"""Unit tests for the RPG world-state engine (Phase 12): delta extraction and
the code that enforces clamp, cooldown, and milestone rules.

    python -m pytest tests/test_worldstate.py -v
"""
from app import worldstate as w

SCHEMA = {
    "world": {"day": {"type": "counter", "min": 1, "initial": 1}},
    "player": {
        "hp": {"min": 0, "max": 100, "initial": 100, "max_delta_per_turn": 30,
               "bands": [[0, 20, "very weak"], [20, 40, "hurt"],
                         [40, 60, "minor damage"], [60, 90, "healthy"],
                         [90, 100, "full health"]]},
        "outfit": {"type": "text", "initial": "traveling clothes", "desc": "What the player is wearing"},
    },
    "npcs": {
        "gwen": {
            "name": "Gwen",
            "keys": "Gwen, ranger",
            "desc": "A loyal ranger",
            "stats": {"trust": {"min": -100, "max": 100, "initial": 0, "cooldown": 2}},
        },
        "drake": {
            "name": "The Drake",
            "stats": {"ferocity": {"min": 0, "max": 100, "initial": 50}},
        },
    },
    "flags": {
        "has_key": {"desc": "Holds the key", "initial": False},
        "disguised": {"desc": "In disguise"},
    },
    "milestones": {"rescue_gwen": {"desc": "Rescue Gwen"}},
}


def fresh():
    return w.instantiate(SCHEMA)


def test_instantiate_uses_initials():
    ws = fresh()
    assert ws["world"] == {"day": 1}
    assert ws["player"] == {"hp": 100, "outfit": "traveling clothes"}
    # Each defined NPC is instantiated up front with its own stats.
    assert ws["npc"] == {"gwen": {"trust": 0}, "drake": {"ferocity": 50}}
    assert ws["milestones"] == {}


def test_text_stat_replaces_value():
    ws, report = w.apply_delta(fresh(), SCHEMA, {"player.outfit": "muddy cloak"}, 1)
    assert ws["player"]["outfit"] == "muddy cloak"
    assert report["applied"][0] == {"path": "player.outfit", "old": "traveling clothes", "new": "muddy cloak"}


def test_text_stat_rejects_non_string():
    ws, report = w.apply_delta(fresh(), SCHEMA, {"player.outfit": 5}, 1)
    assert ws["player"]["outfit"] == "traveling clothes"
    assert report["rejected"][0]["reason"] == "not a string"


def test_text_stat_noop_when_unchanged():
    ws, report = w.apply_delta(fresh(), SCHEMA, {"player.outfit": "traveling clothes"}, 1)
    assert report["applied"] == []


def test_per_npc_distinct_stats():
    ws, _ = w.apply_delta(fresh(), SCHEMA, {"npc.drake.ferocity": 20}, 1)
    assert ws["npc"]["drake"]["ferocity"] == 70
    # gwen has no `ferocity` stat, and drake has no `trust` stat. Cross paths
    # are rejected.
    ws, report = w.apply_delta(ws, SCHEMA, {"npc.gwen.ferocity": 5, "npc.bogus.trust": 5}, 2)
    reasons = {r["reason"] for r in report["rejected"]}
    assert reasons == {"unknown npc stat", "unknown npc"}


def test_has_schema():
    assert w.has_schema(SCHEMA)
    assert not w.has_schema(None)
    assert not w.has_schema({})
    assert not w.has_schema({"npc_card_types": ["npc"]})  # config only, no stats


def test_max_delta_per_turn_clamps():
    ws, report = w.apply_delta(fresh(), SCHEMA, {"player.hp": -50}, 5)
    assert ws["player"]["hp"] == 70  # -50 capped to -30
    assert report["clamped"]


def test_clamp_to_min():
    ws, _ = w.apply_delta(fresh(), SCHEMA, {"player.hp": -30}, 1)
    ws, _ = w.apply_delta(ws, SCHEMA, {"player.hp": -30}, 3)
    ws, _ = w.apply_delta(ws, SCHEMA, {"player.hp": -30}, 5)
    ws, report = w.apply_delta(ws, SCHEMA, {"player.hp": -30}, 7)
    assert ws["player"]["hp"] == 0  # 100-30-30-30-30 clamps at min 0
    assert report["clamped"]


def test_counter_rejects_negative():
    ws, report = w.apply_delta(fresh(), SCHEMA, {"world.day": -1}, 3)
    assert ws["world"]["day"] == 1
    assert report["rejected"][0]["reason"] == "counter can't decrease"
    ws, _ = w.apply_delta(ws, SCHEMA, {"world.day": 1}, 4)
    assert ws["world"]["day"] == 2


