# ex:ts=4:sw=4:sts=4:et
# -*- tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*-
"""
BitBake Utility Functions
"""

# Copyright (C) 2004 Michael Lauer
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

import re, fcntl, os, string, stat, shutil, time
import sys
import errno
import logging
import bb
import bb.msg
from commands import getstatusoutput
from contextlib import contextmanager

logger = logging.getLogger("BitBake.Util")

# Version comparison
separators = ".-"

# Context used in better_exec, eval
_context = {
    "os": os,
    "bb": bb,
    "time": time,
}

def explode_version(s):
    r = []
    alpha_regexp = re.compile('^([a-zA-Z]+)(.*)$')
    numeric_regexp = re.compile('^(\d+)(.*)$')
    while (s != ''):
        if s[0] in string.digits:
            m = numeric_regexp.match(s)
            r.append(int(m.group(1)))
            s = m.group(2)
            continue
        if s[0] in string.letters:
            m = alpha_regexp.match(s)
            r.append(m.group(1))
            s = m.group(2)
            continue
        r.append(s[0])
        s = s[1:]
    return r

def vercmp_part(a, b):
    va = explode_version(a)
    vb = explode_version(b)
    sa = False
    sb = False
    while True:
        if va == []:
            ca = None
        else:
            ca = va.pop(0)
        if vb == []:
            cb = None
        else:
            cb = vb.pop(0)
        if ca == None and cb == None:
            return 0

        if isinstance(ca, basestring):
            sa = ca in separators
        if isinstance(cb, basestring):
            sb = cb in separators
        if sa and not sb:
            return -1
        if not sa and sb:
            return 1

        if ca > cb:
            return 1
        if ca < cb:
            return -1

def vercmp(ta, tb):
    (ea, va, ra) = ta
    (eb, vb, rb) = tb

    r = int(ea or 0) - int(eb or 0)
    if (r == 0):
        r = vercmp_part(va, vb)
    if (r == 0):
        r = vercmp_part(ra, rb)
    return r

_package_weights_ = {"pre":-2, "p":0, "alpha":-4, "beta":-3, "rc":-1}    # dicts are unordered
_package_ends_ = ["pre", "p", "alpha", "beta", "rc", "cvs", "bk", "HEAD" ]            # so we need ordered list

def relparse(myver):
    """Parses the last elements of a version number into a triplet, that can
    later be compared.
    """

    number = 0
    p1 = 0
    p2 = 0
    mynewver = myver.split('_')
    if len(mynewver) == 2:
        # an _package_weights_
        number = float(mynewver[0])
        match = 0
        for x in _package_ends_:
            elen = len(x)
            if mynewver[1][:elen] == x:
                match = 1
                p1 = _package_weights_[x]
                try:
                    p2 = float(mynewver[1][elen:])
                except:
                    p2 = 0
                break
        if not match:
            # normal number or number with letter at end
            divider = len(myver)-1
            if myver[divider:] not in "1234567890":
                # letter at end
                p1 = ord(myver[divider:])
                number = float(myver[0:divider])
            else:
                number = float(myver)
    else:
        # normal number or number with letter at end
        divider = len(myver)-1
        if myver[divider:] not in "1234567890":
            #letter at end
            p1 = ord(myver[divider:])
            number = float(myver[0:divider])
        else:
            number = float(myver)
    return [number, p1, p2]

__vercmp_cache__ = {}

def vercmp_string(val1, val2):
    """This takes two version strings and returns an integer to tell you whether
    the versions are the same, val1>val2 or val2>val1.
    """

    # quick short-circuit
    if val1 == val2:
        return 0
    valkey = val1 + " " + val2

    # cache lookup
    try:
        return __vercmp_cache__[valkey]
        try:
            return - __vercmp_cache__[val2 + " " + val1]
        except KeyError:
            pass
    except KeyError:
        pass

    # consider 1_p2 vc 1.1
    # after expansion will become (1_p2,0) vc (1,1)
    # then 1_p2 is compared with 1 before 0 is compared with 1
    # to solve the bug we need to convert it to (1,0_p2)
    # by splitting _prepart part and adding it back _after_expansion

    val1_prepart = val2_prepart = ''
    if val1.count('_'):
        val1, val1_prepart = val1.split('_', 1)
    if val2.count('_'):
        val2, val2_prepart = val2.split('_', 1)

    # replace '-' by '.'
    # FIXME: Is it needed? can val1/2 contain '-'?

    val1 = val1.split("-")
    if len(val1) == 2:
        val1[0] = val1[0] + "." + val1[1]
    val2 = val2.split("-")
    if len(val2) == 2:
        val2[0] = val2[0] + "." + val2[1]

    val1 = val1[0].split('.')
    val2 = val2[0].split('.')

