#!/usr/bin/env python
# vim: ts=8 sts=4 sw=4 et ai si
# Author: Douglas Clowes 2013 (dcl@ansto.gov.au)

#
# Program to compare what *is* deployed with *was* deployed.
# It uses the file FILEMAP.TXT which can be created after the deployment.
# The location of FILEMAP.TXT may be different to the deployment path.
#
# For example, to compare what is on echidna (without a FILEMAP.TXT file) with
# what existed at the time it was deployed:
#
# sshfs -o ro -o follow_symlinks echidna@ics2-echidna.nbi.ansto.gov.au:/usr/local/sics mnt
# git checkout git checkout 5579f3e
# git checkout merge-replace -- deploySICS.sh
# ./deploySICS.sh -n echidna localhost
# python compare_deploy.py --manifest=FILEMAP.TXT mnt/newserver/
# ...
# fusermount -u mnt
#
#Notes:
# "sshfs -o ro" mount the echidna tree read only
# the 5579f3e is from the DEPLOYMENT.TXT file on echidna (mnt/server/DEPLOYMENT.TXT)
# The first checkout is to get what *was* deployed to echidna in the working directory
# The second checkout is just to get a deploySICS.sh that produces FILEMAP.TXT in staging
# The "./deploySICS.sh -n" does NOT deploy anywhere but creates FILEMAP.TXT in staging
# The compare_deploy.py uses FILEMAP.TXT from the staging tree produced by the "./deploySICS.sh -n"
# The compare_deploy.py path is to what *is* deployed on echidna
# The untracked files may be manually deployed and missing from MANIFEST.TXT
# The untracked files may be new, modified, test or junk 
# You can then "gvim -d " then cut/paste lines emitted under "Changed Files:" (or diff)
#
import os
import re
import sys
import argparse
import difflib
import shutil

def load_manifest(theManifest):
    '''
    This function loads the manifest file ("FILEMAP.TXT") which consists of a
    series of shell variables followed by the output of various 'cp -v'
    commands and produces two dictionaries, one for the assignments (shell variables)
    and one for the filemap (file associations). The shell variables give
    context to the file mapping.
    '''
    # get the lines from the manifest file with the newline removed
    contents = [j[:-1] for j in open(theManifest).readlines()]

    # divide the lines into assignments and filemaps
    assignments = []
    filemaps = []
    for line in contents:
        if "->" in line:
            filemaps.append(line)
        else:
            assignments.append(line)

    # parse the assignments and create the assignment map which maps shell variables (left)
    # from the deploy script to their value at the time of deployment
    assignment_map = {}
    for line in assignments:
        left, right = line.split("=")
        assignment_map[left] = right

    # parse the file associations and create the file map which maps the files in the
    # destination tree (right) to the file in the source tree from which they came (left)
    filemap_map = {}
    for line in filemaps:
        if line[0] in "`'":
            val = re.sub(r"^[`'](.*)[`'] -> [`'](.*)[`'].*", r"\1|\2", line)
        else:
            val = re.sub(r"^(.*) -> (.*)", r"\1|\2", line)
        if val == line:
            # unexpected, probably an error
            print "Val:", val
        else:
            left, right = val.split("|")
            if (left + "|" + right) != val:
                # unexpected, probably an error
                print "LR:", left, right
            else:
                # use the assignment map to remove the staging (temporary) directory
                # from the front of the filename and make it independent of that
                # and reduce leading slashes to one only
                if right.startswith(assignment_map["TEMPDIR"]):
                    right = right[len(assignment_map["TEMPDIR"]):]
                    while right.startswith("//"):
                        right = right[1:]
                # use the assignment map to remove the destination directory
                # from the front of the filename and make it independent of that
                # and remove leading slashes
                if right.startswith(assignment_map["DESTDIR"]):
                    right = right[len(assignment_map["DESTDIR"]):]
                    while right.startswith("/"):
                        right = right[1:]
                    prefix = "newserver/"
                    if right.startswith(prefix):
                        right = right[len(prefix):]
                else:
                    # unexpected, probably an error
                    print "LR+:", left, right
                # Note: map[destination] = source
                filemap_map[right] = left

    return (assignment_map, filemap_map)

