import numpy as np
from collections import OrderedDict
import os.path

def init_db():
	import sqlalchemy as db
	_verbose = False #True
	engine = db.create_engine('postgresql://hpc@hawk-monitor4:5432/coe_mon', echo=_verbose)
	conn = engine.connect()
	return conn

def init_query(jobid, interval):
	import sqlalchemy as db
	query_string = """with job as (
	select job_id, starttime, endtime, nodes from jobs where job_id='{jobid}.hawk-pbs5'
),
node_series as(
	select n.name, scmcavg.id as series_id from nodes n 
		inner join (select * from label where key='node') l on n.id = l.value::int
		inner join series_cmc_power_racktraynodepoweravg scmcavg on l.id = scmcavg.labels[(
			select pos from  label_key_position 
				where metric_category= 'cmc_power' 
				and metric_name = 'RackTrayNodePowerAvg'  
				and key = 'node'
			)]
	where n.id = any((select nodes from job)::int[])
)
select a.time, a.value, ns.name from (
	select 
		time_bucket(extract ('epoch' from '{interval} seconds'::interval)::int*1000, cmcavg.ts) as time, 
		cmcavg.series_id::varchar,
		avg(cmcavg.val) AS value
	from cmc_power_racktraynodepoweravg cmcavg
where
	ts  <= (select endtime from job) 
	and ts >= (select starttime from job)
	and series_id = Any(select series_id from node_series)
group by time, cmcavg.series_id order by time desc) a
inner join node_series ns on a.series_id::int = ns.series_id;
"""
	return db.text(query_string.format(jobid=jobid, interval=interval))

def db_to_list(connection, query):
	return connection.execute(query).fetchall()

def db_to_pf(connection, query):
	return pd.read_sql(query, con=connection)

class Power:
	def __init__(self, nodes):
		self.nodes = nodes
		self.epochs = OrderedDict()
		self.first_ts = None
		self.last_ts = None

	def insert_epoch(self, ts, values):
		self.epochs[ts] = values
		if not self.first_ts:
			self.first_ts = ts
		self.last_ts = ts

	@classmethod
	def from_list(cls, data):
		"""Assumes data is a list of tuples (timestamp, value, node)"""
		nodes = list(set([line[2] for line in data]))
		cls = Power(nodes)
	
		#times = list(set([line[0] for line in data]))

		# for now ignore order to nodes
		values = {}
		for l in data:
			ts = l[0]
			if ts not in values:
				values[ts] = []
			# node = l[1]
			power = l[1]
			values[ts].append(power)

		epochs = sorted(values.keys())
		for epoch in epochs:
			cls.insert_epoch(epoch, values[epoch])
		
		return cls
	
	def header(self):
		hd  = "# all timestamp have unit miliseconds since unix epoch\n"
		hd += "# all power values have unit Watt\n"
		hd += "timestamp,delta_t,head_node_power,avg_node_power,median_node_power,min_node_power,max_node_power,std_dev_node_power"
		# add node names here instead
		hd += ",NO_NODE_NAMES_YET\n"
		return hd

	@staticmethod
	def summarize_values(val):
		values = np.asarray(val)
		head = values[0]
		min, max = values.min(), values.max()
		avg, stddev = values.mean(), values.std()
		median = np.median(values)
		return head, avg, median, min, max, stddev

	
	@staticmethod
	def summarize_time(ts):
		return ts, -1
	
	@staticmethod
	def summarize_epoch(epoch):
		ts, values = epoch
		return Power.summarize_time(ts) \
				+ Power.summarize_values(values)
				# + values
	
	@staticmethod
	def pretty_print(args):
		return ",".join(str(a) for a in args) + '\n'


	def body(self):
		_body = ""
		for epoch in self.epochs.items():
			_body += Power.pretty_print(self.summarize_epoch(epoch))
		return _body

	def filename(self, jobid):
		fname = "detailed_power_{jobid}.hawk-pbs5.{first}-{last}.csv".format(
			jobid=jobid, first=self.first_ts, last=self.last_ts
		)
		return fname
	

	def to_file(self, jobid):
		"""Dumps power data to file. Returns filename is succesfull and None if unsucessfull."""
		fname = self.filename(jobid)
		if os.path.exists(fname):
			print("Error: cowardly refusing to overwrite file ", fname)
			return None

		try:
			with open(fname, "w+") as f:
				f.write(self.header())
				f.write(self.body())
		except IOError:
			print("Error: could not write to file ", filename)
			fname = None

		return fname


if __name__ == "__main__":
	conn = init_db()
	jobid = "2260215"
	interval = 5
	query = init_query(jobid, interval)

	all_list = db_to_list(conn, query)
	#all_df = db_to_df(conn, query)

	power = Power.from_list(all_list) # , jobid, interval)
	print("#epochs", len(power.epochs))
	
	print(power.header())
	
	epochs_iter = iter(power.epochs.items())
	ts, values = next(epochs_iter)
	print(ts, values)
	print('time:', power.summarize_time(ts))
	print('values:', power.summarize_values(values))
	print('epoch:', power.pretty_print(power.summarize_epoch((ts, values))))
	print("filename: ", power.to_file(jobid))