# debugcommands.py - debug logic for remotefilelog
#
# Copyright 2013 Facebook, Inc.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import

import hashlib
import os
import zlib

from mercurial.node import bin, hex, nullid, short
from mercurial.i18n import _
from mercurial import (
    error,
    filelog,
    revlog,
)
from . import (
    constants,
    datapack,
    extutil,
    fileserverclient,
    historypack,
    repack,
    shallowutil,
)

def debugremotefilelog(ui, path, **opts):
    decompress = opts.get('decompress')

    size, firstnode, mapping = parsefileblob(path, decompress)

    ui.status(_("size: %s bytes\n") % (size))
    ui.status(_("path: %s \n") % (path))
    ui.status(_("key: %s \n") % (short(firstnode)))
    ui.status(_("\n"))
    ui.status(_("%12s => %12s %13s %13s %12s\n") %
              ("node", "p1", "p2", "linknode", "copyfrom"))

    queue = [firstnode]
    while queue:
        node = queue.pop(0)
        p1, p2, linknode, copyfrom = mapping[node]
        ui.status(_("%s => %s  %s  %s  %s\n") %
            (short(node), short(p1), short(p2), short(linknode), copyfrom))
        if p1 != nullid:
            queue.append(p1)
        if p2 != nullid:
            queue.append(p2)

def buildtemprevlog(repo, file):
    # get filename key
    filekey = hashlib.sha1(file).hexdigest()
    filedir = os.path.join(repo.path, 'store/data', filekey)

    # sort all entries based on linkrev
    fctxs = []
    for filenode in os.listdir(filedir):
        if '_old' not in filenode:
            fctxs.append(repo.filectx(file, fileid=bin(filenode)))

    fctxs = sorted(fctxs, key=lambda x: x.linkrev())

    # add to revlog
    temppath = repo.sjoin('data/temprevlog.i')
    if os.path.exists(temppath):
        os.remove(temppath)
    r = filelog.filelog(repo.svfs, 'temprevlog')

    class faket(object):
        def add(self, a, b, c):
            pass
    t = faket()
    for fctx in fctxs:
        if fctx.node() not in repo:
            continue

        p = fctx.filelog().parents(fctx.filenode())
        meta = {}
        if fctx.renamed():
            meta['copy'] = fctx.renamed()[0]
            meta['copyrev'] = hex(fctx.renamed()[1])

        r.add(fctx.data(), meta, t, fctx.linkrev(), p[0], p[1])

    return r

def debugindex(orig, ui, repo, file_=None, **opts):
    """dump the contents of an index file"""
    if (opts.get('changelog') or
        opts.get('manifest') or
        opts.get('dir') or
        not shallowutil.isenabled(repo) or
        not repo.shallowmatch(file_)):
        return orig(ui, repo, file_, **opts)

    r = buildtemprevlog(repo, file_)

    # debugindex like normal
    format = opts.get('format', 0)
    if format not in (0, 1):
        raise error.Abort(_("unknown format %d") % format)

    generaldelta = r.version & revlog.FLAG_GENERALDELTA
    if generaldelta:
        basehdr = ' delta'
    else:
        basehdr = '  base'

    if format == 0:
        ui.write(("   rev    offset  length " + basehdr + " linkrev"
                  " nodeid       p1           p2\n"))
    elif format == 1:
        ui.write(("   rev flag   offset   length"
                  "     size " + basehdr + "   link     p1     p2"
                  "       nodeid\n"))

    for i in r:
        node = r.node(i)
        if generaldelta:
            base = r.deltaparent(i)
        else:
            base = r.chainbase(i)
        if format == 0:
            try:
                pp = r.parents(node)
            except Exception:
                pp = [nullid, nullid]
            ui.write("% 6d % 9d % 7d % 6d % 7d %s %s %s\n" % (
                    i, r.start(i), r.length(i), base, r.linkrev(i),
                    short(node), short(pp[0]), short(pp[1])))
        elif format == 1:
            pr = r.parentrevs(i)
            ui.write("% 6d %04x % 8d % 8d % 8d % 6d % 6d % 6d % 6d %s\n" % (
                    i, r.flags(i), r.start(i), r.length(i), r.rawsize(i),
                    base, r.linkrev(i), pr[0], pr[1], short(node)))

