"""Initiative tracker: pure state functions, quick-add parsing, rendering.

No AI, no network, no external dependencies. State is a plain JSON-safe
dict so it round-trips cleanly through gr.BrowserState (localStorage):

    {"round": 1, "turn_index": 0,
     "entries": [{"id": 1, "name": "Kira", "initiative": 18.0, "is_pc": True}]}

Every mutation returns a NEW state dict; callers never mutate in place.
The only randomness is the d20 rolls the user asks for (Python's random).
"""

import html as _html
import random
import re

_MOD_RE = re.compile(r"^[+-]\d+$")
_NUM_RE = re.compile(r"^-?\d+(\.\d+)?$")
_COUNT_RE = re.compile(r"^[xX](\d+)$")

MAX_NAME = 60
MAX_ENTRIES = 100
MAX_COUNT = 20  # cap "Name xN" so a stray "x999" can't flood the list


# ---------------------------------------------------------------- state core

def new_state() -> dict:
    return {"round": 1, "turn_index": 0, "entries": []}


def coerce_state(raw) -> dict:
    """Defensively rebuild a state dict (e.g. from localStorage)."""
    if not isinstance(raw, dict):
        return new_state()
    entries = []
    for e in raw.get("entries", []) if isinstance(raw.get("entries"), list) else []:
        if not isinstance(e, dict):
            continue
        name = str(e.get("name", "")).strip()[:MAX_NAME]
        if not name:
            continue
        try:
            initiative = float(e.get("initiative", 0))
        except (TypeError, ValueError):
            initiative = 0.0
        entries.append({
            "id": int(e.get("id", 0)) or (max((x["id"] for x in entries), default=0) + 1),
            "name": name,
            "initiative": initiative,
            "is_pc": bool(e.get("is_pc", False)),
        })
        if len(entries) >= MAX_ENTRIES:
            break
    try:
        rnd = max(1, int(raw.get("round", 1)))
    except (TypeError, ValueError):
        rnd = 1
    try:
        ti = int(raw.get("turn_index", 0))
    except (TypeError, ValueError):
        ti = 0
    if not (0 <= ti < len(entries)):
        ti = 0
    return {"round": rnd, "turn_index": ti, "entries": entries}


def _next_id(entries) -> int:
    return max((e["id"] for e in entries), default=0) + 1


def _current_id(state):
    entries = state["entries"]
    if entries and 0 <= state["turn_index"] < len(entries):
        return entries[state["turn_index"]]["id"]
    return None


def _index_of(entries, eid):
    for i, e in enumerate(entries):
        if e["id"] == eid:
            return i
    return None


def _with_entries(state, entries, prefer_current_id=None) -> dict:
    """New state with `entries`, keeping the highlighted combatant if possible."""
    ti = 0
    if prefer_current_id is not None:
        idx = _index_of(entries, prefer_current_id)
        if idx is not None:
            ti = idx
    if not (0 <= ti < len(entries)):
        ti = 0
    return {"round": state["round"], "turn_index": ti, "entries": entries}


# ------------------------------------------------------------- add / remove

def add_entry(state, name, initiative, is_pc=False) -> dict:
    name = str(name or "").strip()[:MAX_NAME]
    if not name or len(state["entries"]) >= MAX_ENTRIES:
        return state
    entry = {
        "id": _next_id(state["entries"]),
        "name": name,
        "initiative": float(initiative),
        "is_pc": bool(is_pc),
    }
    entries = sorted(
        state["entries"] + [entry], key=lambda e: -float(e["initiative"])
    )
    return _with_entries(state, entries, prefer_current_id=_current_id(state))


def _parse_line(line, roll_for_blank):
    """One quick-add line -> (list of (name, initiative, is_pc), messages)."""
    tokens = line.split()
    count = 1
    count_idx = next(
        (i for i, t in enumerate(tokens) if _COUNT_RE.match(t)), None
    )
    if count_idx is not None:
        count = min(max(1, int(_COUNT_RE.match(tokens[count_idx]).group(1))),
                    MAX_COUNT)
        tokens = tokens[:count_idx] + tokens[count_idx + 1:]

    suffix = None
    if len(tokens) >= 2 and (_MOD_RE.match(tokens[-1]) or _NUM_RE.match(tokens[-1])):
        suffix = tokens[-1]
        tokens = tokens[:-1]
    name = " ".join(tokens).strip()
    if not name:
        return [], []

    specs, messages = [], []
    for i in range(1, count + 1):
        ename = name if count == 1 else f"{name} {i}"
        if suffix is not None and _MOD_RE.match(suffix):
            mod = int(suffix)
            total = random.randint(1, 20) + mod
            mod_txt = f"+{mod}" if mod >= 0 else str(mod)
            specs.append((ename, float(total), False))
            messages.append(f"{ename} rolled {total} (d20{mod_txt})")
        elif suffix is not None:
            # An explicit total: typically a player calling out their roll.
            specs.append((ename, float(suffix), True))
        elif roll_for_blank:
            roll = random.randint(1, 20)
            specs.append((ename, float(roll), False))
            messages.append(f"{ename} rolled {roll} (d20)")
        else:
            specs.append((ename, 0.0, False))
    return specs, messages


def quick_add(state, text, roll_for_blank=True):
    """Parse flexible quick-entry lines. Returns (new_state, messages).

