import os

from collections import defaultdict

class TreeNode(object):
    def __init__(self, parent = None):
        self.parent = parent
        self.children = defaultdict(lambda : TreeNode(self))
        self.values = []

class DirMap(object):
    def to_csv(self, vals):
        val_strs = []
        for key in sorted(vals.keys()):
            val_strs += ["%s=%s" % (key, vals[key])]
        return "%s.csv" % ("_".join(val_strs))

    def __init__(self):
        self.root = TreeNode(None)
        self.values  = []

    def add_value(self, path, value):
        node = self.root
        for p in path:
            node = node.children[p]
        node.values += [value]

    def reduce(self):
        def reduce2(node):
            for key in node.children.keys():
                child = node.children[key]
                reduce2(child)
                if not (child.children or child.values):
                    node.children.pop(key)

            if len(node.values) == 1:
                node.values = []

        reduce2(self.root)

    def write(self, out_dir):
        def write2(path, node):
            out_path = "/".join(path)
            if node.values:
                # Leaf
                with open("/".join(path), "w") as f:
                    arr = [",".join([str(b) for b in n]) for n in node.values]
                    f.write("\n".join(arr) + "\n")
            elif not os.path.isdir(out_path):
                os.mkdir(out_path)

            for (key, child) in node.children.iteritems():
                path.append(key)
                write2(path, child)
                path.pop()

        write2([out_dir], self.root)


    def __str__(self):
        def str2(node, level):
            header = "  " * level
            ret = ""
            if not node.children:
                return "%s%s\n" % (header, str(node.values) if node.values else "")
            for key,child in node.children.iteritems():
                ret += "%s/%s\n" % (header, key)
                ret += str2(child, level + 1)
            return ret
        return str2(self.root, 1)