const pull = require("../server/node_modules/pull-stream");
const { getConfig } = require("../configs/config-manager.js");
const categories = require("../backend/opinion_categories");
const { buildValidatedTombstoneSet } = require('./tombstone_validator');
const { readTyped, memoIndex } = require('./typed_log');
const { dedupeBy, norm, versionGroups } = require('../backend/dedupe');

const logLimit = getConfig().ssbLogStream?.limit || 1000;

const safeArr = (v) => (Array.isArray(v) ? v : []);

const normalizeTags = (raw) => {
  if (raw === undefined || raw === null) return undefined;
  if (Array.isArray(raw)) return raw.map((t) => String(t || "").trim()).filter(Boolean);
  return String(raw).split(",").map((t) => t.trim()).filter(Boolean);
};

const parseBlobId = (blobMarkdown) => {
  const s = String(blobMarkdown || "");
  const match = s.match(/\(([^)]+)\)/);
  return match ? match[1] : s || null;
};

const voteSum = (opinions = {}) =>
  Object.values(opinions || {}).reduce((s, n) => s + (Number(n) || 0), 0);

module.exports = ({ cooler }) => {
  let ssb;

  const openSsb = async () => {
    if (!ssb) ssb = await cooler.open();
    return ssb;
  };

  const IMAGE_TYPES = ["image", "imageOpinion", "tombstone"];

  const getAllMessages = async (ssbClient) => readTyped(ssbClient, IMAGE_TYPES, { limit: logLimit });

  const getMsg = async (ssbClient, key) =>
    new Promise((resolve, reject) => {
      ssbClient.get(key, (err, msg) => (err ? reject(err) : resolve(msg)));
    });

  const buildIndex = (messages) => {
    const tomb = buildValidatedTombstoneSet(messages);
    const nodes = new Map();
    const opinionMsgs = [];

    for (const m of messages) {
      const k = m.key;
      const v = m.value || {};
      const c = v.content;
      if (!c) continue;

      if (c.type === "tombstone") continue;
      if (c.type === "imageOpinion") { opinionMsgs.push({ target: c.target, author: v.author, category: c.category }); continue; }
      if (c.type !== "image") continue;

      const ts = v.timestamp || m.timestamp || 0;
      let sizeBytes = 0;
      try { sizeBytes = Buffer.byteLength(JSON.stringify(v), "utf8"); } catch (_) { sizeBytes = 0; }
      nodes.set(k, { key: k, ts, seq: v.sequence || 0, c, sizeBytes, author: v.author });
    }

    const vg = versionGroups([...nodes.values()].map(n => ({ key: n.key, author: n.author, seq: n.seq, ts: n.ts, replaces: n.c.replaces || null, claimedAuthor: typeof n.c.author === "string" ? n.c.author : null })));
    const rootOf = vg.rootOf;
    const contentTipOf = vg.tipOf;

    const opinionsByRoot = new Map();
    for (const op of opinionMsgs) { if (!nodes.has(op.target)) continue; const r = rootOf(op.target); if (!opinionsByRoot.has(r)) opinionsByRoot.set(r, []); opinionsByRoot.get(r).push(op); }

    const resolveGroup = (root) => {
      const contentTip = contentTipOf(root);
      const contentNode = nodes.get(contentTip) || nodes.get(root);
      const lc = contentNode ? contentNode.c : {};
      const opinions = { ...(lc.opinions || {}) };
      const voters = safeArr(lc.opinions_inhabitants).slice();
      const voterSet = new Set(voters);
      for (const op of (opinionsByRoot.get(root) || [])) {
        if (voterSet.has(op.author)) continue;
        voterSet.add(op.author); voters.push(op.author);
        opinions[op.category] = (opinions[op.category] || 0) + 1;
      }
      return { contentTip, contentNode, opinions, voters };
    };

    const tipByRoot = new Map();
    for (const r of vg.roots) tipByRoot.set(r, contentTipOf(r));

    return { tomb, nodes, rootOf, tipByRoot, resolveGroup };
  };

