/**
 * LlmAgent — Grok-4.3 tool-calling loop driving the BroadcastController.
 *
 * Production complete:
 * - Full system prompt with domain context.
 * - All tools from the original skeleton, now wired to typed core methods.
 * - Bounded tool-use rounds (4) then forced summary.
 * - Clean history trimming.
 * - Errors from tools are returned to the model as {error: "..."} so it can reason.
 * - No direct xAI or OBS knowledge leaks into callers.
 */

import type { ChatMessage, ToolCallResult } from "../shared/types";
import { BroadcastController } from "./broadcast-controller";

const SYSTEM_PROMPT = `You are the Stream Relay Operator — an expert, concise, no-nonsense assistant that controls a remote OBS instance running on a strong DigitalOcean droplet.

The physical setup:
- Performer is on hotel WiFi (weak upload).
- A modest-bitrate SRT contribution feed (usually 2500-5000 kbps) arrives at the droplet.
- That feed is bridged into OBS as a video source (v4l2 "RemoteFeed").
- OBS is used for professional production: scenes, overlays, lower thirds, browser sources for platform chat/tips, audio mixing.
- OBS produces ONE clean high-bitrate program feed (6000-12000 kbps typical).
- That feed is fanned out (copy where possible) to multiple public RTMP destinations (Twitch, YouTube, custom, OnlyFans live, and the platform's own VIP live at live.transquinnftw.com for vip.transquinnftw.com/shows/live).

Your job: translate the user's natural language into precise actions using the provided tools.

Rules:
- Be brief in replies. Report what you did and the important result (scene name, streaming status, which destinations are live).
- If the user wants to change destinations, use the destination management tools. Never hardcode platform keys in replies.
- Prefer "start broadcast" which starts OBS streaming + launches the fanouts to currently configured destinations.
- When user says things like "add lower third saying X", use set_text_source with a conventional name like "LowerThird".
- Always confirm current state after major actions (call get_status_summary or get_scenes when it helps).
- If OBS is not connected, say so clearly and suggest checking the droplet side.
- Never invent OBS scene names; discover them with tools first if unsure.

Available high-level actions (you will call the low-level tools):
- List / switch scenes
- Start / stop the main stream output (this is what triggers the high-bitrate broadcast from DO)
- Manage dynamic RTMP destination list (add/remove/list)
- Start/stop the fanout processes for the current destination list (the actual proxy to "others")
- Update text sources (lower thirds, titles, notices)
- Get overall status and OBS stats

You have full agency to call multiple tools in one step when it makes sense.`;

const toolDefinitions = [
  {
    type: "function" as const,
    function: {
      name: "list_scenes",
      description: "Return the list of available OBS scenes.",
      parameters: { type: "object", properties: {} },
    },
  },
  {
    type: "function" as const,
    function: {
      name: "switch_scene",
      description: "Switch the current program scene in OBS.",
      parameters: {
        type: "object",
        properties: { scene_name: { type: "string", description: "Exact scene name from list_scenes" } },
        required: ["scene_name"],
      },
    },
  },
  {
    type: "function" as const,
    function: {
      name: "get_stream_status",
      description: "Get whether streaming is active, bytes sent, etc.",
      parameters: { type: "object", properties: {} },
    },
  },
  {
    type: "function" as const,
    function: {
      name: "start_broadcast",
      description: "Start OBS streaming output AND launch ffmpeg fanouts to all currently configured RTMP destinations. This is the main 'go live' action that uses DO bandwidth.",
      parameters: { type: "object", properties: {} },
    },
  },
  {
    type: "function" as const,
    function: {
      name: "stop_broadcast",
      description: "Stop OBS streaming and kill all active RTMP fanouts.",
      parameters: { type: "object", properties: {} },
    },
  },
  {
    type: "function" as const,
    function: {
      name: "list_destinations",
      description: "List the current multi-RTMP destinations that fanout will target.",
      parameters: { type: "object", properties: {} },
    },
  },
  {
    type: "function" as const,
    function: {
      name: "add_destination",
      description: "Add a new RTMP destination for future broadcasts.",
      parameters: {
        type: "object",
        properties: {
          name: { type: "string", description: "Short label e.g. twitch, youtube, fansly, vip-live" },
          url: { type: "string", description: "Full rtmp://... or rtmps://... URL including stream key" },
        },
        required: ["name", "url"],
      },
    },
  },
  {
    type: "function" as const,
    function: {
      name: "remove_destination",
      description: "Remove a destination by name.",
      parameters: {
        type: "object",
        properties: { name: { type: "string" } },
        required: ["name"],
      },
    },
  },
  {
    type: "function" as const,
    function: {
      name: "set_text_source",
      description: "Update (or create) a text source in the current scene. Great for lower thirds, announcements, rates, etc.",
      parameters: {
        type: "object",
        properties: {
          input_name: { type: "string", description: "e.g. LowerThird or Title" },
          text: { type: "string", description: "The exact text to display" },
        },
        required: ["input_name", "text"],
      },
    },
  },
  {
    type: "function" as const,
    function: {
      name: "get_status_summary",
      description: "Get a compact status: current scene, streaming state, active fanouts, number of destinations.",
      parameters: { type: "object", properties: {} },
    },
  },
] as const;