def load_dir(theDir):
    '''
    Walk the directory tree and populate a double map with the filename and directory in which it was found
    '''
    myDirs = {}
    theLen = len(theDir) + 1
    for root, dirs, files in os.walk(theDir):
        for file in files:
            # Don't even put these files into the map
            if file.endswith((".swp", ".swo", ".hdf", "~", ".bck", ".pyc")):
                continue
            if file.startswith(("core.", "SICServer")):
                    continue
            if not file in myDirs:
                myDirs[file] = {}
            myDirs[file][root[theLen:]] = {}
    return myDirs

if __name__ == "__main__":
    default_dir = "/usr/local/TEST_SICS/taipan/nbi/sics/taipan"
    verbose = False
    parser = argparse.ArgumentParser(description = "Compare a deployed instrument tree with a repository")
    parser.add_argument("-v", "--verbose", dest="verbose", action="store_true", help="emit tables for debugging")
    parser.add_argument("--link", dest="link", action="store_true", help="link deployed files to /tmp tree")
    parser.add_argument("--copy", dest="copy", action="store_true", help="copy deployed files to /tmp tree")
    parser.add_argument("-m", "--manifest", dest="manifest", help="specify another manifest directory")
    parser.add_argument("path", nargs="?", default = default_dir, help="directory containing FILEMAP.TXT")
    args = parser.parse_args()
    if args.verbose:
        verbose = True
    default_dir = os.path.abspath(args.path)
    if default_dir.endswith("FILEMAP.TXT"):
        default_dir = os.path.dirname(default_dir)
    if args.manifest:
        temp_dir = args.manifest
        if temp_dir.endswith("FILEMAP.TXT"):
            temp_dir = os.path.dirname(temp_dir)
        default_manifest = os.path.join(temp_dir, "FILEMAP.TXT")
    else:
        default_manifest = os.path.join(default_dir, "FILEMAP.TXT")
    root_dir = os.path.dirname(default_dir)
    print "path:", args.path
    print "dest:", default_dir
    print "root:", root_dir
    print "--manifest:", args.manifest
    print "Manifest:", default_manifest

    amap, fmap = load_manifest(default_manifest)

    if verbose:
        print "Assignments:"
        for key in sorted(amap):
            print "  ", key, "=", amap[key]

        print "Contents:"
        for key in sorted(fmap):
            print "  ", key, "=", fmap[key]

    gmap = load_dir(default_dir)

    if verbose:
        print "Target:"
        for key in sorted(gmap):
            print "  ", key
            for entry in sorted(gmap[key]):
                print "    ", entry

    print "Untracked Files:"
    for key in sorted(gmap):
        if key.endswith((".swp", ".swo", ".hdf", "~", ".bck", ".pyc")):
            continue
        if key.startswith(("core.", "SICServer")):
                continue
        for entry in sorted(gmap[key]):
            if entry.endswith(("/data", "/log")):
                continue
            if "/data/" in entry:
                continue
            if os.path.join(entry, key) not in fmap:
                #print "Looking in fmap for", os.path.join(entry, key)
                print os.path.join(default_dir, os.path.join(entry, key))

    print "Changed Files:"
    for key in sorted(gmap):
        if key.endswith((".swp", ".swo", ".hdf", "~", ".bck", ".pyc")):
            continue
        if key.startswith(("core.", "SICServer")):
                continue
        for entry in sorted(gmap[key]):
            target = os.path.join(entry, key)
            #print "Looking in fmap for", os.path.join(entry, key)
            if target in fmap:
                source = os.path.join(amap["SRCDIR"], fmap[target])
                source = os.path.join(os.getenv("PWD"), fmap[target])
                destin = os.path.join(default_dir, target)
                if not (os.path.exists(source) and os.path.exists(destin)):
                    print "    Compare:", source, destin
                    if not os.path.exists(source):
                        print "        ", source, "does not exist"
                    if not os.path.exists(destin):
                        print "        ", destin, "does not exist"
                    continue
                delta = list(difflib.unified_diff(open(source).readlines(), open(destin).readlines()))
                delta_len = len(delta)
                if delta_len > 0:
                    if verbose:
                        print delta
                    print source, destin, "#%d" % delta_len

