from __future__ import with_statement

import MySQLdb as mysql
import glob
import difflib
import os
import time
import sys
import string

##        Usage:  vcs.py <function>
##
##        You must manually create the database 'vcs'
##
##        Function:
##        ---------
##
##            install          -   install the table/s required for the operation of vcs
##            commit           -   forcefully update all files
##            start_service [#]-   start periodic update service.  Where # is defined, update ever # seconds
##                                 default: 300 secs
##            update <file>    -   update <file>
##            regress <file>   -   revert <file> or all

db = mysql.connect(user='root', passwd='', db='vcs').cursor()

def get_project(name = None):
    if not name:
        proj_file = glob.glob('*.PROJ')
        if len(proj_file) == 0:
            proj_name = raw_input('\nPlease enter a name for the project: ')
            if proj_name:
                with open('%s.PROJ' % proj_name, 'w') as f:
                    f.write(proj_name)
            else:
                sys.stderr.write('Error: Must enter a name for the project!!')
                sys.exit(1)
        else:
            return proj_file[0]
    else:
        with open('%s.PROJ' % name, 'w') as f:
            f.write(name)

project = get_project()
    
def install():
    sys.stdout.write('\nInstalling tables...\n')
    sys.stdout.write('Installing FILES table\n')
    sql = r'''CREATE TABLE files ( id INT NOT NULL AUTO_INCREMENT PRIMARY KEY, project VARCHAR(255), name VARCHAR(255), last_chg VARCHAR(24), data LONGTEXT ) '''
    db.execute(sql)
    sys.stdout.write('Done!\n')

def update(f):
    with open(f, 'r') as data:
        buffer = data.read()

    t = time.time()
    #print 'INSERT INTO files VALUES (NULL, "%s", "%s", "%s")' % (f, t, buffer)
    db.execute('INSERT INTO files VALUES (0, "%s", "%s", "%s", "%s")' % (project, f, t, buffer))
            
def start_service(period=300):
    sys.stdout.write('\nStarting VCS periodic update service...\n')
    files = glob.glob('*.py')
    diff = {}

    for f in files:
        diff[f] = os.stat(f)

    while(1):
        
        files = glob.glob('*.py')
        num_files = len(files)
        count = 0

        sys.stdout.write('\nExecuting periodic update\n')
        sys.stdout.write('Time: %s\n' % time.strftime('%H:%M:%S'))
        sys.stdout.write('Checking %s files...\n' % num_files)
        
        for f in files:
            if f is 'vcs.py': continue
            if diff[f] <> os.stat(f):
                update(f)
                sys.stdout.write('Updating %s\n' % f)
                count += 1

        sys.stdout.write('Finished!\n\nUpdated %s files\n' % count)

        time.sleep(period)

def commit():

    sys.stdout.write('\nInitiating update all...\n\n')
    files = glob.glob('*.py')
    count = 0
    for f in files:
        if f == 'vcs.py': continue
        sys.stdout.write('Updating %s\n' % f)
        update(f)
        count += 1
    sys.stdout.write('\nUpdated %s files\n' % count)

def revert_one(name):
    sql = 'SELECT * FROM files WHERE name="%s" AND project="%s" ORDER BY last_chg DESC LIMIT 1' % (name, project)
    db.execute(sql)
    latest = db.fetchone()
    if not latest:
        sys.stderr.write('Warning: Database contains no file %s!!\n' % name)
        #sys.exit(1)
        return
    os.remove(name)
    with open(name, 'w') as f:
        f.write(latest[4])
    sys.stdout.write('File: %s reverted to database version stored: %s\n' % (name, time.strftime("%a, %d %b %Y %H:%M:%S", time.gmtime(float(latest[3])))))

def regress(name=None):
    if name:
        name = name if name.endswith('.py') else name + '.py'
        revert_one(name)
    else:
        files = glob.glob('*.py')
        for f in files:
            if f == 'vcs.py': continue
            revert_one(f)
        
def start_project():

    commit()
    #other init stuff as it comes up

   
if __name__ == '__main__':

    arg = sys.argv
    if arg[0] == 'python':
        arg = arg[1:]

    if len(arg) == 1:
        sys.stderr.write('\nUsage: python vcs <function>\n')
        sys.exit(1)

    if arg[1] in dir():
        if len(arg) > 2:
            exec('%s("%s")' % (arg[1], string.join(arg[2:],',')))
            
        else:
            exec('%s()' % arg[1])
    else:
        sys.stderr.write('\nUsage: python vcs <function>\n')
        sys.exit(1)