"""TDD for spaceutil.deck.build_deck.

Hard invariants the builder must always satisfy:
  - Total quantity is exactly 50.
  - Every card shares at least one color with the leader.
  - No card has more than `max_copies` (default 4).
  - The leader itself is never in the main deck.
  - No other Leader cards are in the main deck.

Soft invariants (style behaviour):
  - Aggro decks have lower average cost than midrange.
  - Control decks have higher average cost than midrange.
"""

from __future__ import annotations

import numpy as np
import pytest


def _matrix(cards):
    return np.stack(
        [np.asarray(c["embedding"], dtype=np.float32) for c in cards], axis=0
    )


def _strip_emb(cards):
    return [{k: v for k, v in c.items() if k != "embedding"} for c in cards]


def _first_leader_idx(cards):
    return next(i for i, c in enumerate(cards) if c["card_type"] == "Leader")


class TestDeckSize:
    def test_total_quantity_is_50(self, synthetic_cards):
        from spaceutil.deck import build_deck

        idx = _first_leader_idx(synthetic_cards)
        matrix = _matrix(synthetic_cards)
        cards = _strip_emb(synthetic_cards)
        deck = build_deck(idx, cards, matrix, style="midrange")
        assert deck.total_quantity == 50

    def test_total_quantity_is_50_for_each_style(self, synthetic_cards):
        from spaceutil.deck import build_deck

        idx = _first_leader_idx(synthetic_cards)
        matrix = _matrix(synthetic_cards)
        cards = _strip_emb(synthetic_cards)
        for style in ("aggro", "midrange", "control"):
            deck = build_deck(idx, cards, matrix, style=style)
            assert deck.total_quantity == 50, f"{style} produced {deck.total_quantity}"


class TestColorLegality:
    def test_all_cards_share_a_color_with_leader(self, synthetic_cards):
        from spaceutil.deck import build_deck

        idx = _first_leader_idx(synthetic_cards)
        leader_colors = set(synthetic_cards[idx]["colors"])
        matrix = _matrix(synthetic_cards)
        cards = _strip_emb(synthetic_cards)
        deck = build_deck(idx, cards, matrix, style="midrange")

        for dc in deck.cards:
            assert set(dc.colors) & leader_colors, (
                f"{dc.card_id} has {dc.colors}, leader has {leader_colors}"
            )


class TestCopyLimit:
    def test_no_card_exceeds_max_copies_default(self, synthetic_cards):
        from spaceutil.deck import build_deck

        idx = _first_leader_idx(synthetic_cards)
        matrix = _matrix(synthetic_cards)
        cards = _strip_emb(synthetic_cards)
        deck = build_deck(idx, cards, matrix, style="midrange")

        for dc in deck.cards:
            assert 1 <= dc.quantity <= 4

    def test_no_card_exceeds_max_copies_explicit(self, synthetic_cards):
        from spaceutil.deck import build_deck

        idx = _first_leader_idx(synthetic_cards)
        matrix = _matrix(synthetic_cards)
        cards = _strip_emb(synthetic_cards)
        deck = build_deck(idx, cards, matrix, style="midrange", max_copies=2)

        assert deck.total_quantity == 50
        for dc in deck.cards:
            assert 1 <= dc.quantity <= 2


class TestLeaderExclusion:
    def test_other_leaders_not_in_deck(self, synthetic_cards):
        from spaceutil.deck import build_deck

        idx = _first_leader_idx(synthetic_cards)
        matrix = _matrix(synthetic_cards)
        cards = _strip_emb(synthetic_cards)
        deck = build_deck(idx, cards, matrix, style="midrange")

        for dc in deck.cards:
            assert dc.card_type != "Leader"

    def test_chosen_leader_not_in_main_deck(self, synthetic_cards):
        from spaceutil.deck import build_deck

        idx = _first_leader_idx(synthetic_cards)
        leader_id = synthetic_cards[idx]["id"]
        matrix = _matrix(synthetic_cards)
        cards = _strip_emb(synthetic_cards)
        deck = build_deck(idx, cards, matrix, style="midrange")

