{-# LANGUAGE OverloadedStrings #-}

module MetricsSpec (spec) where

import Data.HashMap.Strict (HashMap)
import qualified Data.HashMap.Strict as HM
import Data.Int (Int64)
import Data.Text (Text)
import HomeAssistant.Runtime.Metrics
  ( DsType (..)
  , DsSpec (..)
  , dsTypeOf
  , sanitizeName
  , buildSchema
  , buildCreateArgs
  , buildUpdateArgs
  )
import qualified System.Metrics as M (Value (..))
import Test.Hspec

spec :: Spec
spec = do
  describe "dsTypeOf" $ do
    it "maps Counter to Derive" $
      dsTypeOf (M.Counter 1000) `shouldBe` Just Derive

    it "maps Gauge to Gauge" $
      dsTypeOf (M.Gauge 500) `shouldBe` Just Gauge

    it "maps Label to Nothing" $
      dsTypeOf (M.Label "hello") `shouldBe` Nothing

  describe "sanitizeName" $ do
    it "replaces dots with underscores" $
      sanitizeName ("rts.gc.bytes_allocated" :: Text) `shouldBe` "rts_gc_bytes_allocated"

  describe "buildSchema" $ do
    it "builds sorted DsSpecs from counters and gauges, skipping labels" $
      let sample :: HashMap Text M.Value
          sample = HM.fromList
            [ ("rts.gc.bytes_allocated", M.Counter 1000)
            , ("rts.gc.max_bytes_used", M.Gauge 500)
            , ("rts.gc.label_thing", M.Label "irrelevant")
            ]
      in buildSchema sample `shouldBe`
           [ DsSpec "rts.gc.bytes_allocated" "rts_gc_bytes_allocated" Derive
           , DsSpec "rts.gc.max_bytes_used" "rts_gc_max_bytes_used" Gauge
           ]

  describe "buildCreateArgs" $ do
    it "builds create argv with mixed DERIVE and GAUGE DSes and RRAs" $
      buildCreateArgs "test.rrd" 10
        [ ("ds1", Derive)
        , ("ds2", Gauge)
        ]
        `shouldBe`
          [ "create"
          , "test.rrd"
          , "--step"
          , "10"
          , "DS:ds1:DERIVE:20:0:U"
          , "DS:ds2:GAUGE:20:0:U"
          , "RRA:AVERAGE:0.5:1:6000"
          , "RRA:MAX:0.5:1:6000"
          , "RRA:AVERAGE:0.5:360:1680"
          , "RRA:MAX:0.5:360:1680"
          ]

  describe "buildUpdateArgs" $ do
    it "builds update argv with numeric values" $
      buildUpdateArgs "test.rrd" ["ds1", "ds2"] [Just 100, Just 200]
        `shouldBe`
          [ "update"
          , "test.rrd"
          , "--template"
          , "ds1:ds2"
          , "N:100:200"
          ]

    it "renders Nothing as U (unknown)" $
      buildUpdateArgs "test.rrd" ["ds1", "ds2"] [Just 100, Nothing]
        `shouldBe`
          [ "update"
          , "test.rrd"
          , "--template"
          , "ds1:ds2"
          , "N:100:U"
          ]

    it "renders all-Nothing as all-U" $
      buildUpdateArgs "test.rrd" ["ds1"] [Nothing]
        `shouldBe`
          [ "update"
          , "test.rrd"
          , "--template"
          , "ds1"
          , "N:U"
          ]