package main

import (
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"net/url"
)

// Fetch data from NASA Exoplanet API
func fetchExoplanetData(query string) ([]map[string]interface{}, error) {
	baseURL := "https://exoplanetarchive.ipac.caltech.edu/TAP/sync"

	params := url.Values{}
	params.Set("query", query)
	params.Set("format", "json")

	fullURL := baseURL + "?" + params.Encode()
	resp, err := http.Get(fullURL)
	if err != nil {
		return nil, fmt.Errorf("fetch error: %v", err)
	}
	defer resp.Body.Close()

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, fmt.Errorf("read error: %v", err)
	}

	var results []map[string]interface{}
	if err := json.Unmarshal(body, &results); err != nil {
		return nil, fmt.Errorf("unmarshal error: %v", err)
	}

	return results, nil
}

// Handler: /planets
func planetsHandler(w http.ResponseWriter, r *http.Request) {
	year := r.URL.Query().Get("year")
	query := "SELECT pl_name, disc_year FROM pscomppars"
	if year != "" {
		query += fmt.Sprintf(" WHERE disc_year = %s", year)
	}

	results, err := fetchExoplanetData(query)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	// Add inside each handler, before writing the response:
	w.Header().Set("Access-Control-Allow-Origin", "*")

	writeJSON(w, results)
}

// Handler: /planets/large-radius
func largeRadiusHandler(w http.ResponseWriter, r *http.Request) {
	query := "SELECT pl_name, pl_radj FROM pscomppars WHERE pl_radj > 5"

	results, err := fetchExoplanetData(query)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	// Add inside each handler, before writing the response:
	w.Header().Set("Access-Control-Allow-Origin", "*")

	writeJSON(w, results)
}

// Helper to write JSON response
func writeJSON(w http.ResponseWriter, data interface{}) {
	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(data)
}

// Main
func main() {
	http.HandleFunc("/planets", planetsHandler)
	http.HandleFunc("/planets/large-radius", largeRadiusHandler)

	fmt.Println("Server running at http://localhost:8080")
	log.Fatal(http.ListenAndServe(":8080", nil))
}