# -*- 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

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)