package simulation

import (
	"fmt"
	"math/rand"
	"testing"

	abci "github.com/tendermint/tendermint/abci/types"

	"github.com/cosmos/cosmos-sdk/baseapp"
	sdk "github.com/cosmos/cosmos-sdk/types"
)

// assertAll asserts the all invariants against application state
func assertAllInvariants(t *testing.T, app *baseapp.BaseApp, invs sdk.Invariants,
	event string, logWriter LogWriter) {

	ctx := app.NewContext(false, abci.Header{Height: app.LastBlockHeight() + 1})

	for i := 0; i < len(invs); i++ {
		if err := invs[i](ctx); err != nil {
			fmt.Printf("Invariants broken after %s\n%s\n", event, err.Error())
			logWriter.PrintLogs()
			t.Fatal()
		}
	}
}

func getTestingMode(tb testing.TB) (testingMode bool, t *testing.T, b *testing.B) {
	testingMode = false
	if _t, ok := tb.(*testing.T); ok {
		t = _t
		testingMode = true
	} else {
		b = tb.(*testing.B)
	}
	return testingMode, t, b
}

// getBlockSize returns a block size as determined from the transition matrix.
// It targets making average block size the provided parameter. The three
// states it moves between are:
//  - "over stuffed" blocks with average size of 2 * avgblocksize,
//  - normal sized blocks, hitting avgBlocksize on average,
//  - and empty blocks, with no txs / only txs scheduled from the past.
func getBlockSize(r *rand.Rand, params Params,
	lastBlockSizeState, avgBlockSize int) (state, blocksize int) {

	// TODO: Make default blocksize transition matrix actually make the average
	// blocksize equal to avgBlockSize.
	state = params.BlockSizeTransitionMatrix.NextState(r, lastBlockSizeState)
	switch state {
	case 0:
		blocksize = r.Intn(avgBlockSize * 4)
	case 1:
		blocksize = r.Intn(avgBlockSize * 2)
	default:
		blocksize = 0
	}
	return state, blocksize
}

// PeriodicInvariant returns an Invariant function closure that asserts a given
// invariant if the mock application's last block modulo the given period is
// congruent to the given offset.
//
// NOTE this function is intended to be used manually used while running
// computationally heavy simulations.
// TODO reference this function in the codebase probably through use of a switch
func PeriodicInvariant(invariant sdk.Invariant, period int, offset int) sdk.Invariant {
	return func(ctx sdk.Context) error {
		if int(ctx.BlockHeight())%period == offset {
			return invariant(ctx)
		}
		return nil
	}
}

// PeriodicInvariants  returns an array of wrapped Invariants. Where each
// invariant function is only executed periodically defined by period and offset.
func PeriodicInvariants(invariants []sdk.Invariant, period int, offset int) []sdk.Invariant {
	var outInvariants []sdk.Invariant
	for _, invariant := range invariants {
		outInvariant := func(ctx sdk.Context) error {
			if int(ctx.BlockHeight())%period == offset {
				return invariant(ctx)
			}
			return nil
		}
		outInvariants = append(outInvariants, outInvariant)
	}
	return outInvariants
}