package api

import (
	"crypto/rand"
	"encoding/hex"
	"errors"
	"log/slog"
	"net/http"

	"github.com/go-chi/chi/v5"

	"github.com/alexei/tinyforge/internal/store"
)

// generateWebhookSecret returns a 256-bit hex-encoded random token. Mirrors
// the helper in internal/store; kept here to avoid an import cycle and so the
// rotation handlers don't pretend to use uuid for what is really a secret.
func generateWebhookSecret() string {
	b := make([]byte, 32)
	if _, err := rand.Read(b); err != nil {
		panic("crypto/rand failed: " + err.Error())
	}
	return hex.EncodeToString(b)
}

// webhookURLResponse is the common payload returned by every webhook endpoint.
// Clients never see raw secrets except at issue/rotate time via these fields;
// the URL shape is "/api/webhook/..." so callers can prepend their own origin.
type webhookURLResponse struct {
	WebhookURL    string `json:"webhook_url"`
	WebhookSecret string `json:"webhook_secret"`
}

// getProjectWebhook handles GET /api/projects/{id}/webhook.
// Returns the project's webhook URL + secret, generating one lazily if the
// project predates the per-project webhook migration.
func (s *Server) getProjectWebhook(w http.ResponseWriter, r *http.Request) {
	id := chi.URLParam(r, "id")

	secret, err := s.store.EnsureProjectWebhookSecret(id)
	if err != nil {
		if errors.Is(err, store.ErrNotFound) {
			respondNotFound(w, "project")
			return
		}
		slog.Error("get project webhook: ensure secret", "project", id, "error", err)
		respondError(w, http.StatusInternalServerError, "failed to get webhook secret")
		return
	}

	respondJSON(w, http.StatusOK, webhookURLResponse{
		WebhookURL:    "/api/webhook/" + secret,
		WebhookSecret: secret,
	})
}

// regenerateProjectWebhook handles POST /api/projects/{id}/webhook/regenerate.
// Rotates the project's webhook secret, invalidating the old URL.
func (s *Server) regenerateProjectWebhook(w http.ResponseWriter, r *http.Request) {
	id := chi.URLParam(r, "id")

	// Verify project exists before rotating.
	if _, err := s.store.GetProjectByID(id); err != nil {
		if errors.Is(err, store.ErrNotFound) {
			respondNotFound(w, "project")
			return
		}
		slog.Error("regenerate project webhook: lookup", "project", id, "error", err)
		respondError(w, http.StatusInternalServerError, "failed to get project")
		return
	}

	secret := generateWebhookSecret()
	if err := s.store.SetProjectWebhookSecret(id, secret); err != nil {
		slog.Error("regenerate project webhook: set secret", "project", id, "error", err)
		respondError(w, http.StatusInternalServerError, "failed to rotate webhook secret")
		return
	}

	slog.Info("project webhook secret rotated", "project", id)
	respondJSON(w, http.StatusOK, webhookURLResponse{
		WebhookURL:    "/api/webhook/" + secret,
		WebhookSecret: secret,
	})
}

// getStaticSiteWebhook handles GET /api/sites/{id}/webhook.
func (s *Server) getStaticSiteWebhook(w http.ResponseWriter, r *http.Request) {
	id := chi.URLParam(r, "id")

	secret, err := s.store.EnsureStaticSiteWebhookSecret(id)
	if err != nil {
		if errors.Is(err, store.ErrNotFound) {
			respondNotFound(w, "static site")
			return
		}
		slog.Error("get site webhook: ensure secret", "site", id, "error", err)
		respondError(w, http.StatusInternalServerError, "failed to get webhook secret")
		return
	}

	respondJSON(w, http.StatusOK, webhookURLResponse{
		WebhookURL:    "/api/webhook/sites/" + secret,
		WebhookSecret: secret,
	})
}

// regenerateStaticSiteWebhook handles POST /api/sites/{id}/webhook/regenerate.
func (s *Server) regenerateStaticSiteWebhook(w http.ResponseWriter, r *http.Request) {
	id := chi.URLParam(r, "id")

	if _, err := s.store.GetStaticSiteByID(id); err != nil {
		if errors.Is(err, store.ErrNotFound) {
			respondNotFound(w, "static site")
			return
		}
		slog.Error("regenerate site webhook: lookup", "site", id, "error", err)
		respondError(w, http.StatusInternalServerError, "failed to get static site")
		return
	}

	secret := generateWebhookSecret()
	if err := s.store.SetStaticSiteWebhookSecret(id, secret); err != nil {
		slog.Error("regenerate site webhook: set secret", "site", id, "error", err)
		respondError(w, http.StatusInternalServerError, "failed to rotate webhook secret")
		return
	}

	slog.Info("static site webhook secret rotated", "site", id)
	respondJSON(w, http.StatusOK, webhookURLResponse{
		WebhookURL:    "/api/webhook/sites/" + secret,
		WebhookSecret: secret,
	})
}