    if args.link:
        print "Linking Files:"
        count = 0
        lines = []
        for key in sorted(gmap):
            if key.endswith((".swp", ".swo", ".hdf", "~", ".bck", ".pyc")):
                continue
            if key.startswith(("core.", "SICServer")):
                    continue
            for entry in sorted(gmap[key]):
                target = os.path.join(entry, key)
                #print "Looking in fmap for", os.path.join(entry, key)
                if target in fmap:
                    source = os.path.join(amap["SRCDIR"], fmap[target])
                    source = os.path.join(os.getenv("PWD"), fmap[target])
                    destin = os.path.join(default_dir, target)
                    if not (os.path.exists(source) and os.path.exists(destin)):
                        print "    Linking:", source, destin
                        if not os.path.exists(source):
                            print "        ", source, "does not exist"
                        if not os.path.exists(destin):
                            print "        ", destin, "does not exist"
                        continue
                    lines.append((destin, fmap[target]))
        if len(lines) > 0:
            tgt = "/tmp/link_%s" % str(os.getpid())
            if (os.path.exists(tgt)):
                for root, disr, files in os.walk(tgt, topdown=False):
                    for name in files:
                        os.remove(os.path.join(root, name))
                    for name in dirs:
                        os.rmdir(os.path.join(root, name))
            os.mkdir(tgt)
            for line in lines:
                source = line[0]
                destin =  os.path.abspath(os.path.join(tgt, line[1]))
                if not destin.startswith(tgt):
                    print "Cannot link: %s to %s" % (source, destin)
                    continue
                try:
                    os.makedirs(os.path.dirname(destin))
                except:
                    pass
                if verbose:
                    cmd = "ln -s %s %s" % (source, destin)
                    print cmd
                if os.path.exists(destin):
                    delta = list(difflib.unified_diff(open(source).readlines(), open(destin).readlines()))
                    if len(delta) == 0:
                        continue
                    print "Duplicate Link:", destin
                    continue
                try:
                    os.symlink(source, destin)
                    count += 1
                except:
                    pass
            print "Links (%d) in: %s" % (count, tgt)


    if args.copy:
        print "Copying Files:"
        count = 0
        lines = []
        for key in sorted(gmap):
            if key.endswith((".swp", ".swo", ".hdf", "~", ".bck", ".pyc")):
                continue
            if key.startswith(("core.", "SICServer")):
                    continue
            for entry in sorted(gmap[key]):
                target = os.path.join(entry, key)
                #print "Looking in fmap for", os.path.join(entry, key)
                if target in fmap:
                    source = os.path.join(amap["SRCDIR"], fmap[target])
                    source = os.path.join(os.getenv("PWD"), fmap[target])
                    destin = os.path.join(default_dir, target)
                    if not (os.path.exists(source) and os.path.exists(destin)):
                        print "    Copying:", source, destin
                        if not os.path.exists(source):
                            print "        ", source, "does not exist"
                        if not os.path.exists(destin):
                            print "        ", destin, "does not exist"
                        continue
                    lines.append((destin, fmap[target]))
        if len(lines) > 0:
            tgt = "/tmp/copy_%s" % str(os.getpid())
            if (os.path.exists(tgt)):
                for root, disr, files in os.walk(tgt, topdown=False):
                    for name in files:
                        os.remove(os.path.join(root, name))
                    for name in dirs:
                        os.rmdir(os.path.join(root, name))
            os.mkdir(tgt)
            for line in lines:
                source = os.path.abspath(line[0])
                destin =  os.path.abspath(os.path.join(tgt, line[1]))
                if not destin.startswith(tgt):
                    print "Cannot copy: %s to %s" % (source, destin)
                    continue
                try:
                    os.makedirs(os.path.dirname(destin))
                except:
                    pass
                if verbose:
                    cmd = "cp -p %s %s" % (source, destin)
                    print cmd
                if os.path.exists(destin):
                    delta = list(difflib.unified_diff(open(source).readlines(), open(destin).readlines()))
                    if len(delta) == 0:
                        continue
                    print "Duplicate Copy:", destin
                    continue
                try:
                    shutil.copyfile(source, destin)
                    shutil.copystat(source, destin)
                    count += 1
                except:
                    pass
            print "Copies (%d) in: %s" % (count, tgt)