package wallet

import (
	"testing"
	"time"
)

// TestLocateBirthdayBlock ensures we can properly map a block in the chain to a
//timestamp.
func TestLocateBirthdayBlock(t *testing.T) {
	t.Parallel()

	// We'll use test chains of 30 blocks with a duration between two
	// consecutive blocks being slightly greater than the largest margin
	// allowed by locateBirthdayBlock. Doing so lets us test the method more
	// effectively as there is only one block within the chain that can map
	// to a timestamp (this does not apply to the first and last blocks,
	// which can map to many timestamps beyond either end of chain).
	const (
		numBlocks     = 30
		blockInterval = birthdayBlockDelta + 1
	)

	genesisTimestamp := chainParams.GenesisBlock.Header.Timestamp

	testCases := []struct {
		name           string
		birthday       time.Time
		birthdayHeight int32
	}{
		{
			name:           "left-right-left-left",
			birthday:       genesisTimestamp.Add(8 * blockInterval),
			birthdayHeight: 8,
		},
		{
			name:           "right-right-right-left",
			birthday:       genesisTimestamp.Add(27 * blockInterval),
			birthdayHeight: 27,
		},
		{
			name:           "before start height",
			birthday:       genesisTimestamp.Add(-blockInterval),
			birthdayHeight: 0,
		},
		{
			name:           "start height",
			birthday:       genesisTimestamp,
			birthdayHeight: 0,
		},
		{
			name:           "end height",
			birthday:       genesisTimestamp.Add(numBlocks * blockInterval),
			birthdayHeight: numBlocks - 1,
		},
		{
			name:           "after end height",
			birthday:       genesisTimestamp.Add(2 * numBlocks * blockInterval),
			birthdayHeight: numBlocks - 1,
		},
	}

	for _, testCase := range testCases {
		success := t.Run(testCase.name, func(t *testing.T) {
			chainConn := createMockChainConn(
				chainParams.GenesisBlock, numBlocks, blockInterval,
			)
			birthdayBlock, err := locateBirthdayBlock(
				chainConn, testCase.birthday,
			)
			if err != nil {
				t.Fatalf("unable to locate birthday block: %v",
					err)
			}
			if birthdayBlock.Height != testCase.birthdayHeight {
				t.Fatalf("expected birthday block with height "+
					"%d, got %d", testCase.birthdayHeight,
					birthdayBlock.Height)
			}
		})
		if !success {
			break
		}
	}
}