    # add back decimal point so that .03 does not become "3" !
    for x in xrange(1, len(val1)):
        if val1[x][0] == '0' :
            val1[x] = '.' + val1[x]
    for x in xrange(1, len(val2)):
        if val2[x][0] == '0' :
            val2[x] = '.' + val2[x]

    # extend varion numbers
    if len(val2) < len(val1):
        val2.extend(["0"]*(len(val1)-len(val2)))
    elif len(val1) < len(val2):
        val1.extend(["0"]*(len(val2)-len(val1)))

    # add back _prepart tails
    if val1_prepart:
        val1[-1] += '_' + val1_prepart
    if val2_prepart:
        val2[-1] += '_' + val2_prepart
    # The above code will extend version numbers out so they
    # have the same number of digits.
    for x in xrange(0, len(val1)):
        cmp1 = relparse(val1[x])
        cmp2 = relparse(val2[x])
        for y in xrange(0, 3):
            myret = cmp1[y] - cmp2[y]
            if myret != 0:
                __vercmp_cache__[valkey] = myret
                return myret
    __vercmp_cache__[valkey] = 0
    return 0

def explode_deps(s):
    """
    Take an RDEPENDS style string of format:
    "DEPEND1 (optional version) DEPEND2 (optional version) ..."
    and return a list of dependencies.
    Version information is ignored.
    """
    r = []
    l = s.split()
    flag = False
    for i in l:
        if i[0] == '(':
            flag = True
            #j = []
        if not flag:
            r.append(i)
        #else:
        #    j.append(i)
        if flag and i.endswith(')'):
            flag = False
            # Ignore version
            #r[-1] += ' ' + ' '.join(j)
    return r

def explode_dep_versions(s):
    """
    Take an RDEPENDS style string of format:
    "DEPEND1 (optional version) DEPEND2 (optional version) ..."
    and return a dictionary of dependencies and versions.
    """
    r = {}
    l = s.replace(",", "").split()
    lastdep = None
    lastver = ""
    inversion = False
    for i in l:
        if i[0] == '(':
            inversion = True
            lastver = i[1:] or ""
            #j = []
        elif inversion and i.endswith(')'):
            inversion = False
            lastver = lastver + " " + (i[:-1] or "")
            r[lastdep] = lastver
        elif not inversion:
            r[i] = None
            lastdep = i
            lastver = ""
        elif inversion:
            lastver = lastver + " " + i

    return r

def join_deps(deps, commasep=True):
    """
    Take the result from explode_dep_versions and generate a dependency string
    """
    result = []
    for dep in deps:
        if deps[dep]:
            result.append(dep + " (" + deps[dep] + ")")
        else:
            result.append(dep)
    if commasep:
        return ", ".join(result)
    else:
        return " ".join(result)

def _print_trace(body, line):
    """
    Print the Environment of a Text Body
    """
    # print the environment of the method
    min_line = max(1, line-4)
    max_line = min(line + 4, len(body))
    for i in xrange(min_line, max_line + 1):
        if line == i:
            logger.error(' *** %.4d:%s', i, body[i-1])
        else:
            logger.error('     %.4d:%s', i, body[i-1])

def better_compile(text, file, realfile, mode = "exec"):
    """
    A better compile method. This method
    will print  the offending lines.
    """
    try:
        return compile(text, file, mode)
    except Exception as e:
        # split the text into lines again
        body = text.split('\n')
        logger.error("Error in compiling python function in %s", realfile)
        logger.error(str(e))
        if e.lineno:
            logger.error("The lines leading to this error were:")
            logger.error("\t%d:%s:'%s'", e.lineno, e.__class__.__name__, body[e.lineno-1])
            _print_trace(body, e.lineno)
        else:
            logger.error("The function causing this error was:")
            for line in body:
                logger.error(line)

