// @deno-types="npm:@types/node"
import { XMLParser } from "npm:fast-xml-parser@4.3.5";
import { serve } from "https://deno.land/std@0.168.0/http/server.ts";
import { createClient } from "https://esm.sh/@supabase/supabase-js@2.38.4";

// Deno environment
declare const Deno: {
  env: {
    get(key: string): string | undefined;
  };
};

// OpenAI client
const OPENAI_API_KEY = Deno.env.get("OPENAI_API_KEY");
if (!OPENAI_API_KEY) {
  console.error("Missing OPENAI_API_KEY environment variable");
}

// URDF Joint type definition
interface URDFJoint {
  name: string;
  type: string;
  parent: string;
  child: string;
  axis?: {
    xyz: string;
  };
  origin?: {
    xyz: string;
    rpy: string;
  };
  limits?: {
    lower?: number;
    upper?: number;
    effort?: number;
    velocity?: number;
  };
}

// URDF Element interface to avoid 'any' type
interface URDFElement {
  name?: string;
  type?: string;
  parent?: { link?: string };
  child?: { link?: string };
  axis?: { xyz?: string };
  origin?: { xyz?: string; rpy?: string };
  limit?: {
    lower?: number;
    upper?: number;
    effort?: number;
    velocity?: number;
  };
}

// Animation request definition
interface AnimationRequest {
  robotName: string;
  urdfContent: string;
  description: string;
}

// Joint animation configuration
interface JointAnimationConfig {
  name: string;
  type: "sine" | "linear" | "constant";
  min: number;
  max: number;
  speed: number;
  offset: number;
  isDegrees?: boolean;
}

// Robot animation configuration
interface RobotAnimationConfig {
  joints: JointAnimationConfig[];
  speedMultiplier?: number;
}

// CORS headers for cross-origin requests
const corsHeaders = {
  "Access-Control-Allow-Origin": "*",
  "Access-Control-Allow-Headers":
    "authorization, x-client-info, apikey, content-type",
  "Access-Control-Allow-Methods": "POST, OPTIONS",
};

// Generate animation configuration using OpenAI
async function generateAnimationConfig(
  joints: URDFJoint[],
  description: string,
  robotName: string
): Promise<RobotAnimationConfig> {
  // Filter out fixed joints as they can't be animated
  const movableJoints = joints.filter(
    (joint) =>
      joint.type !== "fixed" &&
      joint.name &&
      (joint.type === "revolute" ||
        joint.type === "continuous" ||
        joint.type === "prismatic")
  );

  // Create a description of available joints for the AI
  const jointsDescription = movableJoints
    .map((joint) => {
      const limits = joint.limits
        ? `(limits: ${
            joint.limits.lower !== undefined ? joint.limits.lower : "none"
          } to ${
            joint.limits.upper !== undefined ? joint.limits.upper : "none"
          })`
        : "(no limits)";

      const axisInfo = joint.axis ? `axis: ${joint.axis.xyz}` : "no axis info";

      return `- ${joint.name}: type=${joint.type}, connects ${joint.parent} to ${joint.child}, ${axisInfo} ${limits}`;
    })
    .join("\n");

  // Create prompt for OpenAI
  const prompt = `
You are a robotics animation expert. I need you to create animation configurations for a robot named "${robotName}".

The user wants the following animation: "${description}"

Here are the available movable joints in the robot:
${jointsDescription}

Based on these joints and the user's description, create a valid animation configuration in JSON format.
The animation configuration should include:
1. A list of joint animations (only include joints that should move)
2. For each joint, specify:
   - name: The exact joint name from the list above (string)
   - type: Must be exactly one of "sine", "linear", or "constant" (string)
   - min: Minimum position value (number, respect joint limits if available)
   - max: Maximum position value (number, respect joint limits if available)
   - speed: Speed multiplier (number, 0.5-2.0 is a reasonable range, lower is slower)
   - offset: Phase offset in radians (number, 0 to 2π, useful for coordinating multiple joints)
   - isDegrees: Optional boolean, set to true if the min/max values are in degrees rather than radians

3. An optional global speedMultiplier (number, default: 1.0)

You must return ONLY valid JSON matching this EXACT schema:
{
  "joints": [
    {
      "name": string,
      "type": "sine" | "linear" | "constant",
      "min": number,
      "max": number,
      "speed": number,
      "offset": number,
      "isDegrees"?: boolean
    }
  ],
  "speedMultiplier"?: number
}

