 'application/postscript',
                 'PDF' : 'application/pdf'}
    
    def __init__(self, format, title, units = '°C'):
        self.format = format

        self.title = title
        self.units = units
        
        self.defaultstyle = 'LINE1'

        self.width = 800
        self.height = 400

        self.defs = []
        self.lines = []
        
        self.infomargin = 40 # Horizontal position to print info at

        self.compress = False

        self.end = int(time.time())
        self.start = self.end - 86400

    def isvector(self):
        return self.format in ['SVG', 'EPS', 'PDF']

    def setsmall(self):
        self.width = 650
        self.height = 250
        self.infomargin = 30

    def hasinfo(self):
        for l in self.lines:
            if l.writeinfo:
                return True
        return False

    def getcommands(self, file):
        r = []

        r.append(file)
        r.append('--slope-mode')
        r += ['--tabwidth', '30']
        r += ['--imgformat', self.format]
        r += ['--start', str(int(self.start))]
        r += ['--end', str(int(self.end))]
        r += ['--title', self.title]
        r += ['--vertical-label', self.units]
        r += ['--width', str(self.width), '--height', str(self.height)]

        if self.hasinfo():
            r.append("COMMENT:\\n")

        for d in self.defs + self.lines:
            r += d.getcommands()

        return r

    def graph(self):
        '''Create a graph and return data in a string'''
        file = tempfile.NamedTemporaryFile()

        args = self.getcommands(file.name)
        rrdtool.graph(*args)

        r = file.read()
        file.close()

        if self.compress:
            r = zlib.compress(r, 9)

        return r

    def cgigraph(self):
        '''Create a graph and print appropiate Content-type header and the data'''
        data = self.graph()
        
        print 'Content-type:', Graph.mimetypes[self.format]
        print
        print data

    def newRRDDef(self, *args, **kwargs):
        '''Creates a new RRDDef, adds it to the graph and returns it'''
        d = RRDDef(self, *args, **kwargs)
        self.defs.append(d)
        return d

    def newRRDLine(self, *args, **kwargs):
        '''Creates a new RRDLine, adds it to the graph and returns it'''
        d = RRDLine(self, *args, **kwargs)
        self.lines.append(d)
        return d
    
    def applycgiparams(self):
        import cgi
        f = cgi.FieldStorage()
        
        if f.has_key('start'):
            self.start = parsetime(f['start'].value)
        
        if f.has_key('end'):
            self.end = parsetime(f['end'].value)
        
        if f.has_key('width'):
            self.width = int(f['width'].value)
        
        if f.has_key('height'):
            self.width = int(f['height'].value)
        
        if f.has_key('small'):
            self.setsmall()
        
        if f.has_key('format'):
            format = f['format'].value.upper()
            if format in Graph.mimetypes.keys():
                self.format = format
        
        if f.has_key('compress'):
            self.compress = True