import rpm
import os

class Package:
    def __init__(self, name):
        self.name = name

class PackageSet:
    def __init__(self, path):
        self.pkgs, self.requires, self.provides = {}, {}, {}
        os.path.walk(path, PackageSet.__find_rpms, self)

        for pkg in self.pkgs.values():
            requires = {}
            for require in self.requires[pkg.name]:
                if self.provides.has_key(require):
                    if self.provides[require] == pkg.name:
                        continue
                    if self.provides[require] == "jpackage-utils":
                        continue
                    if self.provides[require] == "java-1.4.2-gcj-compat" and \
                       pkg.name not in ("java-1.4.2-gcj-compat-devel",
                                        "eclipse-ecj"):
                        continue
                    requires[self.provides[require]] = 1
                else:
                    assert is_ignorable(require)
            requires = requires.keys()
            requires.sort()
            pkg.requires = requires

    def __find_rpms(self, dir, items):
        for item in items:
            if item.endswith(".rpm") and not item.endswith(".src.rpm"):
                self.__add_rpm(os.path.join(dir, item))

    def __add_rpm(self, path):
        fd = os.open(path, os.O_RDONLY)
        try:
            hdr = rpm.TransactionSet().hdrFromFdno(fd)
        finally:
            os.close(fd)
        assert type(hdr) == rpm.hdr

        name = hdr["name"]
        assert not self.pkgs.has_key(name)
        self.pkgs[name] = Package(name)
        
        assert not self.requires.has_key(name)
        self.requires[name] = hdr["requirename"]
        if name in ("tomcat5", "tomcat5-jasper"):
            self.requires[name].remove("jakarta-commons-daemon")
        if name == "tomcat5":
            self.requires[name].append("puretls")

        for provide in hdr["providename"]:
            if (name, provide) == ("xerces-j2", "jaxp_parser_impl"):
                continue
            assert not self.provides.has_key(provide)
            self.provides[provide] = name

    def graph(self, start):
        nodes, edges = {}, []
        for node in start:
            nodes[node] = False
        while True:
            todo = [k for k, v in nodes.items() if not v]
            if not todo:
                break
            for name in todo:
                pkg = self.pkgs[name]
                for require in pkg.requires:
                    edges.append((name, require))
                    if not nodes.has_key(require):
                        nodes[require] = False
                nodes[name] = True
        return edges

def is_ignorable(dep):
    if dep.startswith("/"):
        return True
    if dep.startswith("rpmlib("):
        return True
    if dep.startswith("lib") and dep.find(".so") != -1:
        return True
    if dep in ("gcc-java", "gjdoc", "httpd-mmn", "libgcj", "libgcj-src"):
        return True
    return False

if __name__ == "__main__":
    import glob, sys
    [path] = glob.glob(os.path.join(os.path.split(
        os.path.abspath( sys.argv[0]))[0], "pkgs-*"))
    pkgs = PackageSet(path)

    print "// Runtime dependencies for FC4 Java stack"
    print "// dot -Tps graph.dot -o graph.ps"
    print
    print "digraph G {"
    print '    page="8.27, 11.69";'
    print '    ratio="fill";'
    for requirer, provider in pkgs.graph(
        ("tomcat5",
         "tomcat5-webapps",
         "tomcat5-admin-webapps",
         "avalon-logkit")):
        print '    "%s" -> "%s";' % (requirer, provider)
    print "}"