package uiserver

import (
	"encoding/json"
	"fmt"
	"net/url"

	"github.com/hashicorp/consul/agent/config"
)

// uiTemplateDataFromConfig returns the set of variables that should be injected
// into the UI's Env based on the given runtime UI config.
func uiTemplateDataFromConfig(cfg *config.RuntimeConfig) (map[string]interface{}, error) {

	uiCfg := map[string]interface{}{
		"metrics_provider": cfg.UIConfig.MetricsProvider,
		// We explicitly MUST NOT pass the metrics_proxy object since it might
		// contain add_headers with secrets that the UI shouldn't know e.g. API
		// tokens for the backend. The provider should either require the proxy to
		// be configured and then use that or hit the backend directly from the
		// browser.
		"metrics_proxy_enabled":   cfg.UIConfig.MetricsProxy.BaseURL != "",
		"dashboard_url_templates": cfg.UIConfig.DashboardURLTemplates,
	}

	// Only set this if there is some actual JSON or we'll cause a JSON
	// marshalling error later during serving which ends up being silent.
	if cfg.UIConfig.MetricsProviderOptionsJSON != "" {
		uiCfg["metrics_provider_options"] = json.RawMessage(cfg.UIConfig.MetricsProviderOptionsJSON)
	}

	d := map[string]interface{}{
		"ContentPath": cfg.UIConfig.ContentPath,
		"ACLsEnabled": cfg.ACLsEnabled,
	}

	err := uiTemplateDataFromConfigEnterprise(cfg, d, uiCfg)
	if err != nil {
		return nil, err
	}

	// Render uiCfg down to JSON ready to inject into the template
	bs, err := json.Marshal(uiCfg)
	if err != nil {
		return nil, fmt.Errorf("failed marshalling UI Env JSON: %s", err)
	}
	// Need to also URLEncode it as it is passed through a META tag value. Path
	// variant is correct to avoid converting spaces to "+". Note we don't just
	// use html/template because it strips comments and uses a different encoding
	// for this param than Ember which is OK but just one more weird thing to
	// account for in the source...
	d["UIConfigJSON"] = url.PathEscape(string(bs))

	// Also inject additional provider scripts if needed, otherwise strip the
	// comment.
	if len(cfg.UIConfig.MetricsProviderFiles) > 0 {
		d["ExtraScripts"] = []string{
			cfg.UIConfig.ContentPath + compiledProviderJSPath,
		}
	}

	return d, err
}