"""Check for pads that have changed since last sync (according to .meta.json)"""
import json
import os
import re
import sys
import time
from argparse import ArgumentParser
from datetime import datetime
from fnmatch import fnmatch
from urllib.parse import quote, urlencode
from urllib.request import HTTPError
from xml.etree import ElementTree as ET

import asks
import html5lib
import trio

from etherpump.commands.common import *  # noqa
from etherpump.commands.html5tidy import html5tidy

"""
pull(meta):
    Update meta data files for those that have changed.
    Check for changed pads by looking at revisions & comparing to existing
todo...
use/prefer public interfaces ? (export functions)
"""


def try_deleting(files):
    for f in files:
        try:
            os.remove(f)
        except OSError:
            pass


def build_argument_parser(args):
    parser = ArgumentParser(
        "Check for pads that have changed since last sync (according to .meta.json)"
    )
    parser.add_argument("padid", nargs="*", default=[])
    parser.add_argument(
        "--glob", default=False, help="download pads matching a glob pattern"
    )
    parser.add_argument(
        "--padinfo",
        default=".etherpump/settings.json",
        help="settings, default: .etherpump/settings.json",
    )
    parser.add_argument(
        "--zerorevs",
        default=False,
        action="store_true",
        help="include pads with zero revisions, default: False (i.e. pads with no revisions are skipped)",
    )
    parser.add_argument(
        "--pub",
        default="p",
        help="folder to store files for public pads, default: p",
    )
    parser.add_argument(
        "--group",
        default="g",
        help="folder to store files for group pads, default: g",
    )
    parser.add_argument(
        "--skip",
        default=None,
        type=int,
        help="skip this many items, default: None",
    )
    parser.add_argument(
        "--connection",
        default=200,
        type=int,
        help="number of connections to run concurrently",
    )
    parser.add_argument(
        "--meta",
        default=False,
        action="store_true",
        help="download meta to PADID.meta.json, default: False",
    )
    parser.add_argument(
        "--text",
        default=False,
        action="store_true",
        help="download text to PADID.txt, default: False",
    )
    parser.add_argument(
        "--html",
        default=False,
        action="store_true",
        help="download html to PADID.html, default: False",
    )
    parser.add_argument(
        "--dhtml",
        default=False,
        action="store_true",
        help="download dhtml to PADID.diff.html, default: False",
    )
    parser.add_argument(
        "--all",
        default=False,
        action="store_true",
        help="download all files (meta, text, html, dhtml), default: False",
    )
    parser.add_argument(
        "--folder",
        default=False,
        action="store_true",
        help="dump files in a folder named PADID (meta, text, html, dhtml), default: False",
    )
    parser.add_argument(
        "--output",
        default=False,
        action="store_true",
        help="output changed padids on stdout",
    )
    parser.add_argument(
        "--force",
        default=False,
        action="store_true",
        help="reload, even if revisions count matches previous",
    )
    parser.add_argument(
        "--no-raw-ext",
        default=False,
        action="store_true",
        help="save plain text as padname with no (additional) extension",
    )
    parser.add_argument(
        "--fix-names",
        default=False,
        action="store_true",
        help="normalize padid's (no spaces, special control chars) for use in file names",
    )
    parser.add_argument(
        "--filter-ext", default=None, help="filter pads by extension"
    )
    parser.add_argument(
        "--css",
        default="/styles.css",
        help="add css url to output pages, default: /styles.css",
    )
    parser.add_argument(
        "--script",
        default="/versions.js",
        help="add script url to output pages, default: /versions.js",
    )
    parser.add_argument(
        "--nopublish",
        default="__NOPUBLISH__",
        help="no publish magic word, default: __NOPUBLISH__",
    )
    parser.add_argument(
        "--publish",
        default="__PUBLISH__",
        help="the publish magic word, default: __PUBLISH__",
    )
    parser.add_argument(
        "--publish-opt-in",
        default=False,
        action="store_true",
        help="ensure `--publish` is honoured instead of `--nopublish`",
    )
    return parser


async def get_padids(args, info, data, session):
    if args.padid:
        padids = args.padid
    elif args.glob:
        url = info["localapiurl"] + "listAllPads?" + urlencode(data)
        padids = await agetjson(session, url)
        padids = padids["data"]["padIDs"]
        padids = [x for x in padids if fnmatch(x, args.glob)]
    else:
        url = info["localapiurl"] + "listAllPads?" + urlencode(data)
        padids = await agetjson(session, url)
        padids = padids["data"]["padIDs"]