def test_npc_cooldown():
    ws, _ = w.apply_delta(fresh(), SCHEMA, {"npc.gwen.trust": 10}, 7)
    assert ws["npc"]["gwen"]["trust"] == 10
    # cooldown 2: another change at index 8 is too soon.
    ws, report = w.apply_delta(ws, SCHEMA, {"npc.gwen.trust": 10}, 8)
    assert ws["npc"]["gwen"]["trust"] == 10
    assert report["rejected"][0]["reason"] == "cooldown"
    # far enough later, it applies.
    ws, _ = w.apply_delta(ws, SCHEMA, {"npc.gwen.trust": 10}, 10)
    assert ws["npc"]["gwen"]["trust"] == 20


def test_milestone_sticky():
    ws, report = w.apply_delta(fresh(), SCHEMA, {"milestones.rescue_gwen": True}, 9)
    assert ws["milestones"]["rescue_gwen"] == {"reached": True, "at": 9}
    assert report["applied"]
    # second set is a silent no-op.
    ws, report = w.apply_delta(ws, SCHEMA, {"milestones.rescue_gwen": True}, 11)
    assert ws["milestones"]["rescue_gwen"]["at"] == 9
    assert not report["applied"]
    # false is ignored.
    ws, report = w.apply_delta(ws, SCHEMA, {"milestones.rescue_gwen": False}, 13)
    assert ws["milestones"]["rescue_gwen"]["reached"] is True


def test_flags_toggle_both_ways():
    ws = fresh()
    assert ws["flags"] == {"has_key": False, "disguised": False}  # initials
    ws, report = w.apply_delta(ws, SCHEMA, {"flags.has_key": True}, 1)
    assert ws["flags"]["has_key"] is True
    assert report["applied"]
    # Setting it back to false works, because flags are two-way, unlike
    # sticky milestones.
    ws, _ = w.apply_delta(ws, SCHEMA, {"flags.has_key": False}, 2)
    assert ws["flags"]["has_key"] is False
    # setting to the same value is a no-op.
    ws, report = w.apply_delta(ws, SCHEMA, {"flags.has_key": False}, 3)
    assert not report["applied"]


def test_flag_rejects_non_bool_and_unknown():
    ws, report = w.apply_delta(fresh(), SCHEMA, {"flags.has_key": 1, "flags.nope": True}, 1)
    reasons = {r["reason"] for r in report["rejected"]}
    assert reasons == {"not a boolean", "unknown flag"}
    assert ws["flags"]["has_key"] is False


def test_override_sets_absolute_value_bypassing_cap():
    # A manual override does not obey max_delta_per_turn the way a turn
    # does. It sets the value directly, though the value is still clamped
    # to min/max.
    ws, report = w.apply_override(fresh(), SCHEMA, {"player.hp": 10})
    assert ws["player"]["hp"] == 10
    assert report["applied"] == [{"path": "player.hp", "old": 100, "new": 10}]
    ws, report = w.apply_override(ws, SCHEMA, {"player.hp": 999})
    assert ws["player"]["hp"] == 100  # still clamps to max


def test_override_bypasses_cooldown_and_counter_rule():
    ws, _ = w.apply_override(fresh(), SCHEMA, {"npc.gwen.trust": 10})
    # a second override immediately after would be blocked by cooldown under
    # apply_delta, but override ignores cooldown entirely.
    ws, report = w.apply_override(ws, SCHEMA, {"npc.gwen.trust": -5})
    assert ws["npc"]["gwen"]["trust"] == -5
    assert report["applied"]
    # counters can be set down directly too (a correction, not a turn).
    ws, report = w.apply_override(ws, SCHEMA, {"world.day": 1})
    assert ws["world"]["day"] == 1
    assert report["applied"]


def test_override_text_stat_replaces():
    ws, report = w.apply_override(fresh(), SCHEMA, {"player.outfit": "knight's plate"})
    assert ws["player"]["outfit"] == "knight's plate"
    assert report["applied"]


def test_override_milestone_toggles_both_ways():
    ws, _ = w.apply_override(fresh(), SCHEMA, {"milestones.rescue_gwen": True})
    assert ws["milestones"]["rescue_gwen"]["reached"] is True
    # unlike apply_delta, override can un-set a milestone.
    ws, report = w.apply_override(ws, SCHEMA, {"milestones.rescue_gwen": False})
    assert "rescue_gwen" not in ws["milestones"]
    assert report["applied"]


