// Copyright 2019 Dolthub, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package commands

import (
	"context"
	"fmt"
	"os"
	"strings"
	"syscall"
	"testing"

	"github.com/stretchr/testify/require"

	"github.com/dolthub/dolt/go/libraries/doltcore/doltdb"
	"github.com/dolthub/dolt/go/libraries/doltcore/env"
	"github.com/dolthub/dolt/go/libraries/utils/osutil"
	"github.com/dolthub/dolt/go/store/types"
	"github.com/dolthub/dolt/go/store/util/outputpager"
)

func TestLog(t *testing.T) {
	ctx := context.Background()
	dEnv := createUninitializedEnv()
	err := dEnv.InitRepo(ctx, types.Format_DOLT, "Bill Billerson", "bigbillieb@fake.horse", env.DefaultInitBranch)
	defer dEnv.Close()

	if err != nil {
		t.Error("Failed to init repo")
	}

	cs, _ := doltdb.NewCommitSpec(env.DefaultInitBranch)
	opt, _ := dEnv.DoltDB(ctx).Resolve(context.Background(), cs, nil)
	commit, _ := opt.ToCommit()

	meta, _ := commit.GetCommitMeta(context.Background())
	require.Equal(t, "Bill Billerson", meta.Author.Name)
}

func TestLogSigterm(t *testing.T) {
	if osutil.IsWindows {
		t.Skip("Skipping test as function used is not supported on Windows")
	}

	ctx := context.Background()
	dEnv := createUninitializedEnv()
	err := dEnv.InitRepo(ctx, types.Format_DOLT, "Bill Billerson", "bigbillieb@fake.horse", env.DefaultInitBranch)
	defer dEnv.Close()

	if err != nil {
		t.Error("Failed to init repo")
	}

	cs, _ := doltdb.NewCommitSpec(env.DefaultInitBranch)
	optCmt, _ := dEnv.DoltDB(ctx).Resolve(context.Background(), cs, nil)
	commit, _ := optCmt.ToCommit()
	cMeta, _ := commit.GetCommitMeta(context.Background())
	cHash, _ := commit.HashOf()

	outputpager.SetTestingArg(true)
	defer outputpager.SetTestingArg(false)

	pager := outputpager.Start()
	defer pager.Stop()

	chStr := cHash.String()

	for i := 0; i < 5; i++ {
		pager.Writer.Write([]byte(fmt.Sprintf("\033[1;33mcommit %s \033[0m", chStr)))
		pager.Writer.Write([]byte(fmt.Sprintf("\nAuthor: %s <%s>", cMeta.Author.Name, cMeta.Author.Email)))

		timeStr := cMeta.FormatTS()
		pager.Writer.Write([]byte(fmt.Sprintf("\nDate:  %s", timeStr)))

		formattedDesc := "\n\n\t" + strings.Replace(cMeta.Description, "\n", "\n\t", -1) + "\n\n"
		pager.Writer.Write([]byte(formattedDesc))
	}

	process, err := os.FindProcess(syscall.Getpid())
	require.NoError(t, err)

	err = process.Signal(syscall.SIGTERM)
	require.NoError(t, err)
}

func TestDoltPagerEnvironmentVariable(t *testing.T) {
	// Test that DOLT_PAGER environment variable is respected
	originalPager := os.Getenv("DOLT_PAGER")
	defer func() {
		if originalPager == "" {
			os.Unsetenv("DOLT_PAGER")
		} else {
			os.Setenv("DOLT_PAGER", originalPager)
		}
	}()

	// Set DOLT_PAGER to head -n 2 for testing
	err := os.Setenv("DOLT_PAGER", "head -n 2")
	require.NoError(t, err)

	// Enable testing mode to bypass TTY check
	outputpager.SetTestingArg(true)
	defer outputpager.SetTestingArg(false)

	// Start the pager - it should use head -n 2 from DOLT_PAGER
	pager := outputpager.Start()
	defer pager.Stop()

	// Write multiple lines to test that head -n 2 truncates output
	testLines := []string{
		"line 1\n",
		"line 2\n",
		"line 3\n",
		"line 4\n",
		"line 5\n",
	}

	for _, line := range testLines {
		pager.Writer.Write([]byte(line))
	}

	// The test passes if the pager was created successfully with DOLT_PAGER
	// We can't easily test the actual truncation in a unit test since the pager
	// runs as a separate process, but we verify that the pager starts without error
	// when DOLT_PAGER is set to a valid command
	require.NotNil(t, pager)
	require.NotNil(t, pager.Writer)
}

func TestDoltPagerFallback(t *testing.T) {
	// Test that when DOLT_PAGER is empty, it falls back to less/more
	originalPager := os.Getenv("DOLT_PAGER")
	defer func() {
		if originalPager == "" {
			os.Unsetenv("DOLT_PAGER")
		} else {
			os.Setenv("DOLT_PAGER", originalPager)
		}
	}()

	// Unset DOLT_PAGER to test fallback
	os.Unsetenv("DOLT_PAGER")

	// Enable testing mode to bypass TTY check
	outputpager.SetTestingArg(true)
	defer outputpager.SetTestingArg(false)

	// Start the pager - it should fall back to less or more
	pager := outputpager.Start()
	defer pager.Stop()

	// Write some test content
	pager.Writer.Write([]byte("test line 1\n"))
	pager.Writer.Write([]byte("test line 2\n"))

	// The test passes if the pager was created successfully with fallback
	require.NotNil(t, pager)
	require.NotNil(t, pager.Writer)
}