    Supported per line:  "Kira 18"  |  "Torvin +2"  |  "Shadow"  |  "Goblin x3 +2"
    """
    messages = []
    st = state
    for raw in (text or "").splitlines():
        line = raw.strip()
        if not line:
            continue
        specs, msgs = _parse_line(line, roll_for_blank)
        for name, initiative, is_pc in specs:
            if len(st["entries"]) >= MAX_ENTRIES:
                messages.append(f"Entry limit reached ({MAX_ENTRIES}).")
                return st, messages
            st = add_entry(st, name, initiative, is_pc=is_pc)
        messages.extend(msgs)
    return st, messages


def remove_entry(state, eid) -> dict:
    idx = _index_of(state["entries"], eid)
    if idx is None:
        return state
    entries = [e for e in state["entries"] if e["id"] != eid]
    ti = state["turn_index"]
    if idx < ti:
        ti -= 1
    if not (0 <= ti < len(entries)):
        ti = 0
    return {"round": state["round"], "turn_index": ti, "entries": entries}


# ---------------------------------------------------------- manual reorder

def _swap(state, eid, offset) -> dict:
    idx = _index_of(state["entries"], eid)
    if idx is None:
        return state
    j = idx + offset
    if not (0 <= j < len(state["entries"])):
        return state  # clamp at edges
    entries = list(state["entries"])
    entries[idx], entries[j] = entries[j], entries[idx]
    return _with_entries(state, entries, prefer_current_id=_current_id(state))


def move_up(state, eid) -> dict:
    return _swap(state, eid, -1)


def move_down(state, eid) -> dict:
    return _swap(state, eid, 1)


# ------------------------------------------------------------- turn cycling

def next_turn(state) -> dict:
    n = len(state["entries"])
    if n == 0:
        return state
    ti = state["turn_index"] + 1
    if ti >= n:
        return {"round": state["round"] + 1, "turn_index": 0,
                "entries": state["entries"]}
    return {"round": state["round"], "turn_index": ti,
            "entries": state["entries"]}


def prev_turn(state) -> dict:
    n = len(state["entries"])
    if n == 0:
        return state
    if state["turn_index"] > 0:
        return {"round": state["round"], "turn_index": state["turn_index"] - 1,
                "entries": state["entries"]}
    if state["round"] > 1:
        return {"round": state["round"] - 1, "turn_index": n - 1,
                "entries": state["entries"]}
    return state


def reset_rounds(state) -> dict:
    return {"round": 1, "turn_index": 0, "entries": list(state["entries"])}


def clear_all() -> dict:
    return new_state()


# ---------------------------------------------------------------- rendering

def _fmt_init(value) -> str:
    f = float(value)
    return str(int(f)) if f == int(f) else f"{f:g}"


def render_list(state) -> str:
    """HTML ordered list: current turn highlighted, PCs tagged, values shown."""
    entries = state["entries"]
    if not entries:
        return (
            '<div class="lf-page"><p><em>No combatants yet — paste names in '
            "the quick-add box and hit Add to Order.</em></p></div>"
        )
    base_li = (
        "display:flex;align-items:center;gap:0.6rem;background:var(--lf-panel);"
        "border-radius:8px;padding:0.6rem 0.9rem;margin:0.4rem 0;"
        "color:var(--lf-cream);"
    )
    items = []
    for i, e in enumerate(entries):
        current = i == state["turn_index"]
        border = (
            "border:2px solid var(--lf-gold);" if current
            else "border:1px solid rgba(212,175,55,0.35);"
        )
        marker = (
            '<span style="color:var(--lf-gold);font-weight:700;">&#9654;</span>'
            if current else '<span style="opacity:0;">&#9654;</span>'
        )
        pc_tag = (
            '<span style="font-size:0.72rem;font-weight:700;color:#21301F;'
            'background:var(--lf-gold);border-radius:4px;padding:0.1rem 0.4rem;">'
            "PC</span>" if e["is_pc"] else ""
        )
        items.append(
            f'<li style="{base_li}{border}">'
            f'<span style="opacity:0.7;min-width:1.4rem;">{i + 1}.</span>'
            f"{marker}"
            f"<span>{_html.escape(e['name'])}</span>{pc_tag}"
            f'<span style="margin-left:auto;font-weight:700;'
            f'color:var(--lf-gold);">{_fmt_init(e["initiative"])}</span>'
            "</li>"
        )
    return (
        '<div class="lf-page"><ol style="list-style:none;padding:0;'
        f'margin:0.5rem 0;">{"".join(items)}</ol></div>'
    )


def render_banner(state) -> str:
    if not state["entries"]:
        return (
            '<div class="lf-page"><p class="lf-tagline">Round 1 — add '
            "combatants to begin.</p></div>"
        )
    current = state["entries"][state["turn_index"]]
    return (
        '<div class="lf-page"><p class="lf-tagline" style="margin:0.25rem 0;">'
        f"Round {state['round']} — "
        f'<strong>{_html.escape(current["name"])}</strong> is up.</p></div>'
    )


def render_roll_log(messages) -> str:
    if not messages:
        return ""
    text = " &middot; ".join(_html.escape(m) for m in messages)
    return (
        '<p style="font-size:0.85rem;color:rgba(242,230,206,0.7);'
        f'margin:0.35rem 0 0 0;line-height:1.5;">{text}</p>'
    )


def export_text(state) -> str:
    """Plain-text numbered order with the round, ready to paste anywhere."""
    lines = [f"Initiative Order — Round {state['round']}"]
    if not state["entries"]:
        lines.append("(no combatants)")
    for i, e in enumerate(state["entries"], 1):
        marker = "> " if (i - 1) == state["turn_index"] else "  "
        pc = " (PC)" if e["is_pc"] else ""
        lines.append(f"{marker}{i}. {e['name']} — {_fmt_init(e['initiative'])}{pc}")
    return "\n".join(lines)