def test_override_rejects_unknown_and_bad_type():
    ws, report = w.apply_override(fresh(), SCHEMA, {
        "player.hp": "not a number",
        "npc.bogus.trust": 5,
        "flags.nope": True,
    })
    reasons = {r["path"]: r["reason"] for r in report["rejected"]}
    assert reasons["player.hp"] == "not a number"
    assert reasons["npc.bogus.trust"] == "unknown npc"
    assert reasons["flags.nope"] == "unknown flag"
    assert ws["player"]["hp"] == 100  # untouched


def test_reference_includes_desc_and_bands_independently():
    guide = w.render_reference(SCHEMA)
    # hp has both a description and a set of value bands.
    assert "very weak" in guide and "range 0–100" in guide
    # A counter like day has no desc or bands, so it contributes nothing
    # here. Flags do show their desc.
    assert "flags.has_key — Holds the key." in guide
    # NPCs contribute their own description and per-NPC stat lines.
    assert "NPC Gwen (npc.gwen) — A loyal ranger." in guide
    assert "npc.gwen.trust" in guide and "npc.drake.ferocity" in guide


def test_reference_names_every_stat_by_its_path():
    """The guide is the model's only complete list of what exists, so it has
    to name each stat the way a state block must name it. Naming a stat after
    its owner's display name ("Trainer Milo active_status") left the model to
    build the path itself, and the paths it built were refused as stats and
    characters that do not exist."""
    guide = w.render_reference(SCHEMA)
    assert "player.hp" in guide
    assert "player.outfit" in guide
    # The old wording, which read as prose rather than as an address.
    assert "Gwen trust" not in guide
    assert "The Drake ferocity" not in guide


def test_reference_names_an_npc_that_has_no_description():
    """The live values name an NPC only while a scene mentions them, so the
    guide is the only place an off-screen NPC's id is stated. The Drake has no
    `desc`, and used to reach the model as "The Drake ferocity" alone."""
    guide = w.render_reference(SCHEMA)
    assert "NPC The Drake (npc.drake)." in guide


def test_reference_marks_free_text_stats_the_way_the_emit_rule_names_them():
    """`EMIT_RULE` tells the model that a stat "marked (free text) in the stat
    guide" takes a whole value rather than a delta, so the guide has to carry
    that marker literally."""
    assert "(free text)" in w.EMIT_RULE
    guide = w.render_reference(SCHEMA)
    assert "player.outfit (free text) — What the player is wearing." in guide


def test_reference_lists_a_free_text_stat_with_no_description():
    """The marker alone is the entry. Dropping the line would leave the model
    sending a number for a stat that holds a string."""
    schema = {"player": {"holding": {"type": "text", "initial": ""}}}
    assert "player.holding (free text)." in w.render_reference(schema)


def test_unknown_paths_rejected_not_fatal():
    ws, report = w.apply_delta(fresh(), SCHEMA, {"player.stamina": -5, "bogus": 1}, 2)
    reasons = {r["reason"] for r in report["rejected"]}
    assert reasons == {"unknown stat", "unknown path"}
    assert ws["player"]["hp"] == 100  # untouched


def test_extract_fenced_delta_tolerates_mess():
    text = 'You strike.\n\n```state\n{"player.hp": -15, "npc.12.trust": +5,}\n```'
    clean, delta = w.extract_delta(text)
    assert clean == "You strike."
    assert delta == {"player.hp": -15, "npc.12.trust": 5}


def test_extract_no_block():
    clean, delta = w.extract_delta("Just prose that ends normally.")
    assert delta == {}
    assert clean == "Just prose that ends normally."


def test_extract_prose_ending_in_brace_not_eaten():
    # A bare object with no dotted keys is not a delta, so the text stays
    # as is.
    clean, delta = w.extract_delta('He said {this}')
    assert delta == {}
    assert clean == "He said {this}"


def test_band_label():
    d = SCHEMA["player"]["hp"]
    assert w.band_label(d, 10) == "very weak"
    assert w.band_label(d, 55) == "minor damage"
    assert w.band_label(d, 100) == "full health"  # inclusive top edge


def test_render_delta_block_roundtrips_through_extract():
    # A rendered block re-injected into history must parse back to the same delta,
    # so the model sees valid examples of its own emit format.
    delta = {"player.hp": -15, "milestones.escaped": True}
    block = w.render_delta_block(delta)
    assert block.startswith("```state")
    clean, parsed = w.extract_delta(f"You flee into the night.\n{block}")
    assert clean == "You flee into the night."
    assert parsed == delta


def test_render_delta_block_empty_is_blank():
    # No change this turn -> nothing appended to history.
    assert w.render_delta_block({}) == ""
    assert w.render_delta_block(None) == ""