Important rules:
- Only include movable joints from the list provided
- Respect joint limits when available
- Create natural, coordinated movements that match the user's description
- If the description mentions specific joints, prioritize animating those
- For walking animations, coordinate leg joints with appropriate phase offsets
- For realistic motion, use sine waves with different offsets for natural movement
- DO NOT ADD ANY PROPERTIES that aren't in the schema above
- DO NOT INCLUDE customEasing or any other properties not in the schema
- Return ONLY valid JSON without comments or explanations
`;

  try {
    // Call OpenAI API
    const response = await fetch("https://api.openai.com/v1/chat/completions", {
      method: "POST",
      headers: {
        "Content-Type": "application/json",
        Authorization: `Bearer ${OPENAI_API_KEY}`,
      },
      body: JSON.stringify({
        model: "gpt-4o-mini",
        messages: [
          {
            role: "system",
            content:
              "You are a robotics animation expert that produces only valid JSON as output.",
          },
          {
            role: "user",
            content: prompt,
          },
        ],
        temperature: 0.7,
        max_tokens: 1000,
        response_format: { type: "json_object" },
      }),
    });

    if (!response.ok) {
      const errorData = await response.json();
      console.error("OpenAI API error:", errorData);
      throw new Error(`OpenAI API error: ${response.status}`);
    }

    const data = await response.json();
    const animationText = data.choices[0].message.content.trim();

    // Log the raw response for debugging
    console.log(
      "Raw OpenAI response:",
      animationText.substring(0, 200) +
        (animationText.length > 200 ? "..." : "")
    );

    // Parse JSON from the response
    let animationConfig: RobotAnimationConfig;
    try {
      // Since we're using response_format: { type: "json_object" }, this should always be valid JSON
      animationConfig = JSON.parse(animationText);
    } catch (e) {
      console.error("Failed to parse JSON response:", e);
      throw new Error(
        "Could not parse animation configuration from AI response"
      );
    }

    // Validate the animation config against our RobotAnimationConfig type
    if (!animationConfig.joints || !Array.isArray(animationConfig.joints)) {
      throw new Error(
        "Invalid animation configuration: missing or invalid joints array"
      );
    }

    // Default speedMultiplier if not provided
    if (animationConfig.speedMultiplier === undefined) {
      animationConfig.speedMultiplier = 1.0;
    } else if (typeof animationConfig.speedMultiplier !== "number") {
      throw new Error("Invalid speedMultiplier: must be a number");
    }

    // Validate all joints have required properties and correct types
    for (const joint of animationConfig.joints) {
      // Check required properties
      if (!joint.name || typeof joint.name !== "string") {
        throw new Error("Invalid joint: name is required and must be a string");
      }

      if (!joint.type || !["sine", "linear", "constant"].includes(joint.type)) {
        throw new Error(
          `Invalid joint type: ${joint.type} for joint ${joint.name}. Must be "sine", "linear", or "constant"`
        );
      }

      if (joint.min === undefined || typeof joint.min !== "number") {
        throw new Error(
          `Invalid min value for joint ${joint.name}: must be a number`
        );
      }

      if (joint.max === undefined || typeof joint.max !== "number") {
        throw new Error(
          `Invalid max value for joint ${joint.name}: must be a number`
        );
      }

      if (joint.speed === undefined || typeof joint.speed !== "number") {
        throw new Error(
          `Invalid speed value for joint ${joint.name}: must be a number`
        );
      }

      if (joint.offset === undefined || typeof joint.offset !== "number") {
        throw new Error(
          `Invalid offset value for joint ${joint.name}: must be a number`
        );
      }

      // Check optional properties
      if (
        joint.isDegrees !== undefined &&
        typeof joint.isDegrees !== "boolean"
      ) {
        throw new Error(
          `Invalid isDegrees value for joint ${joint.name}: must be a boolean`
        );
      }

      // Ensure no custom properties that aren't in our type
      const allowedProperties = [
        "name",
        "type",
        "min",
        "max",
        "speed",
        "offset",
        "isDegrees",
      ];
      const extraProperties = Object.keys(joint).filter(
        (key) => !allowedProperties.includes(key)
      );

      if (extraProperties.length > 0) {
        console.warn(
          `Warning: Joint ${
            joint.name
          } has extra properties not in JointAnimationConfig: ${extraProperties.join(
            ", "
          )}`
        );
        // Remove extra properties to ensure exact type match
        extraProperties.forEach((prop) => {
          delete joint[prop];
        });
      }
    }

    // Clean the final object to ensure it matches our type exactly
    const cleanedConfig: RobotAnimationConfig = {
      joints: animationConfig.joints.map((joint) => ({
        name: joint.name,
        type: joint.type,
        min: joint.min,
        max: joint.max,
        speed: joint.speed,
        offset: joint.offset,
        ...(joint.isDegrees !== undefined && { isDegrees: joint.isDegrees }),
      })),
      speedMultiplier: animationConfig.speedMultiplier,
    };

