package subscription

import (
	"errors"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"github.com/thrasher-corp/gocryptotrader/common"
	"github.com/thrasher-corp/gocryptotrader/currency"
	"github.com/thrasher-corp/gocryptotrader/exchanges/asset"
	"github.com/thrasher-corp/gocryptotrader/exchanges/kline"
)

// TestExpandTemplates exercises ExpandTemplates
func TestExpandTemplates(t *testing.T) {
	t.Parallel()

	e := newMockEx()
	e.tpl = "subscriptions.tmpl"

	// Functionality tests
	l := List{
		{Channel: "single-channel"},
		{Channel: "expand-assets", Asset: asset.All, Interval: kline.FifteenMin},
		{Channel: "expand-pairs", Asset: asset.All, Levels: 1},
		{Channel: "expand-pairs", Asset: asset.Spot, Levels: 2},
		{Channel: "single-channel", QualifiedChannel: "just one sub already processed"},
		{Channel: "update-asset-pairs", Asset: asset.All},
		{Channel: "expand-pairs", Asset: asset.Spot, Pairs: e.pairs[asset.Spot][0:2], Levels: 3},
		{Channel: "batching", Asset: asset.Spot},
		{Channel: "single-channel", Authenticated: true},
	}

	_, err := l.ExpandTemplates(&mockExWithSubValidator{mockEx: e, GenerateBadSubscription: true})
	require.ErrorIs(t, err, errValidateSubscriptionsTestError)
	_, err = l.ExpandTemplates(&mockExWithSubValidator{mockEx: e})
	require.NoError(t, err)
	_, err = l.ExpandTemplates(&mockExWithSubValidator{mockEx: e, FailGetSubscriptions: true})
	require.ErrorIs(t, err, ErrNotFound)

	got, err := l.ExpandTemplates(e)
	require.NoError(t, err, "ExpandTemplates must not error")
	exp := List{
		{Channel: "single-channel", QualifiedChannel: "single-channel"},
		{Channel: "expand-assets", QualifiedChannel: "spot-expand-assets@15m", Asset: asset.Spot, Pairs: e.pairs[asset.Spot], Interval: kline.FifteenMin},
		{Channel: "expand-assets", QualifiedChannel: "future-expand-assets@15m", Asset: asset.Futures, Pairs: e.pairs[asset.Futures], Interval: kline.FifteenMin},
		{Channel: "single-channel", QualifiedChannel: "just one sub already processed"},
		{Channel: "update-asset-pairs", QualifiedChannel: "spot-btcusdt-update-asset-pairs", Asset: asset.Spot, Pairs: currency.Pairs{btcusdtPair}},
		{Channel: "expand-pairs", QualifiedChannel: "spot-USDTBTC-expand-pairs@3", Asset: asset.Spot, Pairs: e.pairs[asset.Spot][1:2], Levels: 3},
		{Channel: "expand-pairs", QualifiedChannel: "spot-USDCETH-expand-pairs@3", Asset: asset.Spot, Pairs: e.pairs[asset.Spot][:1], Levels: 3},
	}
	for a, pairs := range e.pairs {
		if a == asset.Index { // Not IsAssetWebsocketEnabled
			continue
		}
		for _, p := range common.SortStrings(pairs) {
			pStr := p.Swap().String()
			if a == asset.Spot {
				exp = append(exp, List{
					{Channel: "expand-pairs", QualifiedChannel: "spot-" + pStr + "-expand-pairs@1", Asset: a, Pairs: currency.Pairs{p}, Levels: 1},
					&Subscription{Channel: "expand-pairs", QualifiedChannel: "spot-" + pStr + "-expand-pairs@2", Asset: a, Pairs: currency.Pairs{p}, Levels: 2},
				}...)
			} else {
				exp = append(exp,
					&Subscription{Channel: "expand-pairs", QualifiedChannel: "future-" + pStr + "-expand-pairs@1", Asset: a, Pairs: currency.Pairs{p}, Levels: 1},
				)
			}
		}
	}
	for _, b := range common.Batch(common.SortStrings(e.pairs[asset.Spot]), 3) {
		exp = append(exp, &Subscription{Channel: "batching", QualifiedChannel: "spot-" + b.Join() + "-batching", Asset: asset.Spot, Pairs: b})
	}

	if !equalLists(t, exp, got) {
		t.FailNow() // If the first list isn't equal testing it again will duplicate test failures
	}

	e.auth = true
	got, err = l.ExpandTemplates(e)
	require.NoError(t, err, "ExpandTemplates must not error")
	exp = append(exp, &Subscription{Channel: "single-channel", QualifiedChannel: "single-channel-authed"})
	equalLists(t, exp, got)