        raise

def better_exec(code, context, text, realfile = "<code>"):
    """
    Similiar to better_compile, better_exec will
    print the lines that are responsible for the
    error.
    """
    import bb.parse
    if not hasattr(code, "co_filename"):
        code = better_compile(code, realfile, realfile)
    try:
        exec(code, _context, context)
    except Exception:
        (t, value, tb) = sys.exc_info()

        if t in [bb.parse.SkipPackage, bb.build.FuncFailed]:
            raise

        import traceback
        exception = traceback.format_exception_only(t, value)
        logger.error('Error executing a python function in %s:\n%s',
                     realfile, ''.join(exception))

        # Strip 'us' from the stack (better_exec call)
        tb = tb.tb_next

        textarray = text.split('\n')
        linefailed = traceback.tb_lineno(tb)

        tbextract = traceback.extract_tb(tb)
        tbformat = "\n".join(traceback.format_list(tbextract))
        logger.error("The stack trace of python calls that resulted in this exception/failure was:")
        for line in tbformat.split('\n'):
            logger.error(line)

        logger.error("The code that was being executed was:")
        _print_trace(textarray, linefailed)
        logger.error("(file: '%s', lineno: %s, function: %s)", tbextract[0][0], tbextract[0][1], tbextract[0][2])

        # See if this is a function we constructed and has calls back into other functions in
        # "text". If so, try and improve the context of the error by diving down the trace
        level = 0
        nexttb = tb.tb_next
        while nexttb is not None:
            if tbextract[level][0] == tbextract[level+1][0] and tbextract[level+1][2] == tbextract[level][0]:
                _print_trace(textarray, tbextract[level+1][1])
                logger.error("(file: '%s', lineno: %s, function: %s)", tbextract[level+1][0], tbextract[level+1][1], tbextract[level+1][2])
            else:
                 break
            nexttb = tb.tb_next
            level = level + 1

        raise

def simple_exec(code, context):
    exec(code, _context, context)

def better_eval(source, locals):
    return eval(source, _context, locals)

@contextmanager
def fileslocked(files):
    """Context manager for locking and unlocking file locks."""
    locks = []
    if files:
        for lockfile in files:
            locks.append(bb.utils.lockfile(lockfile))

    yield

    for lock in locks:
        bb.utils.unlockfile(lock)

def lockfile(name, shared=False, retry=True):
    """
    Use the file fn as a lock file, return when the lock has been acquired.
    Returns a variable to pass to unlockfile().
    """
    dirname = os.path.dirname(name)
    mkdirhier(dirname)

    if not os.access(dirname, os.W_OK):
        logger.error("Unable to acquire lock '%s', directory is not writable",
                     name)
        sys.exit(1)

    op = fcntl.LOCK_EX
    if shared:
        op = fcntl.LOCK_SH
    if not retry:
        op = op | fcntl.LOCK_NB

    while True:
        # If we leave the lockfiles lying around there is no problem
        # but we should clean up after ourselves. This gives potential
        # for races though. To work around this, when we acquire the lock
        # we check the file we locked was still the lock file on disk.
        # by comparing inode numbers. If they don't match or the lockfile
        # no longer exists, we start again.

        # This implementation is unfair since the last person to request the
        # lock is the most likely to win it.

        try:
            lf = open(name, 'a+')
            fileno = lf.fileno()
            fcntl.flock(fileno, op)
            statinfo = os.fstat(fileno)
            if os.path.exists(lf.name):
                statinfo2 = os.stat(lf.name)
                if statinfo.st_ino == statinfo2.st_ino:
                    return lf
            lf.close()
        except Exception:
            pass
        if not retry:
            return None

def unlockfile(lf):
    """
    Unlock a file locked using lockfile()
    """
    try:
        # If we had a shared lock, we need to promote to exclusive before
        # removing the lockfile. Attempt this, ignore failures.
        fcntl.flock(lf.fileno(), fcntl.LOCK_EX|fcntl.LOCK_NB)
        os.unlink(lf.name)
    except (IOError, OSError):
        pass
    fcntl.flock(lf.fileno(), fcntl.LOCK_UN)
    lf.close()

