package api

import (
	"encoding/json"
	"strconv"
	"strings"

	"github.com/torkelo/grafana-pro/pkg/bus"
	"github.com/torkelo/grafana-pro/pkg/middleware"
	m "github.com/torkelo/grafana-pro/pkg/models"
)

const configTemplate = `
	define(['settings'],
	function (Settings) {
		"use strict";
		return new Settings(%json%);
	});
	`

type configJsTmplModel struct {
	DataSources []*m.DataSource
}

// TODO: cleanup this ugly code
func renderConfig(data *configJsTmplModel) string {
	datasources := make(map[string]interface{})

	for i, ds := range data.DataSources {
		url := ds.Url

		if ds.Access == m.DS_ACCESS_PROXY {
			url = "/api/datasources/proxy/" + strconv.FormatInt(ds.Id, 10)
		}

		var dsMap = map[string]interface{}{
			"type": ds.Type,
			"url":  url,
		}

		if ds.Type == m.DS_INFLUXDB {
			if ds.Access == m.DS_ACCESS_DIRECT {
				dsMap["username"] = ds.User
				dsMap["password"] = ds.Password
				dsMap["url"] = url + "/db/" + ds.Database
			}
		}

		// temp hack, first is always default
		// TODO: implement default ds account setting
		if i == 0 {
			dsMap["default"] = true
		}

		datasources[ds.Name] = dsMap
	}

	// add grafana backend data source
	datasources["grafana"] = map[string]interface{}{
		"type":      "grafana",
		"url":       "",
		"grafanaDB": true,
	}

	jsonObj := map[string]interface{}{
		"datasources": datasources,
	}

	buff, _ := json.Marshal(jsonObj)

	return strings.Replace(configTemplate, "%json%", string(buff), 1)
}

func GetConfigJS(c *middleware.Context) {

	query := m.GetDataSourcesQuery{AccountId: c.GetAccountId()}
	err := bus.Dispatch(&query)

	if err != nil {
		c.Handle(500, "cold not load data sources", err)
		return
	}

	vm := configJsTmplModel{DataSources: query.Result}
	configStr := renderConfig(&vm)

	if err != nil {
		c.Handle(500, "Failed to generate config.js", err)
		return
	}

	c.Header().Set("Content-Type", "text/javascript; charset=UTF-8")
	c.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
	c.Header().Set("Pragma", "no-cache")
	c.Header().Set("Expires", "0")
	c.WriteHeader(200)

	c.Write([]byte(configStr))
}