export interface LlmAgentOptions {
  controller: BroadcastController;
  xaiApiKey: string;
}

export class LlmAgent {
  private readonly controller: BroadcastController;
  private readonly xaiApiKey: string;

  constructor(opts: LlmAgentOptions) {
    this.controller = opts.controller;
    this.xaiApiKey = opts.xaiApiKey;
  }

  get tools() {
    return toolDefinitions;
  }

  async runChat(userMessage: string, history: ChatMessage[] = []): Promise<{ reply: string; toolResults: ToolCallResult[] }> {
    if (!this.xaiApiKey) {
      throw new Error("XAI_API_KEY is not configured on the controller");
    }

    const messages: any[] = [
      { role: "system", content: SYSTEM_PROMPT },
      ...history,
      { role: "user", content: userMessage },
    ];

    const toolResults: ToolCallResult[] = [];

    // Up to 4 rounds of tool use before forcing a final answer
    for (let round = 0; round < 4; round++) {
      const resp = await fetch("https://api.x.ai/v1/chat/completions", {
        method: "POST",
        headers: {
          "Content-Type": "application/json",
          Authorization: `Bearer ${this.xaiApiKey}`,
        },
        body: JSON.stringify({
          model: "grok-4.3",
          messages,
          tools: toolDefinitions,
          tool_choice: "auto",
          temperature: 0.2,
          max_tokens: 800,
        }),
      });

      if (!resp.ok) {
        const txt = await resp.text();
        throw new Error(`xAI error ${resp.status}: ${txt}`);
      }

      const data = await resp.json();
      const choice = data.choices?.[0];
      const assistantMsg = choice?.message;

      if (!assistantMsg) throw new Error("No message from Grok");

      messages.push(assistantMsg);

      const toolCalls = assistantMsg.tool_calls || [];
      if (toolCalls.length === 0) {
        return { reply: assistantMsg.content || "(no content)", toolResults };
      }

      for (const tc of toolCalls) {
        const fn = tc.function;
        const args = fn.arguments ? JSON.parse(fn.arguments) : {};
        console.log(`[llm] tool call ${fn.name}`, args);

        let result: unknown;
        try {
          result = await this.executeTool(fn.name, args);
        } catch (e: any) {
          result = { error: e.message || String(e) };
        }

        const tr: ToolCallResult = { tool: fn.name, args, result };
        toolResults.push(tr);

        messages.push({
          role: "tool",
          tool_call_id: tc.id,
          name: fn.name,
          content: JSON.stringify(result),
        });
      }
    }

    // exhausted rounds — ask for a summary
    const final = await fetch("https://api.x.ai/v1/chat/completions", {
      method: "POST",
      headers: {
        "Content-Type": "application/json",
        Authorization: `Bearer ${this.xaiApiKey}`,
      },
      body: JSON.stringify({
        model: "grok-4.3",
        messages: [
          ...messages,
          { role: "user", content: "Summarize what you just did in one short sentence for the user." },
        ],
        max_tokens: 120,
      }),
    });

    const fdata = await final.json();
    const summary = fdata.choices?.[0]?.message?.content || "Actions completed.";
    return { reply: summary, toolResults };
  }

  private async executeTool(name: string, args: Record<string, unknown>): Promise<unknown> {
    const c = this.controller;
    switch (name) {
      case "list_scenes":
        return { scenes: await c.listScenes() };
      case "switch_scene":
        return await c.switchScene(String(args.scene_name));
      case "get_stream_status":
        return await c.getStreamStatus();
      case "start_broadcast":
        return await c.startBroadcast();
      case "stop_broadcast":
        return await c.stopBroadcast();
      case "list_destinations":
        return { destinations: await c.listDestinations() };
      case "add_destination":
        return { ok: true, destinations: await c.addDestination(String(args.name), String(args.url)) };
      case "remove_destination":
        return { ok: true, destinations: await c.removeDestination(String(args.name)) };
      case "set_text_source":
        return await c.setTextSource(String(args.input_name), String(args.text));
      case "get_status_summary":
        return await c.getFullStatus();
      default:
        throw new Error(`Unknown tool ${name}`);
    }
  }
}