    padids.sort()
    return padids


async def handle_pad(args, padid, data, info, session):
    raw_ext = ".raw.txt"
    if args.no_raw_ext:
        raw_ext = ""

    data["padID"] = padid
    p = padpath(padid, args.pub, args.group, args.fix_names)
    if args.folder:
        p = os.path.join(p, padid)

    metapath = p + ".meta.json"
    revisions = None
    tries = 1
    skip = False
    padurlbase = re.sub(r"api/1.2.9/$", "p/", info["apiurl"])
    meta = {}

    while True:
        try:
            if os.path.exists(metapath):
                async with await trio.open_file(metapath) as f:
                    contents = await f.read()
                    meta.update(json.loads(contents))
                url = (
                    info["localapiurl"] + "getRevisionsCount?" + urlencode(data)
                )
                response = await agetjson(session, url)
                revisions = response["data"]["revisions"]
                if meta["revisions"] == revisions and not args.force:
                    skip = True
                    reason = "No new revisions, we already have the latest local copy"
                    break

            meta["padid"] = padid
            versions = meta["versions"] = []
            versions.append(
                {"url": padurlbase + quote(padid), "type": "pad", "code": 200,}
            )

            if revisions is None:
                url = (
                    info["localapiurl"] + "getRevisionsCount?" + urlencode(data)
                )
                response = await agetjson(session, url)
                meta["revisions"] = response["data"]["revisions"]
            else:
                meta["revisions"] = revisions

            if (meta["revisions"] == 0) and (not args.zerorevs):
                skip = True
                reason = "0 revisions, this pad was never edited"
                break

            # todo: load more metadata!
            meta["group"], meta["pad"] = splitpadname(padid)
            meta["pathbase"] = p

            url = info["localapiurl"] + "getLastEdited?" + urlencode(data)
            response = await agetjson(session, url)
            meta["lastedited_raw"] = int(response["data"]["lastEdited"])

            meta["lastedited_iso"] = datetime.fromtimestamp(
                int(meta["lastedited_raw"]) / 1000
            ).isoformat()

            url = info["localapiurl"] + "listAuthorsOfPad?" + urlencode(data)
            response = await agetjson(session, url)
            meta["author_ids"] = response["data"]["authorIDs"]

            break
        except HTTPError as e:
            tries += 1
            if tries > 3:
                print(
                    "Too many failures ({0}), skipping".format(padid),
                    file=sys.stderr,
                )
                skip = True
                reason = "PANIC, couldn't download the pad contents"
                break
            else:
                await trio.sleep(1)
        except TypeError as e:
            print(
                "Type Error loading pad {0} (phantom pad?), skipping".format(
                    padid
                ),
                file=sys.stderr,
            )
            skip = True
            reason = "PANIC, couldn't download the pad contents"
            break

    if skip:
        print("[ ] {} (skipped, reason: {})".format(padid, reason))
        return

    if args.output:
        print(padid)

    if args.all or (args.meta or args.text or args.html or args.dhtml):
        try:
            path = trio.Path(os.path.split(metapath)[0])
            await path.mkdir()
        except OSError:
            print("PANIC: unable to create {}".format(str(path)))

    if args.all or args.text:
        url = info["localapiurl"] + "getText?" + urlencode(data)
        text = await agetjson(session, url)
        ver = {"type": "text"}
        versions.append(ver)
        ver["code"] = text["_code"]
        if text["_code"] == 200:
            text = text["data"]["text"]

            ##########################################
            ## ENFORCE __NOPUBLISH__ MAGIC WORD
            ##########################################
            if args.nopublish and args.nopublish in text:
                # NEED TO PURGE ANY EXISTING DOCS
                try_deleting(
                    (
                        p + raw_ext,
                        p + ".raw.html",
                        p + ".diff.html",
                        p + ".meta.json",
                    )
                )
                print(
                    "[ ] {} (deleted, reason: explicit __NOPUBLISH__)".format(
                        padid
                    )
                )
                return

