package main

import (
	"bufio"
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
	"path"
	"strings"
	"time"
)

func loadDotEnvIfExists(filename string) bool {
	f, err := os.Open(filename)
	if err != nil {
		return false
	}
	defer f.Close()

	scanner := bufio.NewScanner(f)
	for scanner.Scan() {
		line := strings.TrimSpace(scanner.Text())
		if line == "" || strings.HasPrefix(line, "#") {
			continue
		}
		k, v, ok := strings.Cut(line, "=")
		if !ok {
			continue
		}
		k = strings.TrimSpace(k)
		v = strings.TrimSpace(v)
		v = strings.Trim(v, "\"'")

		if k == "" {
			continue
		}
		if _, exists := os.LookupEnv(k); exists {
			continue
		}
		_ = os.Setenv(k, v)
	}

	return true
}

func envOr(key, def string) string {
	if v, ok := os.LookupEnv(key); ok {
		v = strings.TrimSpace(v)
		if v != "" {
			return v
		}
	}
	return def
}

func normalizeHookPath(p string) string {
	p = strings.TrimSpace(p)
	if p == "" {
		return "/hook"
	}
	p = "/" + strings.TrimLeft(p, "/")
	p = path.Clean(p)
	if p == "." {
		return "/hook"
	}
	return p
}

func main() {
	_ = loadDotEnvIfExists(".env") || loadDotEnvIfExists("../.env")

	port := envOr("PORT", "8080")
	hookPath := normalizeHookPath(envOr("HOOK_PATH", "/hook"))

	mux := http.NewServeMux()
	mux.HandleFunc(hookPath, func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodPost {
			w.Header().Set("Allow", http.MethodPost)
			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
			return
		}

		body, err := io.ReadAll(r.Body)
		if err != nil {
			http.Error(w, "failed to read body", http.StatusBadRequest)
			return
		}

		ts := time.Now().Format(time.RFC3339Nano)
		log.Printf("hook received ts=%s bytes=%d payload=%s", ts, len(body), string(body))

		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte("{\"ok\":true}"))
	})

	mux.HandleFunc("/health", func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte("{\"status\":\"up\"}"))
	})

	addr := ":" + port
	fmt.Printf("Listening on http://localhost%s\n", addr)
	fmt.Printf("Hook URL: http://localhost%s%s\n", addr, hookPath)

	srv := &http.Server{
		Addr:              addr,
		Handler:           mux,
		ReadHeaderTimeout: 5 * time.Second,
	}

	log.Fatal(srv.ListenAndServe())
}