# start the server
import asyncio
import subprocess
from functools import partial

import pytest
import pytest_asyncio
from typing import List
from deltas import Delete, Equal, Insert, wikitext_split
from mwpersistence import Token
from wiki_diff_matcher import WikiDiffMatcher


@pytest_asyncio.fixture(scope="module")
async def start_stop_server():
    proc = await asyncio.create_subprocess_exec("php", "-S", "127.0.0.1:8000",
                                                "wikidiff2_api.php",
                                                stdout=subprocess.PIPE,
                                                stderr=subprocess.PIPE)
    yield proc
    stdout, stderr = await proc.communicate()
    print(stdout.encode())
    print(stderr.encode())
    proc.terminate()


def assert_equal_enough(tokens:List[Token], rev):
    # the tokens exclude newlines
    # we allow extra whitespace at the beginning or end
    assert ''.join([str(t) for t in tokens]).strip() == rev.replace('\n','').strip()


def assert_correct_equal_section(ops, expected_equal_lines, expected_equal_tokens):
    n_equal_lines = 0
    last_b2 = max(ops[0].b1, 0)
    initial_equal_tokens = 0
    first_unequal_token = None
    for op in ops:
        if not isinstance(op, Equal):
            if isinstance(op, Insert):
                first_unequal_token = op.b1
            else:
                first_unequal_token = op.a1
            break
        n_equal_lines += 1
        initial_equal_tokens += op.b2 - last_b2
        last_b2 = op.b2

    if expected_equal_lines == 1:
        first_unequal_token = op.b2 + 1

    # if the last line is an equal
    if first_unequal_token is None:
        first_unequal_token = ops[-1].b2

    
    assert n_equal_lines == expected_equal_lines
    # check that there are no gaps and the number is as expected
    assert initial_equal_tokens == last_b2 - ops[0].b1 == first_unequal_token - ops[0].b1 == expected_equal_tokens
    return last_b2

def test_equality():
    rev1 = open("test/test_diff_revisions/1285792388").read()
    # whitespace is added because exact identity reverts do not result in diffs.
    matcher = WikiDiffMatcher([rev1,rev1 + " "])
    diff_processor = matcher.processor()
    ops, a, b = diff_processor.process(rev1)
    ops, a, b = diff_processor.process(rev1 + " ")
    assert len(ops) == 129
    for op in ops[:-1]:
       assert isinstance(op, Equal)

    # note that the whitespace token does not result in a token according to wikitext_split
    # compare the tokens based on the diffs to the baseline
    # whitespace differences are allowed
    assert_equal_enough(b, rev1)

def test_highlight_range():
    rev1 = open("test/test_diff_revisions/1295229484_rangeedit0").read()
    rev2 = open("test/test_diff_revisions/1295229484_rangeedit1").read()
    matcher = WikiDiffMatcher([rev1,rev2])
    diff_processor = matcher.processor()
    diff_processor.process(rev1)
    ops, a, b = diff_processor.process(rev2)
    assert_equal_enough(a, rev1)
    assert_equal_enough(b, rev2)


def test_delete():
    rev1 = open("test/test_diff_revisions/1295229484").read()
    rev2 = open("test/test_diff_revisions/1295229484_delete").read()

    # whitespace is added because exact identity reverts do not result in diffs.
    matcher = WikiDiffMatcher([rev1,rev2])
    diff_processor = matcher.processor()
    diff_processor.process(rev1)
    ops, a, b = diff_processor.process(rev2)
    assert_equal_enough(b, rev2)
    assert_equal_enough(a, rev1)

    initial_equal_tokens = 0
    first_nondelete_token = None
    n_deletes = 0
    n_deleted_tokens = 0
    last_b2 = initial_equal_tokens

    initial_equal_lines = 2
    initial_equal_tokens = 12
    last_b2 = assert_correct_equal_section(ops,
                                           expected_equal_lines=initial_equal_lines,
                                           expected_equal_tokens=initial_equal_tokens)
    first_noninsert_token = initial_equal_tokens
    

    for op in ops[initial_equal_lines:]:
        if not isinstance(op, Delete):
            first_nondelete_token = op.a1
            break
        n_deletes += 1
        n_deleted_tokens += op.a2 - last_b2
        last_b2 = op.a2
        
    assert n_deletes == 2
    assert n_deleted_tokens == last_b2 - initial_equal_tokens == first_nondelete_token - initial_equal_tokens == 316

    last_b2 = assert_correct_equal_section(ops[initial_equal_lines + n_deletes:],
                                           expected_equal_lines=126,
                                           expected_equal_tokens=9323)




# first lets test that we properly build the operations. 
# then we can test if the state seems to work as intended.
def test_addition():
    rev1 = open("test/test_diff_revisions/1285792388").read()
    rev2 = open("test/test_diff_revisions/1295229484").read()
    matcher = WikiDiffMatcher([rev1,rev2])
    diff_processor = matcher.processor()

    # note that a and b are constructed from the diffs.
    # so they reflect the state of the text according to the diff processor
    ops, a, b = diff_processor.process(rev1)

    for op in ops:
       assert isinstance(op, Insert)

    assert_equal_enough(b, rev1)
    
    diff_processor.previous_text = rev1

    ops, a, b = diff_processor.process(rev2)
    assert_equal_enough(a, rev1)
    assert_equal_enough(b, rev2)
    ops = list(ops)
    initial_equal_lines = 128
    initial_equal_tokens = 9359
    last_b2 = assert_correct_equal_section(ops,
                                           expected_equal_lines=initial_equal_lines,
                                           expected_equal_tokens=initial_equal_tokens)
    first_noninsert_token = None
    n_inserts = 0
    n_inserted_tokens = 0
    last_b2 = initial_equal_tokens
    for op in ops[initial_equal_lines:]:
        n_inserts += 1
        n_inserted_tokens += op.b2 - last_b2
        last_b2 = op.b2

    assert n_inserted_tokens == last_b2 - initial_equal_tokens == 292
    assert n_inserts == 2