const fs = require("fs");
const path = require("path");
const { compareVersions } = require("./tool_loader");

class ToolManager {
  constructor(options = {}) {
    this.repoClient = options.repoClient;
    this.installer = options.installer;
    this.loader = options.loader;
  }

  async list({ force = false } = {}) {
    const remoteResult = await this.repoClient.discover({ force });
    const localRows = this.installer.scanLocal();
    const remoteMap = new Map(remoteResult.tools.map((metadata) => [metadata.tool_id, metadata]));
    const localMap = new Map(localRows.map((entry) => [entry.tool_id, entry]));
    const ids = [...new Set([...remoteMap.keys(), ...localMap.keys()])].sort();
    return {
      repository: remoteResult.repository,
      branch: remoteResult.branch,
      checked_at: remoteResult.checked_at,
      cached: remoteResult.cached,
      stale: remoteResult.stale,
      error: remoteResult.error || null,
      tools: ids.map((toolId) => {
        const remote = remoteMap.get(toolId) || null;
        const local = localMap.get(toolId) || null;
        const metadata = local?.metadata || remote;
        const installed = Boolean(local);
        const remoteMissing = installed && !remote;
        const enabled = installed && this.loader.isEnabled(toolId);
        const runtime = this.loader.status(toolId);
        const updateAvailable = Boolean(
          installed && remote && local.valid && !remote.remote_invalid &&
          compareVersions(remote.version, local.metadata.version) > 0
        );
        const dependencies = local?.valid ? this.loader.inspectDependencies(local.metadata, local.dir) : { blocking: [], optional: [] };
        return {
          ...metadata,
          installed,
          enabled,
          local_version: installed ? local.metadata.version : null,
          remote_version: remote?.version || null,
          update_available: updateAvailable,
          update_enabled: installed && Boolean(remote) && !remote?.remote_invalid,
          remote_missing: remoteMissing,
          local_only: remoteMissing,
          local_valid: local?.valid !== false,
          local_error: local?.error || null,
          remote_invalid: remote?.remote_invalid === true,
          remote_error: remote?.remote_error || null,
          runtime_state: runtime.state,
          runtime_message: runtime.message,
          dependency_status: dependencies,
          primary_type: metadata?.tool_type || "general",
          primary_scope: displayScope(metadata?.scope)
        };
      })
    };
  }

  async enable(toolId) {
    let installed = this.installer.local(toolId);
    if (!installed) {
      const remote = await this.repoClient.discover();
      if (!remote.tools.some((entry) => entry.tool_id === toolId && !entry.remote_invalid)) {
        throw new Error("Remote AI tool plugin is unavailable.");
      }
      await this.installer.install(toolId);
      installed = this.installer.local(toolId);
    }
    return this.loader.enable(toolId);
  }

  async disable(toolId) {
    return this.loader.disable(toolId);
  }

  async update(toolId) {
    const local = this.installer.local(toolId);
    if (!local) throw new Error("Install the AI tool plugin before updating it.");
    const remote = await this.repoClient.discover({ force: true });
    if (!remote.tools.some((entry) => entry.tool_id === toolId && !entry.remote_invalid)) {
      throw new Error("This installed tool is missing from the configured repository.");
    }
    const wasEnabled = this.loader.isEnabled(toolId);
    if (wasEnabled) await this.loader.disable(toolId, { persist: false });
    try {
      const result = await this.installer.update(toolId);
      if (wasEnabled) await this.loader.enable(toolId, { persist: false });
      this.loader.setEnabled(toolId, wasEnabled);
      return result;
    } catch (error) {
      if (wasEnabled && this.installer.local(toolId)) {
        try { await this.loader.enable(toolId, { persist: false }); } catch {}
        this.loader.setEnabled(toolId, true);
      }
      throw error;
    }
  }

  async delete(toolId) {
    await this.loader.disable(toolId);
    const deleted = this.installer.delete(toolId);
    this.loader.setEnabled(toolId, false);
    return { deleted };
  }

  async readme(toolId) {
    const local = this.installer.local(toolId);
    if (local) {
      const file = path.join(local.dir, "readme.md");
      if (!fs.existsSync(file)) throw new Error("Installed tool readme.md is missing.");
      return { markdown: fs.readFileSync(file, "utf8"), source: "local" };
    }
    return { markdown: await this.repoClient.readReadme(toolId), source: "remote" };
  }

  async loadEnabled() {
    return this.loader.loadEnabled();
  }

  async stopAll() {
    return this.loader.stopAll();
  }

  resolveAsset(toolId, relative) {
    return this.loader.resolveAsset(toolId, relative);
  }
}

function displayScope(scope) {
  if (typeof scope === "string") return scope;
  if (Array.isArray(scope)) return scope.join(", ");
  if (scope && typeof scope === "object") return scope.label || scope.required_role || JSON.stringify(scope);
  return "unspecified";
}

module.exports = { ToolManager, displayScope };