# -*- coding: utf-8 -*-
#
# PgDataDiff - compare tables, print data differencies
#
# Copyright (c) 2011  Radek Brich <radek.brich@devl.cz>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.


from collections import OrderedDict

from pgtoolkit import pgbrowser
from pgtoolkit.highlight import *


class DiffData:
    COLORS = {
        '+' : BOLD | GREEN,
        '-' : BOLD | RED,
        '*' : BOLD | YELLOW,
        'V' : BOLD | WHITE}
    
    def __init__(self, change, cols1, cols2, id=None):
        self.change = change
        self.cols1 = cols1
        self.cols2 = cols2
        self.id = id
    
    def format(self):
        out = []
        
        out.append(highlight(1, self.COLORS[self.change]))
        out.extend([self.change, ' '])
        
        out.extend(self._format_changes())
        
        out.append(highlight(0))
        
        return ''.join(out)

    def format_patch(self, table):
        method = {
            '+' : self._format_insert,
            '-' : self._format_delete,
            '*' : self._format_update}
        
        return method[self.change](table)

    def _format_changes(self):
        if self.cols1 and not self.cols2:
            return [', '.join([self._format_value_del(*x) for x in self.cols1.items()])]
        if not self.cols1 and self.cols2:
            return [', '.join([self._format_value_add(*x) for x in self.cols2.items()])]
        
        items = []
        for i in range(len(self.cols1)):
            items.append((
                list(self.cols1.keys())[i],
                list(self.cols1.values())[i],
                list(self.cols2.values())[i]))
            
        return [', '.join([self._format_value_change(*x) for x in items])]

    def _format_value_del(self, k, v):
        fs = (highlight(1, self.COLORS['-']) + '{}: ' + highlight(0) + '{}')
        return fs.format(k, v)

    def _format_value_add(self, k, v):
        fs = (highlight(1, self.COLORS['+']) + '{}: ' + highlight(0) + 
            highlight(1, self.COLORS['V']) + '{}' + highlight(0))
        return fs.format(k, v)

    def _format_value_change(self, k, v1, v2):
        fs = (highlight(1, self.COLORS['*']) + '{}: ' + highlight(0) + 
            '{} ▶ ' +
            highlight(1, self.COLORS['V']) + '{}' + highlight(0))
        return fs.format(k, v1, v2)

    def _format_insert(self, table):
        out = ['INSERT INTO ', table, ' (']
        out.append(', '.join(self.cols2.keys()))
        out.append(') VALUES (')
        out.append(', '.join(self.cols2.values()))
        out.append(');')
        return ''.join(out)
    
    def _format_delete(self, table):
        out = ['DELETE FROM ', table]
        out.extend(self._format_where()) 
        return ''.join(out)
    
    def _format_update(self, table):
        out = ['UPDATE ', table, ' SET ']
        out.append(', '.join([self._format_set(*x) for x in self.cols2.items()]))
        out.extend(self._format_where())
        return ''.join(out)

    def _format_set(self, k, v):
        return '{} = {}'.format(k, v)

    def _format_where(self):
        out = [' WHERE ']
        out.extend([self.id[0], ' = '])
        out.append(self.id[1])
        out.append(';')
        return out

class PgDataDiff:
    def __init__(self, conn1, conn2):
        self.allowcolor = False
        self.conn1 = conn1
        self.conn2 = conn2
        self.fulltable1 = None
        self.fulltable2 = None
    
    def settable1(self, table, schema='public'):
        self.schema1 = schema
        self.table1 = table
        self.fulltable1 = '"' + schema + '"."'+ table + '"'
        
    def settable2(self, table, schema='public'):
        self.schema2 = schema
        self.table2 = table
        self.fulltable2 = '"' + schema + '"."'+ table + '"'
    
    def iter_diff(self):
        '''Return differencies between data of two tables.
        
        Yields one line at the time.
        
        '''
        curs1, curs2 = self._select()
        
        row1 = curs1.fetchone_adapted()
        row2 = curs2.fetchone_adapted()
        
        while True:
            if row1 is None and row2 is None:
                break
            diff = self._compare_row(row1, row2)
            
            if diff:
                yield diff
            
                if diff.change == '-':
                    row1 = curs1.fetchone_adapted()
                    continue
                if diff.change == '+':
                    row2 = curs2.fetchone_adapted()
                    continue
            # change == '*' or not diff
            row1 = curs1.fetchone_adapted()
            row2 = curs2.fetchone_adapted()
    
    def print_diff(self):
        '''Print differencies between data of two tables.
        
        The output is in human readable form.
        
        Set allowcolor=True of PgDataDiff instance to get colored output.
        
        '''
        for ln in self.iter_diff():
            print(ln.format())
    
    def print_patch(self):
        '''Print SQL script usable as patch for destination table.
        
        Supports INSERT, DELETE and UPDATE operations.
        
        '''
        for ln in self.iter_diff():
            print(ln.format_patch(self.fulltable2))

    def _select(self):
        browser = pgbrowser.PgBrowser(self.conn1)
        columns = browser.list_columns(schema=self.schema1, table=self.table1)
        columns_sel = ', '.join(['"' + x['name'] + '"' for x in columns])
        self.colnames = [x['name'] for x in columns]
        
        query1 = 'SELECT ' + columns_sel + ' FROM ' + self.fulltable1 + ' ORDER BY 1;'
        query2 = 'SELECT ' + columns_sel + ' FROM ' + self.fulltable2 + ' ORDER BY 1;'
        
        curs1 = self.conn1.cursor()
        curs2 = self.conn2.cursor()
        
        curs1.execute(query1)
        curs2.execute(query2)
        
        return curs1, curs2

    def _compare_data(self, row1, row2):
        cols1 = OrderedDict()
        cols2 = OrderedDict()
        for i in range(len(row1)):
            if row1[i] != row2[i]:
                cols1[self.colnames[i]] = row1[i]
                cols2[self.colnames[i]] = row2[i]
        if cols1:
            id = (self.colnames[0], row1[0])
            return DiffData('*', cols1, cols2, id=id)
        
        return None
    
    def _compare_row(self, row1, row2):
        if row2 is None:
            cols1 = OrderedDict(zip(self.colnames, row1))
            return DiffData('-', cols1, None)
        if row1 is None:
            cols2 = OrderedDict(zip(self.colnames, row2))
            return DiffData('+', None, cols2)
        
        if row1[0] < row2[0]:
            cols1 = OrderedDict(zip(self.colnames, row1))
            id = (self.colnames[0], row1[0])
            return DiffData('-', cols1, None, id=id)
        if row1[0] > row2[0]:
            cols2 = OrderedDict(zip(self.colnames, row2))
            return DiffData('+', None, cols2)
        
        return self._compare_data(row1, row2)