package edit

import (
	"bytes"
	"os"
	"path/filepath"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
	"github.com/warewulf/warewulf/internal/pkg/config"
	"github.com/warewulf/warewulf/internal/pkg/testenv"
	"github.com/warewulf/warewulf/internal/pkg/warewulfd"
)

func Test_OverlayEdit(t *testing.T) {
	tests := []struct {
		name         string
		overlayName  string
		fileName     string
		parents      bool
		editorScript string
		setup        func(t *testing.T, conf *config.WarewulfYaml, overlayName, fileName string) (mtime time.Time)
		wantErr      bool
		verify       func(t *testing.T, conf *config.WarewulfYaml, overlayName, fileName string, mtime time.Time)
	}{
		{
			name:        "edit existing file",
			overlayName: "test-overlay",
			fileName:    "test.txt",
			editorScript: `#!/bin/sh
sed -i 's/hello/world/' "$1"`,
			setup: func(t *testing.T, conf *config.WarewulfYaml, overlayName, fileName string) time.Time {
				overlayDir := filepath.Join(conf.Paths.SiteOverlaydir(), overlayName)
				assert.NoError(t, os.MkdirAll(overlayDir, 0755))
				assert.NoError(t, os.WriteFile(filepath.Join(overlayDir, fileName), []byte("hello"), 0644))
				return time.Time{}
			},
			wantErr: false,
			verify: func(t *testing.T, conf *config.WarewulfYaml, overlayName, fileName string, mtime time.Time) {
				overlayDir := filepath.Join(conf.Paths.SiteOverlaydir(), overlayName)
				content, err := os.ReadFile(filepath.Join(overlayDir, fileName))
				assert.NoError(t, err)
				assert.Equal(t, "world", string(content))
			},
		},
		{
			name:        "edit non-existing file",
			overlayName: "test-overlay",
			fileName:    "new-file.txt",
			editorScript: `#!/bin/sh
echo "new content" > "$1"`,
			setup: func(t *testing.T, conf *config.WarewulfYaml, overlayName, fileName string) time.Time {
				overlayDir := filepath.Join(conf.Paths.SiteOverlaydir(), overlayName)
				assert.NoError(t, os.MkdirAll(overlayDir, 0755))
				return time.Time{}
			},
			wantErr: false,
			verify: func(t *testing.T, conf *config.WarewulfYaml, overlayName, fileName string, mtime time.Time) {
				overlayDir := filepath.Join(conf.Paths.SiteOverlaydir(), overlayName)
				content, err := os.ReadFile(filepath.Join(overlayDir, fileName))
				assert.NoError(t, err)
				assert.Equal(t, "new content\n", string(content))
			},
		},
		{
			name:        "edit non-existing .ww file",
			overlayName: "test-overlay",
			fileName:    "template.ww",
			editorScript: `#!/bin/sh
sed -i 's/autogenerated by warewulf/edited by test/' "$1"`,
			setup: func(t *testing.T, conf *config.WarewulfYaml, overlayName, fileName string) time.Time {
				overlayDir := filepath.Join(conf.Paths.SiteOverlaydir(), overlayName)
				assert.NoError(t, os.MkdirAll(overlayDir, 0755))
				return time.Time{}
			},
			wantErr: false,
			verify: func(t *testing.T, conf *config.WarewulfYaml, overlayName, fileName string, mtime time.Time) {
				overlayDir := filepath.Join(conf.Paths.SiteOverlaydir(), overlayName)
				content, err := os.ReadFile(filepath.Join(overlayDir, fileName))
				assert.NoError(t, err)
				assert.Contains(t, string(content), "edited by test")
			},
		},
		{
			name:        "edit without changes",
			overlayName: "test-overlay",
			fileName:    "no-change.txt",
			editorScript: `#!/bin/sh
# Do nothing to the file
exit 0`,
			setup: func(t *testing.T, conf *config.WarewulfYaml, overlayName, fileName string) time.Time {
				overlayDir := filepath.Join(conf.Paths.SiteOverlaydir(), overlayName)
				assert.NoError(t, os.MkdirAll(overlayDir, 0755))
				filePath := filepath.Join(overlayDir, fileName)
				assert.NoError(t, os.WriteFile(filePath, []byte("original"), 0644))
				stat, err := os.Stat(filePath)
				assert.NoError(t, err)
				return stat.ModTime()
			},
			wantErr: false,
			verify: func(t *testing.T, conf *config.WarewulfYaml, overlayName, fileName string, mtime time.Time) {
				overlayDir := filepath.Join(conf.Paths.SiteOverlaydir(), overlayName)
				filePath := filepath.Join(overlayDir, fileName)
				stat, err := os.Stat(filePath)
				assert.NoError(t, err)
				assert.True(t, stat.ModTime().Equal(mtime), "ModTime should not have changed")
			},
		},
		{
			name:        "edit file in dist overlay (CoW)",
			overlayName: "dist-overlay",
			fileName:    "test.txt",
			editorScript: `#!/bin/sh
sed -i 's/dist/site/' "$1"`,
			setup: func(t *testing.T, conf *config.WarewulfYaml, overlayName, fileName string) time.Time {
				overlayDir := filepath.Join(conf.Paths.DistributionOverlaydir(), overlayName)
				assert.NoError(t, os.MkdirAll(overlayDir, 0755))
				assert.NoError(t, os.WriteFile(filepath.Join(overlayDir, fileName), []byte("dist content"), 0644))
				return time.Time{}
			},
			wantErr: false,
			verify: func(t *testing.T, conf *config.WarewulfYaml, overlayName, fileName string, mtime time.Time) {
				distOverlayFile := filepath.Join(conf.Paths.DistributionOverlaydir(), overlayName, fileName)
				content, err := os.ReadFile(distOverlayFile)
				assert.NoError(t, err)
				assert.Equal(t, "dist content", string(content))

