#!/usr/bin/env python
"""
simple example script for running and testing notebooks.

Usage: `ipnbdoctest.py foo.ipynb [bar.ipynb [...]]`

Each cell is submitted to the kernel, and the outputs are compared
with those stored in the notebook.
"""

from __future__ import print_function

import os,sys,time
import base64
import re
from difflib import unified_diff as diff

from collections import defaultdict
try:
    from queue import Empty
except ImportError:
    print('Python 3.x is needed to run this script.')
    sys.exit(77)

import imp
try:
    imp.find_module('IPython')
except:
    print('IPython is needed to run this script.')
    sys.exit(77)

try:
    from IPython.kernel import KernelManager
except ImportError:
    from IPython.zmq.blockingkernelmanager import BlockingKernelManager as KernelManager

from IPython.nbformat.current import reads, NotebookNode


def compare_png(a64, b64):
    """compare two b64 PNGs (incomplete)"""
    try:
        import Image
    except ImportError:
        pass
    adata = base64.decodestring(a64)
    bdata = base64.decodestring(b64)
    return True

def sanitize(s):
    """sanitize a string for comparison.

    fix universal newlines, strip trailing newlines, and normalize likely
    random values (memory addresses and UUIDs)
    """
    if not isinstance(s, str):
        return s
    # normalize newline:
    s = s.replace('\r\n', '\n')

    # ignore trailing newlines (but not space)
    s = s.rstrip('\n')

    # normalize hex addresses:
    s = re.sub(r'0x[a-f0-9]+', '0xFFFFFFFF', s)

    # normalize UUIDs:
    s = re.sub(r'[a-f0-9]{8}(\-[a-f0-9]{4}){3}\-[a-f0-9]{12}', 'U-U-I-D', s)

    return s


def consolidate_outputs(outputs):
    """consolidate outputs into a summary dict (incomplete)"""
    data = defaultdict(list)
    data['stdout'] = ''
    data['stderr'] = ''

    for out in outputs:
        if out.type == 'stream':
            data[out.stream] += out.text
        elif out.type == 'pyerr':
            data['pyerr'] = dict(ename=out.ename, evalue=out.evalue)
        else:
            for key in ('png', 'svg', 'latex', 'html',
                        'javascript', 'text', 'jpeg',):
                if key in out:
                    data[key].append(out[key])
    return data


def compare_outputs(test, ref, skip_cmp=('png', 'traceback',
                                         'latex', 'prompt_number')):
    for key in ref:
        if key not in test:
            print("missing key: %s != %s" % (test.keys(), ref.keys()))
            return False
        elif key not in skip_cmp and sanitize(test[key]) != sanitize(ref[key]):
            print("mismatch %s:" % key)
            exp = ref[key]
            eff = test[key]
            if exp[:-1] != '\n':
                exp += '\n'
            if eff[:-1] != '\n':
                eff += '\n'
            print(''.join(diff(exp.splitlines(1), eff.splitlines(1),
                               fromfile='expected', tofile='effective')))
            return False
    return True


def run_cell(shell, iopub, cell):
    # print cell.input
    shell.execute(cell.input)
    # wait for finish, maximum 20s
    shell.get_msg(timeout=20)
    outs = []

    while True:
        try:
            msg = iopub.get_msg(timeout=0.2)
        except Empty:
            break
        msg_type = msg['msg_type']
        if msg_type in ('status', 'pyin'):
            continue
        elif msg_type == 'clear_output':
            outs = []
            continue

        content = msg['content']
        # print msg_type, content
        out = NotebookNode(output_type=msg_type)

        if msg_type == 'stream':
            out.stream = content['name']
            out.text = content['data']
        elif msg_type in ('display_data', 'pyout'):
            out['metadata'] = content['metadata']
            for mime, data in content['data'].items():
                attr = mime.split('/')[-1].lower()
                # this gets most right, but fix svg+html, plain
                attr = attr.replace('+xml', '').replace('plain', 'text')
                setattr(out, attr, data)
            if msg_type == 'pyout':
                out.prompt_number = content['execution_count']
        elif msg_type == 'pyerr':
            out.ename = content['ename']
            out.evalue = content['evalue']
            out.traceback = content['traceback']
        else:
            print("unhandled iopub msg:", msg_type)

        outs.append(out)
    return outs


def test_notebook(nb):
    km = KernelManager()
    km.start_kernel(extra_arguments=['--pylab=inline'],
                    stderr=open(os.devnull, 'w'))
    try:
        kc = km.client()
        kc.start_channels()
        iopub = kc.iopub_channel
    except AttributeError:
        # IPython 0.13
        kc = km
        kc.start_channels()
        iopub = kc.sub_channel
    shell = kc.shell_channel

    # run %pylab inline, because some notebooks assume this
    # even though they shouldn't
    shell.execute("pass")
    shell.get_msg()
    while True:
        try:
            iopub.get_msg(timeout=1)
        except Empty:
            break

    successes = 0
    failures = 0
    errors = 0
    for ws in nb.worksheets:
        for i, cell in enumerate(ws.cells):
            if cell.cell_type != 'code':
                continue
            try:
                outs = run_cell(shell, iopub, cell)
            except Exception as e:
                print("failed to run cell:", repr(e))
                print(cell.input)
                errors += 1
                continue

            failed = False
            if len(outs) != len(cell.outputs):
                print("output length mismatch (expected {}, got {})".format(
                      len(cell.outputs), len(outs)))
                failed = True
            for out, ref in zip(outs, cell.outputs):
                if not compare_outputs(out, ref):
                    failed = True
            print("cell %d: " % i, end="")
            if failed:
                print("FAIL")
                failures += 1
            else:
                print("OK")
                successes += 1

    print()
    print("tested notebook %s" % nb.metadata.name)
    print("    %3i cells successfully replicated" % successes)
    if failures:
        print("    %3i cells mismatched output" % failures)
    if errors:
        print("    %3i cells failed to complete" % errors)
    kc.stop_channels()
    km.shutdown_kernel()
    del km
    if failures | errors:
        sys.exit(1)

if __name__ == '__main__':
    for ipynb in sys.argv[1:]:
        print("testing %s" % ipynb)
        with open(ipynb) as f:
            nb = reads(f.read(), 'json')
        test_notebook(nb)