chore: implement runRevert in readme

Author: anirbanfaith

README.md

@@ -30,18 +30,19 @@ commitdog reads what you actually changed and writes the message for you. You pi
 
 ## install
 
+**Linux and macOS**
+
 ```sh
-curl -fsSL https://get.commitdog.dev | sh
+curl -fsSL https://aysdog.pages.dev/install-commitdog.sh | sh
 ```
 
-that's it. one command. works on Linux and macOS.
-
-<details>
-<summary>Windows</summary>
+**Windows** — open PowerShell as Administrator and run:
 
-Download `commitdog-windows-amd64.exe` from the [releases page](https://github.com/aysdog/commitdog/releases), rename it to `commitdog.exe` and add it to your PATH.
+```powershell
+irm https://aysdog.pages.dev/install-commitdog.ps1 | iex
+```
 
-</details>
+downloads the binary, adds it to PATH automatically. restart your terminal and `commitdog` just works.
 
 <details>
 <summary>build from source (needs Go 1.21+)</summary>
@@ -101,6 +102,36 @@ pick a number. press enter to push. that's the whole thing.
 
 ---
 
+## made a mistake? revert it
+
+```sh
+commitdog revert
+```
+
+```
+  recent commits:
+
+  1  63baabe  docs(dummy): update dummy       (2 minutes ago)
+  2  3b7486d  feat(auth): add refreshToken    (1 hour ago)
+  3  c90ace2  refactor: update 10 files       (6 hours ago)
+  4  57f7669  refactor(docs): update docs     (6 hours ago)
+  5  4403b0f  refactor: update 13 files       (6 hours ago)
+
+  [1-5] pick, [e] enter hash, [q] quit › 1
+
+  reverting 63baabe — docs(dummy): update dummy
+  ⚠  this creates a new revert commit. continue? [Y/n] ›
+
+  ✓ reverted 63baabe
+
+  push to origin/main? [Y/n] ›
+  ✓ pushed to origin/main
+```
+
+pick the bad commit. confirm. done. no git syntax needed.
+
+---
+
 ## starting a brand new project
 
 no more going to GitHub, creating a repo, copying the URL, setting the remote. commitdog does all of it:
@@ -143,6 +174,7 @@ commitdog init
 | command | what it does |
 |---------|-------------|
 | `commitdog` | suggest commit message for staged changes |
+| `commitdog revert` | pick from last 5 commits and revert |
 | `commitdog init` | create a GitHub repo and do the first push |
 | `commitdog setup` | configure email and GitHub token (do once) |
 | `commitdog --version` | print version |

main.go

@@ -5,14 +5,14 @@ import (
 	"os"
 )
 
-const version = "0.1.1"
+const version = "0.1.2"
 
 func main() {
 	if len(os.Args) > 1 {
 		switch os.Args[1] {
 		case "--version", "-v":
-			fmt.Printf("commitdog v%s\n", version)
-			fmt.Println("zero-bs commits · no AI · no bs")
+			fmt.Println("commitdog v" + version)
+			fmt.Println("zero-bs commits · no AI · no telemetry")
 			fmt.Println("aysdog.pages.dev")
 			os.Exit(0)
 		case "--help", "-h":
@@ -24,6 +24,9 @@ func main() {
 		case "init":
 			runInit()
 			os.Exit(0)
+		case "revert":
+			runRevert()
+			os.Exit(0)
 		default:
 			fmt.Fprintf(os.Stderr, "unknown command: %s\n", os.Args[1])
 			fmt.Fprintf(os.Stderr, "run 'commitdog --help' for usage.\n")
@@ -76,6 +79,7 @@ usage:
   commitdog          generate commit message from staged diff
   commitdog init     create a new GitHub repo and do the first push
   commitdog setup    configure email and GitHub token
+  commitdog revert   pick from last 5 commits and revert
   commitdog -v       show version
   commitdog -h       show this help
 
@@ -89,6 +93,9 @@ workflow:
     git add .
     commitdog        ← suggests message, commits, asks to push
 
+  oops:
+    commitdog revert ← pick a commit to revert, push
+
 no ai. no network (except init). no telemetry. just works.`)
 }
 

