const express = require("express");
const bodyParser = require("body-parser");

const app = express();

// Middleware to parse JSON
app.use(bodyParser.json());

// In-memory data store for demonstration
let attributesData = {
  attributes: [],
};

// CREATE - Add or update attributes
app.post("/attributes", (req, res) => {
  const { attributes } = req.body;

  if (!attributes || !Array.isArray(attributes)) {
    return res.status(400).json({ error: "Attributes must be an array" });
  }

  for (const attribute of attributes) {
    if (!attribute.key || !attribute.value) {
      return res.status(400).json({
        error: "Each attribute must have a 'key' and 'value'",
      });
    }

    // Check if the attribute already exists; if yes, update it
    const existingIndex = attributesData.attributes.findIndex(
      (item) => item.key === attribute.key
    );
    if (existingIndex !== -1) {
      attributesData.attributes[existingIndex].value = attribute.value;
    } else {
      // Add new attribute
      attributesData.attributes.push(attribute);
    }
  }

  res.status(201).json({
    message: "Attributes updated successfully",
    attributes: attributesData.attributes,
  });
});

// READ - Get all attributes
app.get("/attributes", (req, res) => {
  res.json({
    message: "Attributes retrieved successfully",
    attributes: attributesData.attributes,
  });
});

// READ - Get a specific attribute by key
app.get("/attributes/:key", (req, res) => {
  const { key } = req.params;

  const attribute = attributesData.attributes.find(
    (item) => item.key === key
  );

  if (!attribute) {
    return res.status(404).json({ error: `Attribute with key '${key}' not found` });
  }

  res.json({
    message: "Attribute retrieved successfully",
    attribute,
  });
});

// UPDATE - Update a specific attribute by key
app.put("/attributes/:key", (req, res) => {
  const { key } = req.params;
  const { value } = req.body;

  if (!value) {
    return res.status(400).json({ error: "Value is required to update the attribute" });
  }

  const attribute = attributesData.attributes.find(
    (item) => item.key === key
  );

  if (!attribute) {
    return res.status(404).json({ error: `Attribute with key '${key}' not found` });
  }

  // Update the value
  attribute.value = value;

  res.json({
    message: "Attribute updated successfully",
    attributes: attributesData.attributes,
  });
});

// DELETE - Remove a specific attribute by key
app.delete("/attributes/:key", (req, res) => {
  const { key } = req.params;

  const index = attributesData.attributes.findIndex(
    (item) => item.key === key
  );

  if (index === -1) {
    return res.status(404).json({ error: `Attribute with key '${key}' not found` });
  }

  // Remove the attribute
  attributesData.attributes.splice(index, 1);

  res.json({
    message: "Attribute deleted successfully",
    attributes: attributesData.attributes,
  });
});

// Export app for serverless deployment
module.exports = app;