package handlers

import (
	"net/http"
	"time"

	"github.com/go-chi/chi"
	"sneak.berlin/go/webhooker/internal/database"
	"sneak.berlin/go/webhooker/internal/reqtls"
)

// HandleSourceDetail shows details for a specific webhook.
func (h *Handlers) HandleSourceDetail() http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		userID, ok := h.getUserID(r)
		if !ok {
			http.Redirect(
				w, r, "/pages/login", http.StatusSeeOther,
			)

			return
		}

		sourceID := chi.URLParam(r, "sourceID")

		var webhook database.Webhook

		err := h.db.DB().Where(
			"id = ? AND user_id = ?", sourceID, userID,
		).First(&webhook).Error
		if err != nil {
			h.renderError(w, r, http.StatusNotFound)

			return
		}

		h.renderSourceDetail(w, r, webhook, targetFormInput{}, "")
	}
}

// renderSourceDetail loads and renders a source detail page. With a
// targetErr, it is the page shown again for a refused add target
// form: it answers 400, and the form opens on targetForm's type with
// its values and the message.
func (h *Handlers) renderSourceDetail(
	w http.ResponseWriter,
	r *http.Request,
	webhook database.Webhook,
	targetForm targetFormInput,
	targetErr string,
) {
	var entrypoints []database.Entrypoint

	h.db.DB().Where(
		"webhook_id = ?", webhook.ID,
	).Find(&entrypoints)

	var targets []database.Target

	h.db.DB().Where(
		"webhook_id = ?", webhook.ID,
	).Find(&targets)

	entrypointViews := NewEntrypointViews(entrypoints)

	var events []RecentEventView

	if h.dbMgr.DBExists(webhook.ID) {
		webhookDB, err := h.dbMgr.GetDB(webhook.ID)
		if err != nil {
			h.serverError(w, r, "failed to get webhook database", err)

			return
		}

		events, err = loadRecentEvents(
			webhookDB, webhook.ID, singleHTTPTargetID(targets),
		)
		if err != nil {
			h.serverError(w, r, "failed to load recent events", err)

			return
		}

		err = addEntrypointEvents(
			webhookDB, &webhook, entrypointViews, time.Now(),
		)
		if err != nil {
			h.serverError(w, r, "failed to count entrypoint events", err)

			return
		}
	}

	scheme := "http"
	if reqtls.IsTLS(r) {
		scheme = "https"
	}

	// The host is the client's Host header, unvalidated. It is
	// inert only because source_detail.html renders BaseURL as
	// text, inside a <code> element and in an entrypoint's delete
	// prompt; putting it in an href or any other URL context
	// needs it constrained first.
	baseURL := scheme + "://" + r.Host

	// The template calls Webhook methods, which take pointer
	// receivers; html/template cannot address a value stored in a map.
	data := map[string]any{
		tmplKeyWebhook: &webhook,
		// Targets are projected to a display-safe view: a
		// target's stored config blob holds a credential, and it
		// must never reach a template.
		"Entrypoints":     entrypointViews,
		"Targets":         h.targetRows(&webhook, targets),
		"Events":          events,
		"BaseURL":         baseURL,
		"Stats":           h.loadWebhookStats(webhook.ID, entrypoints, targets),
		tmplKeyTargetForm: targetForm,
		"TargetError":     targetErr,
		// The add target form's selects start on its expiry and
		// rotation through Alpine, so no choice is selected here.
		tmplKeyArchiveExpiryChoices:   archiveExpiryChoices(),
		tmplKeyArchiveRotationChoices: archiveRotationChoices(),
	}

	status := http.StatusOK
	if targetErr != "" {
		status = http.StatusBadRequest
	}

	h.renderTemplateStatus(w, r, "source_detail.html", data, status)
}