  const buildImage = (node, rootId, viewerId, agg) => {
    const c = node.c || {};
    const voters = agg ? agg.voters : safeArr(c.opinions_inhabitants);
    return {
      key: node.key,
      rootId,
      url: c.url,
      createdAt: c.createdAt || new Date(node.ts).toISOString(),
      updatedAt: c.updatedAt || null,
      tags: safeArr(c.tags),
      author: node.author,
      title: c.title || "",
      description: c.description || "",
      license: c.license || "",
      mapUrl: c.mapUrl || "",
      opinions: agg ? agg.opinions : (c.opinions || {}),
      opinions_inhabitants: voters,
      hasVoted: viewerId ? voters.includes(viewerId) : false,
      sizeBytes: node.sizeBytes || 0
    };
  };

  return {
    type: "image",

    async resolveCurrentId(id) {
      const ssbClient = await openSsb();
      const messages = await getAllMessages(ssbClient);
      const idx = buildIndex(messages);

      const tip = idx.tipByRoot.get(idx.rootOf(id)) || id;
      if (idx.tomb.has(tip)) throw new Error("Image not found");
      return tip;
    },

    async resolveRootId(id) {
      const ssbClient = await openSsb();
      const messages = await getAllMessages(ssbClient);
      const idx = buildIndex(messages);

      const root = idx.rootOf(id);
      if (idx.tomb.has(idx.tipByRoot.get(root) || id)) throw new Error("Image not found");
      return root;
    },

    async createImage(blobMarkdown, tagsRaw, title, description, mapUrl, license) {
      const ssbClient = await openSsb();
      const blobId = parseBlobId(blobMarkdown);
      const tags = normalizeTags(tagsRaw) || [];
      const now = new Date().toISOString();

      const content = {
        type: "image",
        url: blobId,
        createdAt: now,
        updatedAt: now,
        author: ssbClient.id,
        tags,
        title: title || "",
        description: description || "",
        mapUrl: mapUrl || "",
        opinions: {},
        opinions_inhabitants: [],
        ...(license ? { license } : {})
      };

      return new Promise((resolve, reject) => {
        ssbClient.publish(content, (err, res) => (err ? reject(err) : resolve(res)));
      });
    },

    async updateImageById(id, blobMarkdown, tagsRaw, title, description, mapUrl, license) {
      const ssbClient = await openSsb();
      const userId = ssbClient.id;
      const tipId = await this.resolveCurrentId(id);
      const oldMsg = await getMsg(ssbClient, tipId);

      if (!oldMsg || oldMsg.content?.type !== "image") throw new Error("Image not found");
      if (oldMsg.content.author !== userId) throw new Error("Not the author");
      const aggImg = await this.getImageById(id, userId);
      if (aggImg && Object.keys(aggImg.opinions || {}).some(k => (aggImg.opinions[k] || 0) > 0)) throw new Error("Cannot edit image after it has received opinions.");

      const tags = tagsRaw !== undefined ? normalizeTags(tagsRaw) || [] : safeArr(oldMsg.content.tags);
      const blobId = blobMarkdown ? parseBlobId(blobMarkdown) : null;
      const now = new Date().toISOString();

      const updated = {
        ...oldMsg.content,
        replaces: tipId,
        url: blobId || oldMsg.content.url,
        tags,
        title: title !== undefined ? title || "" : oldMsg.content.title || "",
        description: description !== undefined ? description || "" : oldMsg.content.description || "",
        mapUrl: mapUrl !== undefined ? mapUrl || "" : oldMsg.content.mapUrl || "",
        createdAt: oldMsg.content.createdAt,
        updatedAt: now,
        ...(license !== undefined ? { license } : {})
      };

      const tombstone = { type: "tombstone", target: tipId, deletedAt: now, author: userId };
      await new Promise((res, rej) => ssbClient.publish(tombstone, (e) => (e ? rej(e) : res())));

      return new Promise((resolve, reject) => {
        ssbClient.publish(updated, (err, result) => (err ? reject(err) : resolve(result)));
      });
    },

