from __future__ import absolute_import, print_function

from edenscm.mercurial import util
from hghave import require


def printifpresent(d, xs, name="d"):
    for x in xs:
        present = x in d
        print("'%s' in %s: %s" % (x, name, present))
        if present:
            print("%s['%s']: %s" % (name, x, d[x]))


def test_lrucachedict():
    d = util.lrucachedict(4)
    d["a"] = "va"
    d["b"] = "vb"
    d["c"] = "vc"
    d["d"] = "vd"

    # all of these should be present
    printifpresent(d, ["a", "b", "c", "d"])

    # 'a' should be dropped because it was least recently used
    d["e"] = "ve"
    printifpresent(d, ["a", "b", "c", "d", "e"])

    assert d.get("a") is None
    assert d.get("e") == "ve"

    # touch entries in some order (get or set).
    d["e"]
    d["c"] = "vc2"
    d["d"]
    d["b"] = "vb2"

    # 'e' should be dropped now
    d["f"] = "vf"
    printifpresent(d, ["b", "c", "d", "e", "f"])

    d.clear()
    printifpresent(d, ["b", "c", "d", "e", "f"])

    # Now test dicts that aren't full.
    d = util.lrucachedict(4)
    d["a"] = 1
    d["b"] = 2
    d["a"]
    d["b"]
    printifpresent(d, ["a", "b"])

    # test copy method
    d = util.lrucachedict(4)
    d["a"] = "va3"
    d["b"] = "vb3"
    d["c"] = "vc3"
    d["d"] = "vd3"

    dc = d.copy()

    # all of these should be present
    print("\nAll of these should be present:")
    printifpresent(dc, ["a", "b", "c", "d"], "dc")

    # 'a' should be dropped because it was least recently used
    print("\nAll of these except 'a' should be present:")
    dc["e"] = "ve3"
    printifpresent(dc, ["a", "b", "c", "d", "e"], "dc")

    # contents and order of original dict should remain unchanged
    print("\nThese should be in reverse alphabetical order and read 'v?3':")
    dc["b"] = "vb3_new"
    for k in list(iter(d)):
        print("d['%s']: %s" % (k, d[k]))


if __name__ == "__main__":
    test_lrucachedict()