"""One-time codes: single use, short redemption window, capped capability."""

import time
import unittest

from sigil import errors, sessions, viewcodes
from sigil.store import Store
from sigil import identity, keys


class Base(unittest.TestCase):
    def setUp(self):
        self.store = Store(":memory:")
        _, public = keys.generate()
        secret = identity.seed_bootstrap(self.store, "bigpickle")
        identity.enrol(
            self.store, "bigpickle", keys.export_public_b64(public), secret
        )


class TestIssueCodes(Base):
    def test_issue_returns_code_and_two_lifetimes(self):
        issued = viewcodes.issue_code(self.store, "bigpickle")
        self.assertIn("-", issued["code"])
        self.assertEqual(len(issued["code"].replace("-", "")), 8)
        # the code window is strictly shorter than the session window
        self.assertLess(issued["code_ttl"], issued["view_ttl"])
        self.assertLess(issued["redeem_expires_at"], issued["session_expires_at"])

    def test_code_ttl_must_be_shorter_than_view_ttl(self):
        with self.assertRaises(errors.SigilError):
            viewcodes.issue_code(
                self.store, "bigpickle", code_ttl=3600, view_ttl=60
            )

    def test_cannot_issue_code_with_write_scope(self):
        with self.assertRaises(errors.ScopeDenied):
            viewcodes.issue_code(self.store, "bigpickle", scopes=["view:write"])

    def test_cannot_issue_code_for_unknown_agent(self):
        with self.assertRaises(errors.UnknownAgent):
            viewcodes.issue_code(self.store, "ghost")

    def test_codes_are_distinct(self):
        codes = {viewcodes.issue_code(self.store, "bigpickle")["code"]
                 for _ in range(25)}
        self.assertEqual(len(codes), 25)

    def test_code_alphabet_has_no_ambiguous_characters(self):
        for _ in range(200):
            code = viewcodes.issue_code(self.store, "bigpickle")["code"]
            self.assertNotIn("0", code)
            self.assertNotIn("O", code)
            self.assertNotIn("1", code)
            self.assertNotIn("I", code)


class TestRedeemCodes(Base):
    def test_happy_path(self):
        issued = viewcodes.issue_code(self.store, "bigpickle")
        view = viewcodes.redeem_code(self.store, issued["code"])
        self.assertEqual(view["kind"], "human_via_agent")
        self.assertEqual(view["on_behalf_of"], "bigpickle")

    def test_code_is_single_use(self):
        issued = viewcodes.issue_code(self.store, "bigpickle")
        viewcodes.redeem_code(self.store, issued["code"])
        with self.assertRaises(errors.CodeUsed):
            viewcodes.redeem_code(self.store, issued["code"])

    def test_expired_code_refused(self):
        issued = viewcodes.issue_code(self.store, "bigpickle", code_ttl=1, view_ttl=600)
        time.sleep(1.2)
        with self.assertRaises(errors.CodeExpired):
            viewcodes.redeem_code(self.store, issued["code"])

    def test_unknown_code_refused(self):
        with self.assertRaises(errors.CodeInvalid):
            viewcodes.redeem_code(self.store, "ZZZZ-ZZZZ")

    def test_code_is_case_and_space_insensitive(self):
        issued = viewcodes.issue_code(self.store, "bigpickle")
        mangled = issued["code"].lower().replace("-", " ")
        view = viewcodes.redeem_code(self.store, mangled)
        self.assertEqual(view["on_behalf_of"], "bigpickle")

    def test_expired_code_grants_no_session(self):
        issued = viewcodes.issue_code(self.store, "bigpickle", code_ttl=1, view_ttl=600)
        time.sleep(1.2)
        before = len(self.store.sessions())
        with self.assertRaises(errors.CodeExpired):
            viewcodes.redeem_code(self.store, issued["code"])
        self.assertEqual(len(self.store.sessions()), before)

    def test_session_outlives_the_code_window(self):
        """The point of splitting the lifetimes: after the code dies the
        session it opened is still good."""
        issued = viewcodes.issue_code(self.store, "bigpickle", code_ttl=1, view_ttl=600)
        view = viewcodes.redeem_code(self.store, issued["code"])
        time.sleep(1.2)
        session = sessions.resolve(self.store, view["token"])
        self.assertEqual(session["kind"], "human_via_agent")


class TestAuditTrail(Base):
    def test_issue_and_redeem_are_recorded(self):
        issued = viewcodes.issue_code(self.store, "bigpickle")
        viewcodes.redeem_code(self.store, issued["code"])
        kinds = [e["kind"] for e in self.store.events(limit=50)]
        self.assertIn("view_code.issued", kinds)
        self.assertIn("view_code.redeemed", kinds)

    def test_human_appears_as_a_human_in_the_log(self):
        issued = viewcodes.issue_code(self.store, "bigpickle")
        viewcodes.redeem_code(self.store, issued["code"])
        redemption = [e for e in self.store.events(limit=50)
                      if e["kind"] == "view_code.redeemed"][0]
        self.assertEqual(redemption["subject"], "bigpickle's human")

    def test_replay_attempt_is_recorded(self):
        issued = viewcodes.issue_code(self.store, "bigpickle")
        viewcodes.redeem_code(self.store, issued["code"])
        with self.assertRaises(errors.CodeUsed):
            viewcodes.redeem_code(self.store, issued["code"])
        kinds = [e["kind"] for e in self.store.events(limit=50)]
        self.assertIn("view_code.redeem_refused", kinds)

    def test_replay_attempt_never_names_the_code(self):
        issued = viewcodes.issue_code(self.store, "bigpickle")
        viewcodes.redeem_code(self.store, issued["code"])
        with self.assertRaises(errors.CodeUsed):
            viewcodes.redeem_code(self.store, issued["code"])
        blob = repr(self.store.events(limit=50))
        self.assertNotIn(issued["code"], blob)

    def test_secret_is_never_stored_in_the_clear(self):
        fresh = Store(":memory:")
        secret = identity.seed_bootstrap(fresh, "bigpickle")
        _, public = keys.generate()
        identity.enrol(fresh, "bigpickle", keys.export_public_b64(public), secret)
        blob = repr(fresh.events(limit=100))
        self.assertNotIn(secret, blob)


if __name__ == "__main__":
    unittest.main()