# -*- coding: utf-8 -*-
 
from datetime import datetime
import sys
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.font_manager as font_manager
import matplotlib.dates as mdates
import logging
from pylab import *
mpl.rcParams['font.sans-serif'] = ['SimHei']
 
class Gantt(object):
    #顏色色標：參考http://colorbrewer2.org/
    RdYlGr = ['#d73027', '#f46d43', '#fdae61','#fee08b', '#ffffbf', '#d9ef8b','#a6d96a', '#66bd63', '#1a9850']
 
    POS_START = 1.0
    POS_STEP = 0.5
 
    def __init__(self, tasks):
        self._fig = plt.figure(figsize=(15,10))
        self._ax = self._fig.add_axes([0.1, 0.1, .75, .5])
 
        self.tasks = tasks[::-1]  # 倒序
 
    def _format_date(self, date_string):
        try:
            date = datetime.datetime.strptime(date_string, '%Y-%m-%d %H:%M:%S')  # 將日期字符串轉換成datetime類型
        except ValueError as err:
            logging.error("String '{0}' can not be converted to datetime object: {1}"
                   .format(date_string, err))
            sys.exit(-1)
        mpl_date = mdates.date2num(date)  # 得到日期類型的時間戳
        return mpl_date
 
    def _plot_bars(self):
        i = 0
        for task in self.tasks:
            start = self._format_date(task['start'])  # 獲取任務開始時間的時間戳
            end = self._format_date(task['end'])      # 獲取任務結束時間的時間戳
            bottom = (i * Gantt.POS_STEP) + Gantt.POS_START
            width = end - start    # 柱子的寬度
            self._ax.barh(bottom, width, left=start, height=0.3,align='center', label=task['label'],color = Gantt.RdYlGr[i%len(Gantt.RdYlGr)])
            i += 1
 
    def _configure_yaxis(self):
        task_labels = [t['label'] for t in self.tasks]   # 所有的刻度文本標簽
        pos = self._positions(len(task_labels))          # 素有的刻度值
        ylocs = self._ax.set_yticks(pos)                 # 設置y軸刻度線
        ylabels = self._ax.set_yticklabels(task_labels)  # 設置y軸刻度標簽
        plt.setp(ylabels, size='medium')                 # 設置y軸刻度標簽屬性（中號字）
 
    def _configure_xaxis(self):
        self._ax.xaxis_date()     # 使用時間軸
        rule = mdates.rrulewrapper(mdates.WEEKLY, interval=1)   # 生成時間生成器（每周1個值，從周日開始）
        loc = mdates.RRuleLocator(rule)                         # 生成時間刻度
        formatter = mdates.DateFormatter("%m/%d")               # 生成時間格式
 
        self._ax.xaxis.set_major_locator(loc)          # 設置主刻度
        self._ax.xaxis.set_major_formatter(formatter)  # 設置主刻度標簽格式
        xlabels = self._ax.get_xticklabels()           # 獲取刻度標簽對象
        plt.setp(xlabels, rotation=70, fontsize=10)    # 設置刻度標簽對象的屬性（30度旋轉，字體大小10）
 
    def _configure_figure(self):
        self._configure_xaxis()
        self._configure_yaxis()
 
        self._ax.grid(True, axis='x',color='gray')
        self._set_legend()
        self._fig.autofmt_xdate()
 
    def _set_legend(self):
        font = font_manager.FontProperties(size='small')
        self._ax.legend(loc='upper right', prop=font)
 
    def _positions(self, count):
        end = count * Gantt.POS_STEP + Gantt.POS_START
        pos = np.arange(Gantt.POS_START, end, Gantt.POS_STEP)
        return pos
    
    def show(self):
        self._plot_bars()
        self._configure_figure()
        plt.show()

if __name__ == '__main__':
    TEST_DATA = (
                 { 'label': '項目調研', 'start':'2019-02-01 12:00:00', 'end': '2019-03-15 18:00:00'},
                 { 'label': '項目準備', 'start':'2019-02-15 09:00:00', 'end': '2019-04-09 12:00:00'},
                 { 'label': '制定方案', 'start':'2019-04-10 12:00:00', 'end': '2019-05-30 18:00:00'},
                 { 'label': '項目實施', 'start':'2019-05-01 09:00:00', 'end': '2019-08-31 13:00:00'},
                 { 'label': '項目培訓', 'start':'2019-07-01 09:00:00', 'end': '2019-09-21 13:00:00'},
                 { 'label': '項目驗收', 'start':'2019-09-22 09:00:00', 'end': '2019-10-22 13:00:00'},
                 { 'label': '項目竣工', 'start':'2019-10-23 09:00:00', 'end': '2019-11-23 13:00:00'},
                )
    
    gantt = Gantt(TEST_DATA)
    plt.xlabel('項目日期')
    plt.ylabel('項目進度')
    plt.title('項目進度甘特圖')
    plt.figure(figsize=(10,10),dpi=150)
    gantt.show()