#!/bin/bash
set -e

NC='\033[0m'

RED='\033[00;31m'
GREEN='\033[00;32m'
YELLOW='\033[00;33m'
BLUE='\033[00;34m'
PURPLE='\033[00;35m'
CYAN='\033[00;36m'
LIGHTGRAY='\033[00;37m'
MAGENTA='\033[00;35m'
LRED='\033[01;31m'
LGREEN='\033[01;32m'
LYELLOW='\033[01;33m'
LBLUE='\033[01;34m'
LPURPLE='\033[01;35m'
LCYAN='\033[01;36m'
WHITE='\033[01;37m'

GRAFANA_URL=http://admin:admin@localhost:3000


grafana_api() {
  local verb=$1
  local url=$2
  local params=$3
  local bodyfile=$4
  local response
  local cmd

  cmd="curl -L -s --fail -H \"Accept: application/json\" -H \"Content-Type: application/json\" -X ${verb} -k ${GRAFANA_URL}${url}"
  [[ -n "${params}" ]] && cmd="${cmd} -d \"${params}\""
  [[ -n "${bodyfile}" ]] && cmd="${cmd} --data @${bodyfile}"
  echo -e "Running ${cmd}"
  eval ${cmd} || return 1
  return 0
}

wait_for_api() {
  echo -e "${BLUE}Waiting for Grafana to be available...${NC}"
  while ! grafana_api GET /api/user/preferences
  do
    echo -e "${BLUE}Waiting still...${NC}"
    sleep 15
  done
}

replace_datasource() {
   local dashboard_file=$1
   local datasource_name=$2
   local old_datasource_name=$3
   cmd="sed -i.bak_remove \"s/${old_datasource_name}/${datasource_name}/g\" ${dashboard_file}"
   eval ${cmd} || return 1
   return 0
}

install_dashboards() {
  local dashboard

  for dashboard in /var/lib/grafana/ds/dashboards/*.json

  do
  if [[ $(grep "\"name\": \"DS_INFLUXDB\"," ${dashboard}) ]]; then
    echo -e "${PURPLE}Dashboard ${dashboard} seems to be for InfluxDB datasource${NC}"
    old_datasource_name="\\\${DS_INFLUXDB}"
    datasource_name="influxdb"
  fi 
  if [[ $(grep "\"name\": \"DS_PROMETHEUS\"," ${dashboard}) ]]; then
    echo -e "${PURPLE}Dashboard ${dashboard} seems to be for Prometheus datasource${NC}"
    old_datasource_name="\\\${DS_PROMETHEUS}"
    datasource_name="prometheus"
  fi 
    if [[ -f "${dashboard}" ]]; then
      echo -e "${LCYAN}Installing dashboard ${dashboard}${NC}"
      replace_datasource ${dashboard} ${datasource_name} ${old_datasource_name}
      cp ${dashboard} ${dashboard}.wrapped
      sed -i '1s/^/{"dashboard":\n/' ${dashboard}.wrapped
      echo "}" >> ${dashboard}.wrapped

      if grafana_api POST /api/dashboards/db "" "${dashboard}.wrapped"; then
        echo -e "\n** ${GREEN}installed ok **${NC}"
      else
        echo -e "\n** ${RED}installation of: ${PURPLE}\"${dashboard}\"${RED} failed **${NC}"
      fi
    fi
  done
}

configure_grafana() {
  wait_for_api
  install_dashboards
}

configure_grafana
rm -vf /var/lib/grafana/ds/dashboards/*.{wrapped,bak_remove}