    async deleteImageById(id) {
      const ssbClient = await openSsb();
      const userId = ssbClient.id;
      const tipId = await this.resolveCurrentId(id);
      const msg = await getMsg(ssbClient, tipId);

      if (!msg || msg.content?.type !== "image") throw new Error("Image not found");
      if (msg.content.author !== userId) throw new Error("Not the author");

      const tombstone = { type: "tombstone", target: tipId, deletedAt: new Date().toISOString(), author: userId };

      return new Promise((resolve, reject) => {
        ssbClient.publish(tombstone, (err2, res) => (err2 ? reject(err2) : resolve(res)));
      });
    },

    async listAll(filterOrOpts = "all", maybeOpts = {}) {
      const ssbClient = await openSsb();

      const opts = typeof filterOrOpts === "object" ? filterOrOpts : maybeOpts || {};
      const filter = (typeof filterOrOpts === "string" ? filterOrOpts : opts.filter || "all") || "all";
      const q = String(opts.q || "").trim().toLowerCase();
      const sort = String(opts.sort || "recent").trim();
      const viewerId = opts.viewerId || ssbClient.id;

      const messages = await getAllMessages(ssbClient);
      const idx = buildIndex(messages);

      const items = [];
      for (const [rootId, tipId] of idx.tipByRoot.entries()) {
        if (idx.tomb.has(tipId)) continue;
        const node = idx.nodes.get(tipId);
        if (!node) continue;
        items.push(buildImage(node, rootId, viewerId, idx.resolveGroup(rootId)));
      }

      let list = dedupeBy(items, x => x.url ? [norm(x.author), norm(x.url)].join('|') : null);
      const now = Date.now();

      if (filter === "mine") list = list.filter((im) => String(im.author) === String(viewerId));
      else if (filter === "recent") list = list.filter((im) => new Date(im.createdAt).getTime() >= now - 86400000);
      else if (filter === "top") {
        list = list
          .slice()
          .sort((a, b) => voteSum(b.opinions) - voteSum(a.opinions) || new Date(b.createdAt) - new Date(a.createdAt));
      }

      if (q) {
        list = list.filter((im) => {
          const t = String(im.title || "").toLowerCase();
          const d = String(im.description || "").toLowerCase();
          const tags = safeArr(im.tags).join(" ").toLowerCase();
          const a = String(im.author || "").toLowerCase();
          return t.includes(q) || d.includes(q) || tags.includes(q) || a.includes(q);
        });
      }

      if (sort === "top") {
        list = list
          .slice()
          .sort((a, b) => voteSum(b.opinions) - voteSum(a.opinions) || new Date(b.createdAt) - new Date(a.createdAt));
      } else if (sort === "oldest") {
        list = list.slice().sort((a, b) => new Date(a.createdAt) - new Date(b.createdAt));
      } else {
        list = list.slice().sort((a, b) => new Date(b.createdAt) - new Date(a.createdAt));
      }

      return list;
    },

    async getImageById(id, viewerId = null) {
      const ssbClient = await openSsb();
      const viewer = viewerId || ssbClient.id;

      const messages = await getAllMessages(ssbClient);
      const idx = memoIndex('images', messages, buildIndex);
      const rootId = idx.rootOf(id);
      const agg = idx.resolveGroup(rootId);
      if (!idx.tipByRoot.has(rootId) || !agg.contentNode || idx.tomb.has(agg.contentTip)) throw new Error("Image not found");

      return buildImage(agg.contentNode, rootId, viewer, agg);
    },

    async createOpinion(id, category) {
      if (!categories.includes(category)) throw new Error("Invalid voting category");

      const ssbClient = await openSsb();
      const userId = ssbClient.id;

      const img = await this.getImageById(id, userId);
      if (!img) throw new Error("Image not found");
      if (safeArr(img.opinions_inhabitants).includes(userId)) throw new Error("Already voted");

      const content = { type: "imageOpinion", target: img.rootId, category, createdAt: new Date().toISOString() };
      return new Promise((resolve, reject) => {
        ssbClient.publish(content, (err, result) => (err ? reject(err) : resolve(result)));
      });
    }
  };
};