package main

import (
	"encoding/json"
	"flag"
	"os"
	"os/exec"
	"reflect"
	"strings"
	"testing"

	"src.opensuse.org/autogits/common"
)

func TestMain(m *testing.M) {
	if os.Getenv("BE_MAIN") == "1" {
		main()
		return
	}
	os.Exit(m.Run())
}

func TestRun(t *testing.T) {
	tests := []struct {
		name          string
		inData        string
		expectedOut   string
		params        []string
		expectedError string
		isDir         bool
	}{
		{
			name:        "add user to existing package",
			inData:      `{"pkg1": ["user1"]}`,
			params:      []string{"-package", "pkg1", "-add", "user2"},
			expectedOut: `{"pkg1": ["user1", "user2"]}`,
		},
		{
			name:        "add user to new package",
			inData:      `{"pkg1": ["user1"]}`,
			params:      []string{"-package", "pkg2", "-add", "user2"},
			expectedOut: `{"pkg1": ["user1"], "pkg2": ["user2"]}`,
		},
		{
			name:        "no-op with no users",
			inData:      `{"pkg1": ["user1"]}`,
			params:      []string{"-package", "pkg1", "-add"},
			expectedOut: `{"pkg1": ["user1"]}`,
		},
		{
			name:        "add existing user",
			inData:      `{"pkg1": ["user1", "user2"]}`,
			params:      []string{"-package", "pkg1", "-add", "user2"},
			expectedOut: `{"pkg1": ["user1", "user2"]}`,
		},
		{
			name:        "remove user from package",
			inData:      `{"pkg1": ["user1", "user2"]}`,
			params:      []string{"-package", "pkg1", "-rm", "user2"},
			expectedOut: `{"pkg1": ["user1"]}`,
		},
		{
			name:        "remove last user from package",
			inData:      `{"pkg1": ["user1"]}`,
			params:      []string{"-package", "pkg1", "-rm", "user1"},
			expectedOut: `{}`,
		},
		{
			name:        "remove non-existent user",
			inData:      `{"pkg1": ["user1"]}`,
			params:      []string{"-package", "pkg1", "-rm", "user2"},
			expectedOut: `{"pkg1": ["user1"]}`,
		},
		{
			name:        "lint only unsorted",
			inData:      `{"pkg1": ["user2", "user1"]}`,
			params:      []string{"-lint-only"},
			expectedOut: `{"pkg1": ["user1", "user2"]}`,
		},
		{
			name:        "lint only no changes",
			inData:      `{"pkg1": ["user1", "user2"]}`,
			params:      []string{"-lint-only"},
			expectedOut: `{"pkg1": ["user1", "user2"]}`,
		},
		{
			name:          "no file",
			params:        []string{"-add"},
			expectedError: "no such file or directory",
		},
		{
			name:          "invalid json",
			inData:        `{"pkg1": ["user1"`,
			params:        []string{"-add"},
			expectedError: "Failed to parse JSON",
		},
		{
			name:        "add",
			inData:      `{"pkg1": ["user1", "user2"]}`,
			params:      []string{"-package", "pkg1", "-add", "user3"},
			expectedOut: `{"pkg1": ["user1", "user2", "user3"]}`,
		},
		{
			name:        "lint specific file",
			inData:      `{"pkg1": ["user2", "user1"]}`,
			params:      []string{"-lint-only", "other.json"},
			expectedOut: `{"pkg1": ["user1", "user2"]}`,
		},
		{
			name:        "add user to package when it was not there before",
			inData:      `{}`,
			params:      []string{"-package", "newpkg", "-add", "user1"},
			expectedOut: `{"newpkg": ["user1"]}`,
		},
		{
			name:          "unreadable file (is a directory)",
			isDir:         true,
			params:        []string{"-rm"},
			expectedError: "is a directory",
		},
		{
			name:          "remove user from non-existent package",
			inData:        `{"pkg1": ["user1"]}`,
			params:        []string{"-package", "pkg2", "-rm", "user2"},
			expectedError: "No package pkg2 and not adding one.",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			dir := t.TempDir()
			oldWd, _ := os.Getwd()
			_ = os.Chdir(dir)
			defer os.Chdir(oldWd)

			targetFile := common.MaintainershipFile
			if tt.name == "lint specific file" {
				targetFile = "other.json"
			}

			if tt.isDir {
				_ = os.Mkdir(targetFile, 0755)
			} else if tt.inData != "" {
				_ = os.WriteFile(targetFile, []byte(tt.inData), 0644)
			}

			flag.CommandLine = flag.NewFlagSet(os.Args[0], flag.ContinueOnError)

			os.Args = append([]string{"cmd"}, tt.params...)
			err := run()

			if tt.expectedError != "" {
				if err == nil {
					t.Fatalf("expected error containing %q, but got none", tt.expectedError)
				}
				if !strings.Contains(err.Error(), tt.expectedError) {
					t.Fatalf("expected error containing %q, got %q", tt.expectedError, err.Error())
				}
			} else if err != nil {
				t.Fatalf("unexpected error: %v", err)
			}

			if tt.expectedOut != "" {
				data, _ := os.ReadFile(targetFile)
				var got, expected map[string][]string
				_ = json.Unmarshal(data, &got)
				_ = json.Unmarshal([]byte(tt.expectedOut), &expected)

				if len(got) == 0 && len(expected) == 0 {
					return
				}

				if !reflect.DeepEqual(got, expected) {
					t.Fatalf("expected %v, got %v", expected, got)
				}
			}
		})
	}
}

func TestMainRecursive(t *testing.T) {
	tests := []struct {
		name        string
		inData      string
		expectedOut string
		params      []string
		expectExit  bool
	}{
		{
			name:        "test main() via recursive call",
			inData:      `{"pkg1": ["user1"]}`,
			params:      []string{"-package", "pkg1", "-add", "user2"},
			expectedOut: `{"pkg1": ["user1", "user2"]}`,
		},
		{
			name:       "test main() failure",
			params:     []string{"-package", "pkg1"},
			expectExit: true,
		},
	}

	exe, _ := os.Executable()

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			dir := t.TempDir()
			oldWd, _ := os.Getwd()
			_ = os.Chdir(dir)
			defer os.Chdir(oldWd)

			if tt.inData != "" {
				_ = os.WriteFile(common.MaintainershipFile, []byte(tt.inData), 0644)
			}

			cmd := exec.Command(exe, append([]string{"-test.run=None"}, tt.params...)...)
			cmd.Env = append(os.Environ(), "BE_MAIN=1")
			out, runErr := cmd.CombinedOutput()

			if tt.expectExit {
				if runErr == nil {
					t.Fatalf("expected exit with error, but it succeeded")
				}
				return
			}

			if runErr != nil {
				t.Fatalf("unexpected error: %v: %s", runErr, string(out))
			}

			if tt.expectedOut != "" {
				data, _ := os.ReadFile(common.MaintainershipFile)
				var got, expected map[string][]string
				_ = json.Unmarshal(data, &got)
				_ = json.Unmarshal([]byte(tt.expectedOut), &expected)

				if !reflect.DeepEqual(got, expected) {
					t.Fatalf("expected %v, got %v", expected, got)
				}
			}
		})
	}
}