#!/usr/bin/env python3
import json
import os
import pwd
import time


class Wilty():

    def __init__(self):
        self.save_dir = ".botany"
        self.plant_file = "_plant_data.json"
        self.visit_file = "visitors.json"
        self.plants = {}
        self.loadData()

    def convertTS(self, ts):
        """Convert a timestamp in seconds to a legible format, e.g. 12d 12h
        12m."""
        days = int(ts / 86400)
        hours = int((ts % 86400) / 3600)
        mins = round(((ts % 86400) % 3600) / 60)
        return str(days) + "d " + str(hours) + "h " + str(mins) + "m"

    def getUsers(self):
        """Load usernames into the plants dictionary as keys."""
        sys_users = pwd.getpwall()
        for u in sys_users:
            if os.path.exists("/home/" + u.pw_name + "/" + self.save_dir):
                self.plants[u.pw_name] = {}

    def checkPlant(self, user):
        """Given the username, calculates the last time since the user's
        plant was watered, estimates whether it is dead and updates the plants
        dictionary."""
        # Get last visitor timestamp and check if later than user's
        visitor_ts = 0
        if self.plants[user]["visitors"] != []:
            visitor_ts = self.plants[user]["visitors"][-1]["timestamp"]
        watered = max(self.plants[user]["last_watered"], visitor_ts)
        time_since = int(time.time()) - watered
        self.plants[user]["time_since"] = time_since
        # >432000 (5 days) = dead plant
        if time_since > 432000:
            self.plants[user]["is_dead"] = True
        self.plants[user]["time_since_fmt"] = self.convertTS(time_since)

    def loadData(self):
        """Load plant and visitor data into plants dictionary."""
        self.getUsers()
        for u in self.plants:
            sv_dir = "/home/" + u + "/" + self.save_dir + "/"
            # Get plant data
            if os.access(sv_dir + u + self.plant_file, os.R_OK):
                with open(sv_dir + u + self.plant_file) as plant_fh:
                    plant_json = plant_fh.read()
                self.plants[u] = json.loads(plant_json)
                self.plants[u]["allow_query"] = True
            else:
                self.plants[u]["allow_query"] = False
            # Get visitor data
            if os.access(sv_dir + self.visit_file, os.R_OK) and \
                    os.access(sv_dir + self.visit_file, os.W_OK):
                with open(sv_dir + self.visit_file) as visit_fh:
                    visit_json = visit_fh.read()
                self.plants[u]["visitors"] = json.loads(visit_json)
                self.plants[u]["allow_visit"] = True
            else:
                self.plants[u]["allow_visit"] = False
                self.plants[u]["visitors"] = []
            # Update plant watered state if plant data is readable
            if self.plants[u]["allow_query"]:
                self.checkPlant(u)

    def listLivePlants(self, *args, **kwargs):
        """List living plants open to visitors."""
        sort_l = []
        for p in self.plants:
            if self.plants[p]["allow_query"] and \
                    self.plants[p]["allow_visit"] and \
                    not self.plants[p]["is_dead"]:
                sort_l.append((p, self.plants[p]["description"].split()[-1], \
                        self.plants[p]["time_since_fmt"], \
                        self.plants[p]["time_since"]))
        # Sort by column
        column = kwargs.get("sort", "")
        if column == "user":
            sort_l.sort(key=lambda c: c[0])
        elif column == "plant":
            sort_l.sort(key=lambda c: c[1])
        else:
            sort_l.sort(key=lambda c: c[3], reverse=True)
        # Format output
        border = "-" * 47
        print(border)
        print("{:<20s}{:<15s}{:<15s}".format("User", "Plant", "Last Watered"))
        print(border)
        for i in sort_l:
            print("{:<20s}{:<15s}{:<15s}".format(i[0], i[1], i[2]))
        print(border)


instance = Wilty()
instance.listLivePlants()