def md5_file(filename):
    """
    Return the hex string representation of the MD5 checksum of filename.
    """
    try:
        import hashlib
        m = hashlib.md5()
    except ImportError:
        import md5
        m = md5.new()

    for line in open(filename):
        m.update(line)
    return m.hexdigest()

def sha256_file(filename):
    """
    Return the hex string representation of the 256-bit SHA checksum of
    filename.  On Python 2.4 this will return None, so callers will need to
    handle that by either skipping SHA checks, or running a standalone sha256sum
    binary.
    """
    try:
        import hashlib
    except ImportError:
        return None

    s = hashlib.sha256()
    for line in open(filename):
        s.update(line)
    return s.hexdigest()

def preserved_envvars_exported():
    """Variables which are taken from the environment and placed in and exported
    from the metadata"""
    return [
        'BB_TASKHASH',
        'HOME',
        'LOGNAME',
        'PATH',
        'PWD',
        'SHELL',
        'TERM',
        'USER',
    ]

def preserved_envvars_exported_interactive():
    """Variables which are taken from the environment and placed in and exported
    from the metadata, for interactive tasks"""
    return [
        'COLORTERM',
        'DBUS_SESSION_BUS_ADDRESS',
        'DESKTOP_SESSION',
        'DESKTOP_STARTUP_ID',
        'DISPLAY',
        'GNOME_KEYRING_PID',
        'GNOME_KEYRING_SOCKET',
        'GPG_AGENT_INFO',
        'GTK_RC_FILES',
        'SESSION_MANAGER',
        'KRB5CCNAME',
        'SSH_AUTH_SOCK',
        'XAUTHORITY',
        'XDG_DATA_DIRS',
        'XDG_SESSION_COOKIE',
    ]

def preserved_envvars():
    """Variables which are taken from the environment and placed in the metadata"""
    v = [
        'BBPATH',
        'BB_PRESERVE_ENV',
        'BB_ENV_WHITELIST',
        'BB_ENV_EXTRAWHITE',
        'LANG',
        '_',
    ]
    return v + preserved_envvars_exported() + preserved_envvars_exported_interactive()

def filter_environment(good_vars):
    """
    Create a pristine environment for bitbake. This will remove variables that
    are not known and may influence the build in a negative way.
    """

    removed_vars = []
    for key in os.environ.keys():
        if key in good_vars:
            continue

        removed_vars.append(key)
        os.unsetenv(key)
        del os.environ[key]

    if len(removed_vars):
        logger.debug(1, "Removed the following variables from the environment: %s", ", ".join(removed_vars))

    return removed_vars

def create_interactive_env(d):
    for k in preserved_envvars_exported_interactive():
        os.setenv(k, bb.data.getVar(k, d, True))

def approved_variables():
    """
    Determine and return the list of whitelisted variables which are approved
    to remain in the envrionment.
    """
    approved = []
    if 'BB_ENV_WHITELIST' in os.environ:
        approved = os.environ['BB_ENV_WHITELIST'].split()
    else:
        approved = preserved_envvars()
    if 'BB_ENV_EXTRAWHITE' in os.environ:
        approved.extend(os.environ['BB_ENV_EXTRAWHITE'].split())
    return approved

def clean_environment():
    """
    Clean up any spurious environment variables. This will remove any
    variables the user hasn't chosen to preserve.
    """
    if 'BB_PRESERVE_ENV' not in os.environ:
        good_vars = approved_variables()
        filter_environment(good_vars)

def empty_environment():
    """
    Remove all variables from the environment.
    """
    for s in os.environ.keys():
        os.unsetenv(s)
        del os.environ[s]

def build_environment(d):
    """
    Build an environment from all exported variables.
    """
    import bb.data
    for var in bb.data.keys(d):
        export = bb.data.getVarFlag(var, "export", d)
        if export:
            os.environ[var] = bb.data.getVar(var, d, True) or ""