def debugindexdot(orig, ui, repo, file_):
    """dump an index DAG as a graphviz dot file"""
    if not shallowutil.isenabled(repo):
        return orig(ui, repo, file_)

    r = buildtemprevlog(repo, os.path.basename(file_)[:-2])

    ui.write(("digraph G {\n"))
    for i in r:
        node = r.node(i)
        pp = r.parents(node)
        ui.write("\t%d -> %d\n" % (r.rev(pp[0]), i))
        if pp[1] != nullid:
            ui.write("\t%d -> %d\n" % (r.rev(pp[1]), i))
    ui.write("}\n")

def verifyremotefilelog(ui, path, **opts):
    decompress = opts.get('decompress')

    for root, dirs, files in os.walk(path):
        for file in files:
            if file == "repos":
                continue
            filepath = os.path.join(root, file)
            size, firstnode, mapping = parsefileblob(filepath, decompress)
            for p1, p2, linknode, copyfrom in mapping.itervalues():
                if linknode == nullid:
                    actualpath = os.path.relpath(root, path)
                    key = fileserverclient.getcachekey("reponame", actualpath,
                                                       file)
                    ui.status("%s %s\n" % (key, os.path.relpath(filepath,
                                                                path)))

def _decompressblob(raw):
    return zlib.decompress(raw)

def parsefileblob(path, decompress):
    raw = None
    f = open(path, "r")
    try:
        raw = f.read()
    finally:
        f.close()

    if decompress:
        raw = _decompressblob(raw)

    offset, size, flags = shallowutil.parsesizeflags(raw)
    start = offset + size

    firstnode = None

    mapping = {}
    while start < len(raw):
        divider = raw.index('\0', start + 80)

        currentnode = raw[start:(start + 20)]
        if not firstnode:
            firstnode = currentnode

        p1 = raw[(start + 20):(start + 40)]
        p2 = raw[(start + 40):(start + 60)]
        linknode = raw[(start + 60):(start + 80)]
        copyfrom = raw[(start + 80):divider]

        mapping[currentnode] = (p1, p2, linknode, copyfrom)
        start = divider + 1

    return size, firstnode, mapping

def debugdatapack(ui, *paths, **opts):
    for path in paths:
        if '.data' in path:
            path = path[:path.index('.data')]
        ui.write("%s:\n" % path)
        dpack = datapack.datapack(path)
        node = opts.get('node')
        if node:
            deltachain = dpack.getdeltachain('', bin(node))
            dumpdeltachain(ui, deltachain, **opts)
            return

        if opts.get('long'):
            hashformatter = hex
            hashlen = 42
        else:
            hashformatter = short
            hashlen = 14

        lastfilename = None
        totaldeltasize = 0
        totalblobsize = 0
        def printtotals():
            if lastfilename is not None:
                ui.write("\n")
            if not totaldeltasize or not totalblobsize:
                return
            difference = totalblobsize - totaldeltasize
            deltastr = "%0.1f%% %s" % (
                (100.0 * abs(difference) / totalblobsize),
                ("smaller" if difference > 0 else "bigger"))

            ui.write(("Total:%s%s  %s (%s)\n") % (
                "".ljust(2 * hashlen - len("Total:")),
                str(totaldeltasize).ljust(12),
                str(totalblobsize).ljust(9),
                deltastr
            ))

        bases = {}
        nodes = set()
        failures = 0
        for filename, node, deltabase, deltalen in dpack.iterentries():
            bases[node] = deltabase
            if node in nodes:
                ui.write(("Bad entry: %s appears twice\n" % short(node)))
                failures += 1
            nodes.add(node)
            if filename != lastfilename:
                printtotals()
                name = '(empty name)' if filename == '' else filename
                ui.write("%s:\n" % name)
                ui.write("%s%s%s%s\n" % (
                    "Node".ljust(hashlen),
                    "Delta Base".ljust(hashlen),
                    "Delta Length".ljust(14),
                    "Blob Size".ljust(9)))
                lastfilename = filename
                totalblobsize = 0
                totaldeltasize = 0

