import pytest
import aiohttp
from aiohttp import web
import mazegen

paths = ('/static',) + tuple(f'/dynamic/{n:X}' for n in range(15))
checks = 'walls','exits','solvable'

def assert_maze(m):
    """Checks for valid maze.
    Converts cells to integers to ease other checks.
    """
    assert type(m) is list
    assert len(m) == 7
    for row in m:
        assert type(row) is str
        assert len(row) == 7
        for cell in row:
            assert cell in '0123456789abcdefABCDEF'
    return tuple(tuple(int(c,16) for c in row) for row in m)

def assert_walls(m):
    """Checks that left walls match right walls and top match bottom"""
    for i in range(7):
        for j in range(6):
            assert bool(m[i][j] & 4) == bool(m[i][j+1] & 1)
            assert bool(m[j][i] & 2) == bool(m[j+1][i] & 8)

def assert_exits(m, num):
    assert bool(m[3][0]&1) == bool(num&1)
    assert bool(m[6][3]&2) == bool(num&2)
    assert bool(m[3][6]&4) == bool(num&4)
    assert bool(m[0][3]&8) == bool(num&8)

def find_path(m, p1, p2):
    visited = {p1}
    queue = [p1]
    while len(queue) > 0:
        p = queue.pop()
        y,x = p
        n = m[y][x]
        for nm,dx,dy in (1,-1,0), (2,0,+1), (4,+1,0), (8,0,-1):
            if x+dx < 0 or x+dx > 6 or y+dy < 0 or y+dy > 6: continue
            if not (n & nm):
                q = (y+dy,x+dx)
                if q == p2: return True
                if q not in visited:
                    visited.add(q)
                    queue.append(q)
    return False

def assert_solvable(m, num):
    points = [(3,0),(6,3),(3,6),(0,3)]
    seg = [points[i] for i in range(4) if (num & (1<<i)) == 0]
    for i in range(1,len(seg)):
        assert find_path(m, seg[i-1], seg[i])

@pytest.mark.parametrize('path,rule', [(a,b) for a in paths for b in checks])
async def test_maze(aiohttp_client, path, rule):
    if path[-2] == '/':
        num = int(path[-1], 16)
    else:
        num = 0
    app = web.Application()
    app.add_routes(mazegen.routes)
    client = await aiohttp_client(app)
    resp = await client.get(path)
    assert resp.status == 200
    assert resp.content_type == 'application/json'
    maze = await resp.json()
    m = assert_maze(maze)
    if rule == 'walls':
        assert_walls(m)
    if rule == 'exits':
        assert_exits(m, num)
    if rule == 'solvable':
        assert_walls(m)
        assert_solvable(m, num)

@pytest.mark.parametrize('path', paths[1:])
async def test_dynamic(aiohttp_client, path):
    num = int(path[-1], 16)
    app = web.Application()
    app.add_routes(mazegen.routes)
    client = await aiohttp_client(app)
    answers = set()
    for i in range(20):
        resp = await client.get(path)
        assert resp.status == 200
        assert resp.content_type == 'application/json'
        maze = await resp.json()
        m = assert_maze(maze)
        assert_walls(m)
        assert_exits(m, num)
        assert_solvable(m, num)
        answers.add(m)
    assert len(answers) > 10

@pytest.mark.parametrize('path', paths[:1])
async def test_static(aiohttp_client, path):
    num = 0
    app = web.Application()
    app.add_routes(mazegen.routes)
    client = await aiohttp_client(app)
    answers = set()
    provided = {
        assert_maze(["988088c","1000004","1000004","0000000","1000004","1000004","3220226"]), # blank
        assert_maze(["98a0a8c","1494b04","1430e14","0280820","1e575d5","1e1c575","3a202a6"]), # CS 340
        assert_maze(["9a8088c","5b02024","5b49494","0a02020","5b4d1e5","1e571e5","3a282a6"]) # Err 500
    }
    for i in range(20):
        resp = await client.get(path)
        assert resp.status == 200
        assert resp.content_type == 'application/json'
        maze = await resp.json()
        m = assert_maze(maze)
        assert m not in provided, "Don't use the mazes that we provided as examples"
        assert_walls(m)
        assert_exits(m, num)
        assert_solvable(m, num)
        answers.add(m)
    assert len(answers) == 1