def remove(path, recurse=False):
    """Equivalent to rm -f or rm -rf"""
    if not path:
        return
    import os, errno, shutil, glob
    for name in glob.glob(path):
        try:
            os.unlink(name)
        except OSError as exc:
            if recurse and exc.errno == errno.EISDIR:
                shutil.rmtree(name)
            elif exc.errno != errno.ENOENT:
                raise

def prunedir(topdir):
    # Delete everything reachable from the directory named in 'topdir'.
    # CAUTION:  This is dangerous!
    for root, dirs, files in os.walk(topdir, topdown = False):
        for name in files:
            os.remove(os.path.join(root, name))
        for name in dirs:
            if os.path.islink(os.path.join(root, name)):
                os.remove(os.path.join(root, name))
            else:
                os.rmdir(os.path.join(root, name))
    os.rmdir(topdir)

#
# Could also use return re.compile("(%s)" % "|".join(map(re.escape, suffixes))).sub(lambda mo: "", var)
# but thats possibly insane and suffixes is probably going to be small
#
def prune_suffix(var, suffixes, d):
    # See if var ends with any of the suffixes listed and
    # remove it if found
    for suffix in suffixes:
        if var.endswith(suffix):
            return var.replace(suffix, "")
    return var

def mkdirhier(directory):
    """Create a directory like 'mkdir -p', but does not complain if
    directory already exists like os.makedirs
    """

    try:
        os.makedirs(directory)
    except OSError as e:
        if e.errno != errno.EEXIST:
            raise e

def movefile(src, dest, newmtime = None, sstat = None):
    """Moves a file from src to dest, preserving all permissions and
    attributes; mtime will be preserved even when moving across
    filesystems.  Returns true on success and false on failure. Move is
    atomic.
    """

    #print "movefile(" + src + "," + dest + "," + str(newmtime) + "," + str(sstat) + ")"
    try:
        if not sstat:
            sstat = os.lstat(src)
    except Exception as e:
        print("movefile: Stating source file failed...", e)
        return None

    destexists = 1
    try:
        dstat = os.lstat(dest)
    except:
        dstat = os.lstat(os.path.dirname(dest))
        destexists = 0

    if destexists:
        if stat.S_ISLNK(dstat[stat.ST_MODE]):
            try:
                os.unlink(dest)
                destexists = 0
            except Exception as e:
                pass

    if stat.S_ISLNK(sstat[stat.ST_MODE]):
        try:
            target = os.readlink(src)
            if destexists and not stat.S_ISDIR(dstat[stat.ST_MODE]):
                os.unlink(dest)
            os.symlink(target, dest)
            #os.lchown(dest,sstat[stat.ST_UID],sstat[stat.ST_GID])
            os.unlink(src)
            return os.lstat(dest)
        except Exception as e:
            print("movefile: failed to properly create symlink:", dest, "->", target, e)
            return None

    renamefailed = 1
    if sstat[stat.ST_DEV] == dstat[stat.ST_DEV]:
        try:
            os.rename(src, dest)
            renamefailed = 0
        except Exception as e:
            if e[0] != errno.EXDEV:
                # Some random error.
                print("movefile: Failed to move", src, "to", dest, e)
                return None
            # Invalid cross-device-link 'bind' mounted or actually Cross-Device

    if renamefailed:
        didcopy = 0
        if stat.S_ISREG(sstat[stat.ST_MODE]):
            try: # For safety copy then move it over.
                shutil.copyfile(src, dest + "#new")
                os.rename(dest + "#new", dest)
                didcopy = 1
            except Exception as e:
                print('movefile: copy', src, '->', dest, 'failed.', e)
                return None
        else:
            #we don't yet handle special, so we need to fall back to /bin/mv
            a = getstatusoutput("/bin/mv -f " + "'" + src + "' '" + dest + "'")
            if a[0] != 0:
                print("movefile: Failed to move special file:" + src + "' to '" + dest + "'", a)
                return None # failure
        try:
            if didcopy:
                os.lchown(dest, sstat[stat.ST_UID], sstat[stat.ST_GID])
                os.chmod(dest, stat.S_IMODE(sstat[stat.ST_MODE])) # Sticky is reset on chown
                os.unlink(src)
        except Exception as e:
            print("movefile: Failed to chown/chmod/unlink", dest, e)
            return None