    // Log the cleaned config for debugging
    console.log(
      `Cleaned config: ${cleanedConfig.joints.length} joints, speedMultiplier: ${cleanedConfig.speedMultiplier}`
    );

    return cleanedConfig;
  } catch (error) {
    console.error("Error generating animation:", error);
    // Return a simple default animation if generation fails

    // Get at most 2 movable joints to animate
    const jointsToAnimate = movableJoints.slice(0, 2);

    if (jointsToAnimate.length === 0) {
      // If no movable joints found, create a message
      throw new Error(
        "Cannot generate animation: No movable joints found in the robot model"
      );
    }

    // Create a simple, safe animation for the available joints
    const fallbackConfig: RobotAnimationConfig = {
      joints: jointsToAnimate.map((joint) => ({
        name: joint.name,
        type: "sine" as const,
        min: joint.limits?.lower !== undefined ? joint.limits.lower : -0.5,
        max: joint.limits?.upper !== undefined ? joint.limits.upper : 0.5,
        speed: 1.0,
        offset: 0,
        isDegrees: false,
      })),
      speedMultiplier: 1.0,
    };

    console.log("Using fallback animation config:", fallbackConfig);
    return fallbackConfig;
  }
}

// Parse URDF XML and extract joint information
function parseUrdfForJoints(urdfContent: string): URDFJoint[] {
  const parser = new XMLParser({
    ignoreAttributes: false,
    attributeNamePrefix: "",
    parseAttributeValue: true,
  });

  try {
    const doc = parser.parse(urdfContent);

    if (!doc || !doc.robot) {
      throw new Error("No robot element found in URDF");
    }

    // Extract joints
    const joints: URDFJoint[] = [];
    const robotElement = doc.robot;

    if (robotElement.joint) {
      const jointElements = Array.isArray(robotElement.joint)
        ? robotElement.joint
        : [robotElement.joint];

      jointElements.forEach((joint: URDFElement) => {
        const jointData: URDFJoint = {
          name: joint.name || "",
          type: joint.type || "",
          parent: joint.parent?.link || "",
          child: joint.child?.link || "",
        };

        // Parse axis
        if (joint.axis) {
          jointData.axis = {
            xyz: joint.axis.xyz || "0 0 0",
          };
        }

        // Parse origin
        if (joint.origin) {
          jointData.origin = {
            xyz: joint.origin.xyz || "0 0 0",
            rpy: joint.origin.rpy || "0 0 0",
          };
        }

        // Parse limits
        if (joint.limit) {
          jointData.limits = {
            lower:
              joint.limit.lower !== undefined ? joint.limit.lower : undefined,
            upper:
              joint.limit.upper !== undefined ? joint.limit.upper : undefined,
            effort:
              joint.limit.effort !== undefined ? joint.limit.effort : undefined,
            velocity:
              joint.limit.velocity !== undefined
                ? joint.limit.velocity
                : undefined,
          };
        }

        joints.push(jointData);
      });
    }

    return joints;
  } catch (error) {
    console.error("Error parsing URDF XML:", error);
    throw new Error(
      `Could not parse URDF: ${
        error instanceof Error ? error.message : String(error)
      }`
    );
  }
}

// Main server function
serve(async (req) => {
  // Handle CORS preflight requests
  if (req.method === "OPTIONS") {
    return new Response("ok", { headers: corsHeaders });
  }

  try {
    if (req.method !== "POST") {
      throw new Error("Method not allowed");
    }

    // Parse request
    const requestData: AnimationRequest = await req.json();
    const { robotName, urdfContent, description } = requestData;

    if (!urdfContent) {
      throw new Error("No URDF content provided");
    }

    if (!description) {
      throw new Error("No animation description provided");
    }

    console.log(
      `Generating animation for ${robotName}: "${description.substring(
        0,
        100
      )}..."`
    );

    // Parse URDF to extract joint information
    const joints = parseUrdfForJoints(urdfContent);
    console.log(`Extracted ${joints.length} joints from URDF`);

    // Generate animation configuration
    const animationConfig = await generateAnimationConfig(
      joints,
      description,
      robotName
    );
    console.log(
      `Generated animation with ${animationConfig.joints.length} animated joints`
    );

    // Return the animation configuration
    return new Response(JSON.stringify(animationConfig), {
      headers: {
        ...corsHeaders,
        "Content-Type": "application/json",
      },
    });
  } catch (error) {
    console.error("Error processing animation request:", error);

    return new Response(
      JSON.stringify({
        error:
          error instanceof Error ? error.message : "Unknown error occurred",
      }),
      {
        status: 500,
        headers: {
          ...corsHeaders,
          "Content-Type": "application/json",
        },
      }
    );
  }
});