				siteOverlayFile := filepath.Join(conf.Paths.SiteOverlaydir(), overlayName, fileName)
				content, err = os.ReadFile(siteOverlayFile)
				assert.NoError(t, err)
				assert.Equal(t, "site content", string(content))
			},
		},
		{
			name:        "edit in missing dir no parents",
			overlayName: "test-overlay",
			fileName:    "newdir/test.txt",
			editorScript: `#!/bin/sh
echo "content" > "$1"`,
			setup: func(t *testing.T, conf *config.WarewulfYaml, overlayName, fileName string) time.Time {
				overlayDir := filepath.Join(conf.Paths.SiteOverlaydir(), overlayName)
				assert.NoError(t, os.MkdirAll(overlayDir, 0755))
				return time.Time{}
			},
			wantErr: true,
			verify: func(t *testing.T, conf *config.WarewulfYaml, overlayName, fileName string, mtime time.Time) {
				overlayFile := filepath.Join(conf.Paths.SiteOverlaydir(), overlayName, fileName)
				_, err := os.Stat(overlayFile)
				assert.True(t, os.IsNotExist(err))
			},
		},
		{
			name:        "edit in missing dir with parents",
			overlayName: "test-overlay",
			fileName:    "newdir/test.txt",
			parents:     true,
			editorScript: `#!/bin/sh
echo "content" > "$1"`,
			setup: func(t *testing.T, conf *config.WarewulfYaml, overlayName, fileName string) time.Time {
				overlayDir := filepath.Join(conf.Paths.SiteOverlaydir(), overlayName)
				assert.NoError(t, os.MkdirAll(overlayDir, 0755))
				return time.Time{}
			},
			wantErr: false,
			verify: func(t *testing.T, conf *config.WarewulfYaml, overlayName, fileName string, mtime time.Time) {
				overlayFile := filepath.Join(conf.Paths.SiteOverlaydir(), overlayName, fileName)
				content, err := os.ReadFile(overlayFile)
				assert.NoError(t, err)
				assert.Equal(t, "content\n", string(content))
			},
		},
	}

	warewulfd.SetNoDaemon()
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			env := testenv.New(t)
			defer env.RemoveAll()
			conf := env.Configure()

			scriptPath := filepath.Join(t.TempDir(), "fake_editor.sh")
			err := os.WriteFile(scriptPath, []byte(tt.editorScript), 0755)
			assert.NoError(t, err)
			t.Setenv("EDITOR", scriptPath)

			var mtime time.Time
			if tt.setup != nil {
				mtime = tt.setup(t, conf, tt.overlayName, tt.fileName)
			}

			var args []string
			if tt.parents {
				args = []string{"--parents", tt.overlayName, tt.fileName}
			} else {
				args = []string{tt.overlayName, tt.fileName}
			}

			baseCmd := GetCommand()
			baseCmd.SetArgs(args)
			buf := new(bytes.Buffer)
			baseCmd.SetOut(buf)
			baseCmd.SetErr(buf)
			err = baseCmd.Execute()

			if tt.wantErr {
				assert.Error(t, err)
			} else {
				assert.NoError(t, err)
			}

			if tt.verify != nil {
				tt.verify(t, conf, tt.overlayName, tt.fileName, mtime)
			}
		})
	}
}