    if newmtime:
        os.utime(dest, (newmtime, newmtime))
    else:
        os.utime(dest, (sstat[stat.ST_ATIME], sstat[stat.ST_MTIME]))
        newmtime = sstat[stat.ST_MTIME]
    return newmtime

def copyfile(src, dest, newmtime = None, sstat = None):
    """
    Copies a file from src to dest, preserving all permissions and
    attributes; mtime will be preserved even when moving across
    filesystems.  Returns true on success and false on failure.
    """
    #print "copyfile(" + src + "," + dest + "," + str(newmtime) + "," + str(sstat) + ")"
    try:
        if not sstat:
            sstat = os.lstat(src)
    except Exception as e:
        print("copyfile: Stating source file failed...", e)
        return False

    destexists = 1
    try:
        dstat = os.lstat(dest)
    except:
        dstat = os.lstat(os.path.dirname(dest))
        destexists = 0

    if destexists:
        if stat.S_ISLNK(dstat[stat.ST_MODE]):
            try:
                os.unlink(dest)
                destexists = 0
            except Exception as e:
                pass

    if stat.S_ISLNK(sstat[stat.ST_MODE]):
        try:
            target = os.readlink(src)
            if destexists and not stat.S_ISDIR(dstat[stat.ST_MODE]):
                os.unlink(dest)
            os.symlink(target, dest)
            #os.lchown(dest,sstat[stat.ST_UID],sstat[stat.ST_GID])
            return os.lstat(dest)
        except Exception as e:
            print("copyfile: failed to properly create symlink:", dest, "->", target, e)
            return False

    if stat.S_ISREG(sstat[stat.ST_MODE]):
        try:
            srcchown = False
            if not os.access(src, os.R_OK):
                # Make sure we can read it
                srcchown = True
                os.chmod(src, sstat[stat.ST_MODE] | stat.S_IRUSR)

            # For safety copy then move it over.
            shutil.copyfile(src, dest + "#new")
            os.rename(dest + "#new", dest)
        except Exception as e:
            print('copyfile: copy', src, '->', dest, 'failed.', e)
            return False
        finally:
            if srcchown:
                os.chmod(src, sstat[stat.ST_MODE])
                os.utime(src, (sstat[stat.ST_ATIME], sstat[stat.ST_MTIME]))

    else:
        #we don't yet handle special, so we need to fall back to /bin/mv
        a = getstatusoutput("/bin/cp -f " + "'" + src + "' '" + dest + "'")
        if a[0] != 0:
            print("copyfile: Failed to copy special file:" + src + "' to '" + dest + "'", a)
            return False # failure
    try:
        os.lchown(dest, sstat[stat.ST_UID], sstat[stat.ST_GID])
        os.chmod(dest, stat.S_IMODE(sstat[stat.ST_MODE])) # Sticky is reset on chown
    except Exception as e:
        print("copyfile: Failed to chown/chmod/unlink", dest, e)
        return False

    if newmtime:
        os.utime(dest, (newmtime, newmtime))
    else:
        os.utime(dest, (sstat[stat.ST_ATIME], sstat[stat.ST_MTIME]))
        newmtime = sstat[stat.ST_MTIME]
    return newmtime

def which(path, item, direction = 0):
    """
    Locate a file in a PATH
    """

    paths = (path or "").split(':')
    if direction != 0:
        paths.reverse()

    for p in paths:
        next = os.path.join(p, item)
        if os.path.exists(next):
            return next

    return ""

def to_boolean(string, default=None):
    if not string:
        return default

    normalized = string.lower()
    if normalized in ("y", "yes", "1", "true"):
        return True
    elif normalized in ("n", "no", "0", "false"):
        return False
    else:
        raise ValueError("Invalid value for to_boolean: %s" % string)

def contains(variable, checkvalues, truevalue, falsevalue, d):
    val = d.getVar(variable, True)
    if not val:
        return falsevalue
    val = set(val.split())
    if isinstance(checkvalues, basestring):
        checkvalues = set(checkvalues.split())
    else:
        checkvalues = set(checkvalues)
    if checkvalues.issubset(val): 
        return truevalue
    return falsevalue