import { Guild, ChannelType } from "discord.js";
import * as fs from "node:fs";
import * as path from "node:path";
import { DisclawDatabase } from "../db/database.js";
import { ResolvedCategories, moveToCategory } from "./categories.js";
import { childLogger } from "../runtime/logger.js";

const log = childLogger("lifecycle:reconcile");

export interface ReconcileResult {
  active: string[];
  inactive: string[];
  archived: string[];
  deletedWorkspaces: string[];
}

export async function reconcile(
  guild: Guild,
  db: DisclawDatabase,
  categories: ResolvedCategories,
  workspacesRoot: string,
  managementChannelId: string
): Promise<ReconcileResult> {
  const result: ReconcileResult = {
    active: [],
    inactive: [],
    archived: [],
    deletedWorkspaces: [],
  };

  // 1. Ensure the full channel cache is populated
  await guild.channels.fetch();

  // 2. Get all DB workspaces, excluding the management placeholder
  const allDbWorkspaces = db
    .getAllWorkspaces()
    .filter((w) => w.workspace_path !== "__management__");

  // 3. Scan workspace directories for directories containing agent.yaml
  const workspaceDirsWithYaml = new Set<string>();
  const workspaceDirChannelMap = new Map<string, string>(); // dirName -> channel_id

  if (fs.existsSync(workspacesRoot)) {
    for (const entry of fs.readdirSync(workspacesRoot)) {
      const dirPath = path.join(workspacesRoot, entry);
      try {
        const stat = fs.statSync(dirPath);
        if (!stat.isDirectory()) continue;
      } catch {
        continue;
      }
      const yamlPath = path.join(dirPath, "agent.yaml");
      if (fs.existsSync(yamlPath)) {
        workspaceDirsWithYaml.add(entry);
        // Try to read channel_id from agent.yaml
        try {
          const content = fs.readFileSync(yamlPath, "utf-8");
          // Simple extraction without full YAML parse to avoid import issues in tests
          const match = content.match(/channel_id:\s*["']?([^"'\s]+)["']?\s*$/m);
          if (match) {
            workspaceDirChannelMap.set(entry, match[1]);
          }
        } catch {
          // ignore unreadable yaml
        }
      }
    }
  }

  // 4. Collect category channel IDs to skip during archive scan
  const categoryChannelIds = new Set([
    categories.active.id,
    categories.inactive.id,
    categories.archive.id,
  ]);

  // 5. Track handled channel IDs so we don't double-process
  const handledChannelIds = new Set<string>();
  handledChannelIds.add(managementChannelId);
  categoryChannelIds.forEach((id) => handledChannelIds.add(id));

  // 6. Process each DB workspace entry
  for (const ws of allDbWorkspaces) {
    const channelExists = guild.channels.cache.has(ws.channel_id);
    const wsDir = Object.keys(
      Object.fromEntries(
        [...workspaceDirsWithYaml].map((d) => [d, path.join(workspacesRoot, d)])
      )
    ).find((d) => {
      const resolvedPath = path.join(workspacesRoot, d);
      return resolvedPath === ws.workspace_path || resolvedPath === path.resolve(ws.workspace_path);
    });
    const workspaceDirExists = ws.workspace_path !== "__management__" &&
      fs.existsSync(ws.workspace_path);

    if (channelExists && workspaceDirExists) {
      await moveToCategory(ws.channel_id, categories.active);
      result.active.push(ws.channel_id);
      log.info({ channelId: ws.channel_id, agentName: ws.agent_name }, "Reconcile: active");
    } else {
      if (channelExists) {
        await moveToCategory(ws.channel_id, categories.inactive);
        result.inactive.push(ws.channel_id);
        log.info({ channelId: ws.channel_id, agentName: ws.agent_name }, "Reconcile: inactive (workspace missing)");
      } else {
        result.inactive.push(ws.channel_id);
        log.info({ channelId: ws.channel_id, agentName: ws.agent_name }, "Reconcile: inactive (channel missing)");
      }
    }
    handledChannelIds.add(ws.channel_id);
    void wsDir; // suppress unused warning
  }

  // 7. Process workspace directories that have agent.yaml but no DB entry
  const dbChannelIds = new Set(allDbWorkspaces.map((w) => w.channel_id));

  for (const dirName of workspaceDirsWithYaml) {
    const channelId = workspaceDirChannelMap.get(dirName);
    if (!channelId) continue;

    if (dbChannelIds.has(channelId)) {
      // Already handled in step 6
      continue;
    }

    const dirPath = path.join(workspacesRoot, dirName);
    const channelExists = guild.channels.cache.has(channelId);

    if (channelExists) {
      await moveToCategory(channelId, categories.inactive);
      result.inactive.push(channelId);
      log.info({ channelId, dirName }, "Reconcile: inactive (workspace dir, no DB entry)");
    } else {
      // No DB entry, no channel → delete orphaned workspace directory
      try {
        fs.rmSync(dirPath, { recursive: true, force: true });
        result.deletedWorkspaces.push(dirName);
        log.info({ dirName }, "Reconcile: deleted orphaned workspace dir");
      } catch (err) {
        log.warn({ dirName, err }, "Reconcile: failed to delete orphaned workspace dir");
      }
    }

    if (channelId) handledChannelIds.add(channelId);
  }

  // 8. Archive any remaining text channels with no DB mapping
  for (const [id, ch] of guild.channels.cache) {
    if (handledChannelIds.has(id)) continue;
    if (ch.type !== ChannelType.GuildText) continue;

    await moveToCategory(id, categories.archive);
    result.archived.push(id);
    log.info({ channelId: id }, "Reconcile: archived (no DB entry)");
  }

  return result;
}