        for dc in deck.cards:
            assert dc.card_id != leader_id

    def test_raises_when_index_is_not_leader(self, synthetic_cards):
        from spaceutil.deck import build_deck

        non_leader_idx = next(
            i for i, c in enumerate(synthetic_cards) if c["card_type"] != "Leader"
        )
        matrix = _matrix(synthetic_cards)
        cards = _strip_emb(synthetic_cards)
        with pytest.raises(ValueError, match="not a Leader"):
            build_deck(non_leader_idx, cards, matrix)


class TestDeckMetadata:
    def test_deck_carries_leader_reference(self, synthetic_cards):
        from spaceutil.deck import build_deck

        idx = _first_leader_idx(synthetic_cards)
        leader_id = synthetic_cards[idx]["id"]
        matrix = _matrix(synthetic_cards)
        cards = _strip_emb(synthetic_cards)
        deck = build_deck(idx, cards, matrix, style="midrange")

        assert deck.leader["id"] == leader_id
        assert deck.style == "midrange"

    def test_avg_cost_computed(self, synthetic_cards):
        from spaceutil.deck import build_deck

        idx = _first_leader_idx(synthetic_cards)
        matrix = _matrix(synthetic_cards)
        cards = _strip_emb(synthetic_cards)
        deck = build_deck(idx, cards, matrix, style="midrange")

        assert deck.avg_cost > 0
        # 1-9 cost spread, midrange should land somewhere reasonable
        assert 1.5 < deck.avg_cost < 8.0


class TestStyleSensitivity:
    def test_aggro_cheaper_than_midrange(self, synthetic_cards):
        from spaceutil.deck import build_deck

        idx = _first_leader_idx(synthetic_cards)
        matrix = _matrix(synthetic_cards)
        cards = _strip_emb(synthetic_cards)
        aggro = build_deck(idx, cards, matrix, style="aggro")
        midrange = build_deck(idx, cards, matrix, style="midrange")

        assert aggro.avg_cost < midrange.avg_cost, (
            f"aggro avg {aggro.avg_cost:.2f} not < midrange {midrange.avg_cost:.2f}"
        )

    def test_control_pricier_than_midrange(self, synthetic_cards):
        from spaceutil.deck import build_deck

        idx = _first_leader_idx(synthetic_cards)
        matrix = _matrix(synthetic_cards)
        cards = _strip_emb(synthetic_cards)
        midrange = build_deck(idx, cards, matrix, style="midrange")
        control = build_deck(idx, cards, matrix, style="control")

        assert control.avg_cost > midrange.avg_cost, (
            f"control avg {control.avg_cost:.2f} not > midrange {midrange.avg_cost:.2f}"
        )

    def test_unknown_style_raises(self, synthetic_cards):
        from spaceutil.deck import build_deck

        idx = _first_leader_idx(synthetic_cards)
        matrix = _matrix(synthetic_cards)
        cards = _strip_emb(synthetic_cards)
        with pytest.raises(ValueError, match="style"):
            build_deck(idx, cards, matrix, style="bogus")


class TestExport:
    def test_to_text_format(self, synthetic_cards):
        from spaceutil.deck import build_deck, deck_to_text

        idx = _first_leader_idx(synthetic_cards)
        matrix = _matrix(synthetic_cards)
        cards = _strip_emb(synthetic_cards)
        deck = build_deck(idx, cards, matrix, style="midrange")
        text = deck_to_text(deck)

        assert deck.leader["id"] in text
        assert deck.leader["name"] in text
        for dc in deck.cards:
            assert f"{dc.quantity}x {dc.card_id}" in text
        # Sanity: at least one section header so it's human-readable
        assert "Leader" in text and "Main deck" in text

    def test_to_text_total_quantity_in_summary(self, synthetic_cards):
        from spaceutil.deck import build_deck, deck_to_text

        idx = _first_leader_idx(synthetic_cards)
        matrix = _matrix(synthetic_cards)
        cards = _strip_emb(synthetic_cards)
        deck = build_deck(idx, cards, matrix, style="midrange")
        text = deck_to_text(deck)

        assert "50" in text