/**
 * Activate HP history tracking that stores entries in flags only.
 * Pair with macro_enable-history-tab.js to view the data inside a History tab.
 */

const TARGET_ACTOR = game.actors.getName("Zeratal") ?? null;
const ACTOR_ID = TARGET_ACTOR?.id ?? "put-actor-id-here";
const HP_PATH = "system.attributes.hp.value";
const FLAG_SCOPE = "world";
const FLAG_KEY = "pf1HpHistory";
const UPDATE_CONTEXT_FLAG = "hpHistoryFlags";
const MAX_ROWS = 50;

if (!ACTOR_ID || ACTOR_ID === "put-actor-id-here") {
  return ui.notifications.warn("Set ACTOR_ID before running the macro.");
}

game.pf1 ??= {};
game.pf1.hpHistoryFlags ??= { sources: new Map(), current: {}, hooks: {} };
const state = game.pf1.hpHistoryFlags;

const logKey = `pf1-hp-history-flags-${ACTOR_ID}`;
if (state.hooks[logKey]) {
  Hooks.off("updateActor", state.hooks[logKey]);
  delete state.hooks[logKey];
}

ensureDamageSourceTracking();
primeSnapshot(game.actors.get(ACTOR_ID) ?? TARGET_ACTOR);

state.hooks[logKey] = Hooks.on("updateActor", (actor, change, options, userId) => {
  if (actor.id !== ACTOR_ID) return;
  if (options?.[UPDATE_CONTEXT_FLAG]) return;

  const newHP = readHpValue(actor);
  if (newHP === null) return;

  const previous = state.current[ACTOR_ID];
  if (previous === undefined) {
    state.current[ACTOR_ID] = newHP;
    return;
  }
  if (Object.is(newHP, previous)) return;

  const diff = newHP - previous;
  const diffText = diff >= 0 ? `+${diff}` : `${diff}`;
  const user = game.users.get(userId);
  const source = consumeDamageSource(actor.id) ?? inferManualSource(diff);

  state.current[ACTOR_ID] = newHP;

  appendHistoryEntry(actor, {
    hp: newHP,
    diff: diffText,
    user: user?.name ?? "System",
    source: source ?? "",
  }).catch((err) => console.error("HP History Flags | Failed to append entry", err));
});

const actorName = game.actors.get(ACTOR_ID)?.name ?? TARGET_ACTOR?.name ?? ACTOR_ID;
ui.notifications.info(`HP flag history tracking active for ${actorName}.`);

async function appendHistoryEntry(actor, entry) {
  const existing = (await actor.getFlag(FLAG_SCOPE, FLAG_KEY)) ?? [];
  existing.unshift({
    timestamp: Date.now(),
    hp: entry.hp,
    diff: entry.diff,
    user: entry.user,
    source: entry.source,
  });
  if (existing.length > MAX_ROWS) existing.splice(MAX_ROWS);

  await actor.setFlag(FLAG_SCOPE, FLAG_KEY, existing);
}

function consumeDamageSource(actorId) {
  const entry = state.sources.get(actorId);
  if (!entry) return null;
  state.sources.delete(actorId);
  return entry.label;
}

function inferManualSource(diff) {
  if (!Number.isFinite(diff) || diff === 0) return null;
  return diff > 0 ? "Manual healing" : "Manual damage";
}

function ensureDamageSourceTracking() {
  if (state.applyDamageWrapped) return;

  const ActorPF = pf1?.documents?.actor?.ActorPF;
  if (!ActorPF?.applyDamage) return;

  const original = ActorPF.applyDamage;
  ActorPF.applyDamage = async function wrappedApplyDamage(value, options = {}) {
    try {
      noteDamageSource(value, options);
    } catch (err) {
      console.warn("HP History Flags | Failed to record source", err);
    }
    return original.call(this, value, options);
  };

  state.applyDamageWrapped = true;
}

function noteDamageSource(value, options) {
  const actors = resolveActorTargets(options?.targets);
  if (!actors.some((a) => a?.id === ACTOR_ID)) return;

  const label = buildSourceLabel(value, options);
  if (!label) return;
  state.sources.set(ACTOR_ID, { label, ts: Date.now() });
}

function buildSourceLabel(value, options = {}) {
  const info = options.message?.flags?.pf1?.identifiedInfo ?? {};
  const metadata = options.message?.flags?.pf1?.metadata ?? {};
  const fromChatFlavor = options.message?.flavor?.trim();

  const actorDoc = resolveActorFromMetadata(metadata);
  const itemDoc = actorDoc ? resolveItemFromMetadata(actorDoc, metadata) : null;
  const actorName = actorDoc?.name ?? options.message?.speaker?.alias ?? null;
  const actionName = info.actionName ?? info.name ?? itemDoc?.name ?? fromChatFlavor ?? null;

  let label = null;
  if (actorName && actionName) label = `${actorName} -> ${actionName}`;
  else if (actionName) label = actionName;
  else if (actorName) label = actorName;
  else label = value < 0 ? "Healing" : "Damage";

  if (options.isCritical) label += " (Critical)";
  if (options.asNonlethal) label += " [Nonlethal]";

  return label;
}

function primeSnapshot(actor) {
  const hp = readHpValue(actor);
  if (hp === null) return;
  state.current[ACTOR_ID] = hp;
}

function resolveActorTargets(targets) {
  let list = [];
  if (Array.isArray(targets) && targets.length) list = targets;
  else list = canvas?.tokens?.controlled ?? [];

  return list
    .map((entry) => {
      if (!entry) return null;
      if (entry instanceof Actor) return entry;
      if (entry.actor) return entry.actor;
      if (entry.document?.actor) return entry.document.actor;
      return null;
    })
    .filter((actor) => actor instanceof Actor && actor.id);
}

function readHpValue(actor) {
  if (!actor) return null;

  const candidates = [
    HP_PATH,
    HP_PATH.replace(/^system\./, "data."),
    HP_PATH.replace(/^system\./, ""),
  ];

  for (const path of candidates) {
    const value = foundry.utils.getProperty(actor, path);
    if (value !== undefined) {
      const numeric = Number(value);
      return Number.isFinite(numeric) ? numeric : null;
    }
    if (actor.system) {
      const trimmed = path.startsWith("system.") ? path.slice(7) : path;
      const systemValue = foundry.utils.getProperty(actor.system, trimmed);
      if (systemValue !== undefined) {
        const numeric = Number(systemValue);
        return Number.isFinite(numeric) ? numeric : null;
      }
    }
  }

  return null;
}

function resolveActorFromMetadata(metadata = {}) {
  if (!metadata.actor) return null;

  if (typeof fromUuidSync === "function") {
    try {
      const doc = fromUuidSync(metadata.actor);
      if (doc instanceof Actor) return doc;
    } catch (err) {
      console.warn("HP History Flags | Failed to resolve actor UUID", err);
    }
  }

  const id = metadata.actor.split(".").pop();
  return game.actors.get(id) ?? null;
}

function resolveItemFromMetadata(actor, metadata = {}) {
  if (!metadata.item || !(actor?.items instanceof Collection)) return null;
  return actor.items.get(metadata.item) ?? null;
}