            ##########################################
            ## ENFORCE __PUBLISH__ MAGIC WORD
            ##########################################
            if args.publish_opt_in and args.publish not in text:
                try_deleting(
                    (
                        p + raw_ext,
                        p + ".raw.html",
                        p + ".diff.html",
                        p + ".meta.json",
                    )
                )
                print("[ ] {} (deleted, reason: publish opt-out)".format(padid))
                return

            ver["path"] = p + raw_ext
            ver["url"] = quote(ver["path"])
            async with await trio.open_file(ver["path"], "w") as f:
                await f.write(text)
            # once the content is settled, compute a hash
            # and link it in the metadata!

    links = []
    if args.css:
        links.append({"href": args.css, "rel": "stylesheet"})
    # todo, make this process reflect which files actually were made
    versionbaseurl = quote(padid)
    links.append(
        {
            "href": versions[0]["url"],
            "rel": "alternate",
            "type": "text/html",
            "title": "Etherpad",
        }
    )
    if args.all or args.text:
        links.append(
            {
                "href": versionbaseurl + raw_ext,
                "rel": "alternate",
                "type": "text/plain",
                "title": "Plain text",
            }
        )
    if args.all or args.html:
        links.append(
            {
                "href": versionbaseurl + ".raw.html",
                "rel": "alternate",
                "type": "text/html",
                "title": "HTML",
            }
        )
    if args.all or args.dhtml:
        links.append(
            {
                "href": versionbaseurl + ".diff.html",
                "rel": "alternate",
                "type": "text/html",
                "title": "HTML with author colors",
            }
        )
    if args.all or args.meta:
        links.append(
            {
                "href": versionbaseurl + ".meta.json",
                "rel": "alternate",
                "type": "application/json",
                "title": "Meta data",
            }
        )

    if args.all or args.dhtml:
        data["startRev"] = "0"
        url = info["localapiurl"] + "createDiffHTML?" + urlencode(data)
        html = await agetjson(session, url)
        ver = {"type": "diffhtml"}
        versions.append(ver)
        ver["code"] = html["_code"]
        if html["_code"] == 200:
            try:
                html = html["data"]["html"]
                ver["path"] = p + ".diff.html"
                ver["url"] = quote(ver["path"])
                doc = html5lib.parse(
                    html, treebuilder="etree", namespaceHTMLElements=False
                )
                html5tidy(
                    doc,
                    indent=True,
                    title=padid,
                    scripts=args.script,
                    links=links,
                )
                async with await trio.open_file(ver["path"], "w") as f:
                    output = ET.tostring(doc, method="html", encoding="unicode")
                    await f.write(output)
            except TypeError:
                ver["message"] = html["message"]

    # Process text, html, dhtml, all options
    if args.all or args.html:
        url = info["localapiurl"] + "getHTML?" + urlencode(data)
        html = await agetjson(session, url)
        ver = {"type": "html"}
        versions.append(ver)
        ver["code"] = html["_code"]
        if html["_code"] == 200:
            html = html["data"]["html"]
            ver["path"] = p + ".raw.html"
            ver["url"] = quote(ver["path"])
            doc = html5lib.parse(
                html, treebuilder="etree", namespaceHTMLElements=False
            )
            html5tidy(
                doc, indent=True, title=padid, scripts=args.script, links=links,
            )
            async with await trio.open_file(ver["path"], "w") as f:
                output = ET.tostring(doc, method="html", encoding="unicode")
                await f.write(output)

    # output meta
    if args.all or args.meta:
        ver = {"type": "meta"}
        versions.append(ver)
        ver["path"] = metapath
        ver["url"] = quote(metapath)
        async with await trio.open_file(metapath, "w") as f:
            await f.write(json.dumps(meta))

    print("[x] {} (saved)".format(padid))


async def handle_pads(args):
    session = asks.Session(connections=args.connection)
    info = loadpadinfo(args.padinfo)
    data = {"apikey": info["apikey"]}

    padids = await get_padids(args, info, data, session)
    if args.skip:
        padids = padids[args.skip : len(padids)]

    print("=" * 79)
    print("Etherpump is warming up the engines ...")
    print("=" * 79)

    start = time.time()
    async with trio.open_nursery() as nursery:
        for padid in padids:
            nursery.start_soon(handle_pad, args, padid, data, info, session)
    end = time.time()

    print("=" * 79)
    print(
        "Processed {} pads in {} seconds".format(
            len(padids), round(end - start, 2)
        )
    )
    print("=" * 79)


def main(args):
    p = build_argument_parser(args)
    args = p.parse_args(args)
    trio.run(handle_pads, args)