	// Test with just one asset to ensure asset.All works, and disabled assets don't error
	e.assets = e.assets[:1]
	l = List{
		{Channel: "expand-assets", Asset: asset.All, Interval: kline.OneHour},
		{Channel: "expand-pairs", Asset: asset.All, Levels: 4},
		{Channel: "single-channel", Asset: asset.Futures},
	}
	got, err = l.ExpandTemplates(e)
	require.NoError(t, err, "ExpandTemplates must not error")
	exp = List{
		{Channel: "expand-assets", QualifiedChannel: "spot-expand-assets@1h", Asset: asset.Spot, Pairs: e.pairs[asset.Spot], Interval: kline.OneHour},
	}
	for _, p := range e.pairs[asset.Spot] {
		exp = append(exp, List{
			{Channel: "expand-pairs", QualifiedChannel: "spot-" + p.Swap().String() + "-expand-pairs@4", Asset: asset.Spot, Pairs: currency.Pairs{p}, Levels: 4},
		}...)
	}
	equalLists(t, exp, got)

	// Users can specify pairs which aren't available, even across diverse assets
	// Use-case: Coinbase user sub for futures BTC-USD would return all BTC pairs and all USD pairs, even though BTC-USD might not be enabled or available
	p := currency.Pairs{currency.NewPairWithDelimiter("BEAR", "PEAR", "🐻")}
	got, err = List{{Channel: "expand-pairs", Asset: asset.All, Pairs: p}}.ExpandTemplates(e)
	require.NoError(t, err, "Must not error with fictional pairs")
	exp = List{{Channel: "expand-pairs", QualifiedChannel: "spot-PEARBEAR-expand-pairs@0", Asset: asset.Spot, Pairs: p}}
	equalLists(t, exp, got)

	// Error cases
	_, err = List{{Channel: "nil"}}.ExpandTemplates(e)
	assert.ErrorIs(t, err, errInvalidTemplate, "Should get correct error on nil template")

	e.tpl = "errors.tmpl"

	_, err = List{{Channel: "error1"}}.ExpandTemplates(e)
	assert.ErrorContains(t, err, "wrong number of args for String", "Should error correctly with execution error")

	_, err = List{{Channel: "empty-content", Asset: asset.Spot}}.ExpandTemplates(e)
	assert.ErrorIs(t, err, errNoTemplateContent, "Should error correctly when no content generated")
	assert.ErrorContains(t, err, "empty-content", "Should error correctly when no content generated")

	_, err = List{{Channel: "error2", Asset: asset.All}}.ExpandTemplates(e)
	assert.ErrorIs(t, err, errAssetRecords, "Should error correctly when invalid number of asset entries")

	_, err = List{{Channel: "error3", Asset: asset.Spot}}.ExpandTemplates(e)
	assert.ErrorIs(t, err, errPairRecords, "Should error correctly when invalid number of pair entries")

	_, err = List{{Channel: "error4", Asset: asset.Spot}}.ExpandTemplates(e)
	assert.ErrorIs(t, err, errTooManyBatchSizePerAsset, "Should error correctly when too many BatchSize directives")

	_, err = List{{Channel: "error5", Asset: asset.Spot}}.ExpandTemplates(e)
	assert.ErrorIs(t, err, common.ErrTypeAssertFailure, "Should error correctly when batch size isn't an int")

	e.tpl = "parse-error.tmpl"
	e.tpl = "parse-error.tmpl"
	_, err = l.ExpandTemplates(e)
	assert.ErrorContains(t, err, "function \"explode\" not defined", "Should error correctly on unparsable template")

	e.errFormat = errors.New("the planet Krypton is gone")
	_, err = l.ExpandTemplates(e)
	assert.ErrorIs(t, err, e.errFormat, "Should error correctly on GetPairFormat")

	e.errPairs = errors.New("bad parenting from Jor-El")
	_, err = l.ExpandTemplates(e)
	assert.ErrorIs(t, err, e.errPairs, "Should error correctly on GetEnabledPairs")

	l = List{{Channel: "single-channel", QualifiedChannel: "already happy"}}
	got, err = l.ExpandTemplates(e)
	require.NoError(t, err)
	require.Len(t, got, 1, "Must get back the one sub")
	assert.Equal(t, "already happy", l[0].QualifiedChannel, "Should get back the one sub")
	assert.NotSame(t, &got, &l, "Should get back a different actual list")

	_, err = List{{Channel: "nil"}}.ExpandTemplates(e)
	assert.ErrorIs(t, err, errInvalidTemplate, "Should get correct error on nil template")
}