            # Metadata could be missing, in which case it will be an empty dict.
            meta = dpack.getmeta(filename, node)
            if constants.METAKEYSIZE in meta:
                blobsize = meta[constants.METAKEYSIZE]
                totaldeltasize += deltalen
                totalblobsize += blobsize
            else:
                blobsize = "(missing)"
            ui.write("%s  %s  %s%s\n" % (
                hashformatter(node),
                hashformatter(deltabase),
                str(deltalen).ljust(14),
                blobsize))

        if filename is not None:
            printtotals()

        failures += _sanitycheck(ui, set(nodes), bases)
        if failures > 1:
            ui.warn(("%d failures\n" % failures))
            return 1

def _sanitycheck(ui, nodes, bases):
    """
    Does some basic sanity checking on a packfiles with ``nodes`` ``bases`` (a
    mapping of node->base):

    - Each deltabase must itself be a node elsewhere in the pack
    - There must be no cycles
    """
    failures = 0
    for node in nodes:
        seen = set()
        current = node
        deltabase = bases[current]

        while deltabase != nullid:
            if deltabase not in nodes:
                ui.warn(("Bad entry: %s has an unknown deltabase (%s)\n" %
                        (short(node), short(deltabase))))
                failures += 1
                break

            if deltabase in seen:
                ui.warn(("Bad entry: %s has a cycle (at %s)\n" %
                        (short(node), short(deltabase))))
                failures += 1
                break

            current = deltabase
            seen.add(current)
            deltabase = bases[current]
        # Since ``node`` begins a valid chain, reset/memoize its base to nullid
        # so we don't traverse it again.
        bases[node] = nullid
    return failures

def dumpdeltachain(ui, deltachain, **opts):
    hashformatter = hex
    hashlen = 40

    lastfilename = None
    for filename, node, filename, deltabasenode, delta in deltachain:
        if filename != lastfilename:
            ui.write("\n%s\n" % filename)
            lastfilename = filename
        ui.write("%s  %s  %s  %s\n" % (
            "Node".ljust(hashlen),
            "Delta Base".ljust(hashlen),
            "Delta SHA1".ljust(hashlen),
            "Delta Length".ljust(6),
        ))

        ui.write("%s  %s  %s  %s\n" % (
            hashformatter(node),
            hashformatter(deltabasenode),
            hashlib.sha1(delta).hexdigest(),
            len(delta)))

def debughistorypack(ui, path):
    if '.hist' in path:
        path = path[:path.index('.hist')]
    hpack = historypack.historypack(path)

    lastfilename = None
    for entry in hpack.iterentries():
        filename, node, p1node, p2node, linknode, copyfrom = entry
        if filename != lastfilename:
            ui.write("\n%s\n" % filename)
            ui.write("%s%s%s%s%s\n" % (
                "Node".ljust(14),
                "P1 Node".ljust(14),
                "P2 Node".ljust(14),
                "Link Node".ljust(14),
                "Copy From"))
            lastfilename = filename
        ui.write("%s  %s  %s  %s  %s\n" % (short(node), short(p1node),
            short(p2node), short(linknode), copyfrom))

def debugwaitonrepack(repo):
    with extutil.flock(repack.repacklockvfs(repo).join('repacklock'), ''):
        return

def debugwaitonprefetch(repo):
    with repo._lock(repo.svfs, "prefetchlock", True, None,
                         None, _('prefetching in %s') % repo.origroot):
        pass