"""The World — tile grid, building positions, message board, shell-lock
semaphore. Owns WorldState.

The map matches the user's sketch:
  - Cave (top-left)
  - Store / locker row (top-centre)
  - Well (top-right)
  - Town hall + message board (bottom-left)
  - Shell building + queue tile (bottom-right)

Tile coords are (col, row), origin top-left.

Movement is atomic: `move_to('cave')` puts the character onto a deterministic
stand-tile adjacent to the cave in one tick (CSS transition handles the
visual sweep). BFS pathing is gone — the LLM never reasons about coords.
"""

from __future__ import annotations

from dataclasses import dataclass, field

from .character import Character

GRID_W = 20
GRID_H = 12

# Named tile anchors. Building tiles are non-walkable; the LLM only ever
# names a place — code picks which adjacent tile the character stands on.
PLACES: dict[str, tuple[int, int]] = {
    "cave": (2, 1),
    "well": (17, 1),
    "town_hall": (3, 10),
    "shell": (16, 10),
    "shell_queue": (15, 10),
    "locker_row": (10, 1),
}

# Targets the LLM may pass to `move_to`. `shell_queue` is kept in PLACES
# as a coordinate anchor but is hidden from the move tool — agents reach
# the queue by trying to enter the shell while someone else holds the lock.
LLM_TARGETS: tuple[str, ...] = ("cave", "well", "locker_row", "town_hall", "shell")

BUILDING_TILES: set[tuple[int, int]] = {
    PLACES["cave"],
    PLACES["well"],
    PLACES["town_hall"],
    PLACES["shell"],
}

# Walkable tiles a character can stand on when at a named place. Order is
# stable; selection within the list is by hash(name) for deterministic per-
# character placement. Multiple chars at the same place may land on the
# same tile — z-index handles visual overlap, no functional impact.
STAND_TILES: dict[str, list[tuple[int, int]]] = {
    "cave":       [(1, 1), (3, 1), (2, 2)],
    "well":       [(16, 1), (17, 2), (18, 1)],
    "locker_row": [(9, 1), (11, 1), (10, 2)],
    "town_hall":  [(2, 10), (4, 10), (3, 9)],
    "shell":      [(15, 10), (17, 10), (16, 9), (16, 11)],
}


def stand_tile_for(place: str, character_name: str) -> tuple[int, int]:
    """Pick a stable stand-tile for `character_name` at `place`. Same
    character at the same place always lands on the same tile."""
    slots = STAND_TILES.get(place)
    if not slots:
        # Unknown place — fall back to PLACES coords if present.
        return PLACES.get(place, (1, 1))
    return slots[hash(character_name) % len(slots)]


def location_of(pos: tuple[int, int]) -> str:
    """Return the named place this position is at (one of the stand-tiles)
    or "wandering" if the position isn't a recognised stand-tile."""
    for place, slots in STAND_TILES.items():
        if tuple(pos) in {tuple(s) for s in slots}:
            return place
    return "wandering"


@dataclass
class BoardPost:
    author: str
    text: str
    tick: int


@dataclass
class ShellLine:
    author: str
    kind: str  # "in" | "out" | "err" | "system"
    text: str
    tick: int


@dataclass
class WorldState:
    tick: int = 0
    characters: dict[str, Character] = field(default_factory=dict)
    board: list[BoardPost] = field(default_factory=list)
    shell_lines: list[ShellLine] = field(default_factory=list)
    shell_lock_holder: str | None = None
    shell_queue: list[str] = field(default_factory=list)
    board_sentiment: str = "neutral"  # "positive" | "neutral" | "negative"
    paused: bool = False


def in_bounds(pos: tuple[int, int]) -> bool:
    x, y = pos
    return 0 <= x < GRID_W and 0 <= y < GRID_H


def is_walkable(pos: tuple[int, int]) -> bool:
    return in_bounds(pos) and pos not in BUILDING_TILES


def resolve_place(name: str) -> tuple[int, int] | None:
    return PLACES.get(name)


def at_place(pos: tuple[int, int], place: str) -> bool:
    """True if `pos` is one of the named place's stand-tiles. Used by action
    guards (mine_coal must be `at_place(pos, 'cave')`, etc.). Since
    movement is now atomic via `stand_tile_for`, this is equivalent to
    `location_of(pos) == place`, but the function survives in this name for
    clarity at the call site."""
    slots = STAND_TILES.get(place)
    if not slots:
        return False
    return tuple(pos) in {tuple(s) for s in slots}