revert.go

@@ -0,0 +1,222 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+)
+
+type commitEntry struct {
+	hash    string
+	subject string
+	date    string
+}
+
+func runRevert() {
+	if err := verifyGitRepo(); err != nil {
+		fatal("not a git repository.")
+	}
+
+	commits, err := getRecentCommits(5)
+	if err != nil {
+		fatal("could not read git log: %v", err)
+	}
+	if len(commits) == 0 {
+		fatal("no commits found in this repository.")
+	}
+
+	fmt.Println()
+	fmt.Println("  recent commits:")
+	fmt.Println()
+
+	for i, c := range commits {
+		fmt.Printf("  %d  %s  %s  %s\n",
+			i+1,
+			colorDim(c.hash),
+			c.subject,
+			colorMuted("("+c.date+")"),
+		)
+	}
+
+	fmt.Println()
+	fmt.Printf("  [1-%d] pick, [e] enter hash, [q] quit › ", len(commits))
+
+	var chosen string
+
+	for {
+		input := readLine()
+
+		switch input {
+		case "q", "quit", "exit":
+			fmt.Println("  aborted.")
+			return
+		case "e", "edit":
+			chosen = askForHash()
+			if chosen == "" {
+				return
+			}
+			goto revert
+		}
+
+		for i, c := range commits {
+			if input == fmt.Sprintf("%d", i+1) {
+				chosen = c.hash
+				goto revert
+			}
+		}
+
+		fmt.Printf("  enter 1-%d, e, or q › ", len(commits))
+	}
+
+revert:
+	chosen = strings.TrimSpace(chosen)
+	chosen = strings.ToLower(chosen)
+	if !isSafeHash(chosen) {
+		fatal("invalid commit hash: %q", chosen)
+	}
+
+	subject := subjectForHash(chosen, commits)
+	fmt.Println()
+	if subject != "" {
+		fmt.Printf("  reverting %s — %s\n", chosen[:7], subject)
+	} else {
+		fmt.Printf("  reverting %s\n", chosen[:7])
+	}
+
+	fmt.Printf("  ⚠  this creates a new revert commit. continue? [Y/n] › ")
+	confirm := readLine()
+	if confirm == "n" || confirm == "no" {
+		fmt.Println("  aborted.")
+		return
+	}
+
+	if err := gitRevert(chosen); err != nil {
+		fatal("revert failed: %v\n\n  tip: if there are conflicts, resolve them manually and run 'git revert --continue'", err)
+	}
+
+	fmt.Printf("\n  ✓ reverted %s\n", chosen[:7])
+
+	askPush()
+}
+
+func getRecentCommits(n int) ([]commitEntry, error) {
+	// use a unique separator that won't appear in commit messages
+	sep := "|||"
+	format := "%h" + sep + "%s" + sep + "%cr"
+
+	cmd := exec.Command(
+		"git", "log",
+		fmt.Sprintf("-%d", n),
+		"--no-color",
+		"--pretty=format:"+format,
+	)
+	cmd.Env = append(os.Environ(), "GIT_PAGER=cat")
+
+	var stdout, stderr bytes.Buffer
+	cmd.Stdout = &stdout
+	cmd.Stderr = &stderr
+
+	if err := cmd.Run(); err != nil {
+		return nil, fmt.Errorf("%s", strings.TrimSpace(stderr.String()))
+	}
+
+	lines := strings.Split(strings.TrimSpace(stdout.String()), "\n")
+	var commits []commitEntry
+
+	for _, line := range lines {
+		line = strings.TrimSpace(line)
+		if line == "" {
+			continue
+		}
+		parts := strings.SplitN(line, sep, 3)
+		if len(parts) != 3 {
+			continue
+		}
+
+		hash := strings.TrimSpace(parts[0])
+		subject := strings.TrimSpace(parts[1])
+		date := strings.TrimSpace(parts[2])
+
+		if len(subject) > 60 {
+			subject = subject[:57] + "..."
+		}
+
+		if !isSafeHash(hash) {
+			continue
+		}
+
+		commits = append(commits, commitEntry{
+			hash:    hash,
+			subject: subject,
+			date:    date,
+		})
+	}
+
+	return commits, nil
+}
+
+func askForHash() string {
+	fmt.Println()
+	fmt.Printf("  enter commit hash (7-40 hex chars) › ")
+
+	for {
+		input := strings.TrimSpace(readLine())
+		input = strings.ToLower(input)
+
+		if input == "" || input == "q" {
+			fmt.Println("  aborted.")
+			return ""
+		}
+		if !isSafeHash(input) {
+			fmt.Printf("  invalid hash — only hex characters (0-9, a-f), 7-40 chars › ")
+			continue
+		}
+		return input
+	}
+}
+
+func gitRevert(hash string) error {
+	cmd := exec.Command("git", "revert", hash, "--no-edit")
+	cmd.Env = append(os.Environ(), "GIT_PAGER=cat")
+	var stderr bytes.Buffer
+	cmd.Stderr = &stderr
+	if err := cmd.Run(); err != nil {
+		msg := strings.TrimSpace(stderr.String())
+		if msg == "" {
+			return fmt.Errorf("git revert failed")
+		}
+		return fmt.Errorf("%s", msg)
+	}
+	return nil
+}
+
+func isSafeHash(s string) bool {
+	if len(s) < 7 || len(s) > 40 {
+		return false
+	}
+	for _, c := range s {
+		if !((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f')) {
+			return false
+		}
+	}
+	return true
+}
+
+func subjectForHash(hash string, commits []commitEntry) string {
+	for _, c := range commits {
+		if strings.HasPrefix(c.hash, hash) || strings.HasPrefix(hash, c.hash) {
+			return c.subject
+		}
+	}
+	return ""
+}
+
+func colorDim(s string) string {
+	return "\033[2m" + s + "\033[0m"
+}
+
+func colorMuted(s string) string {
+	return "\033[90m" + s + "\033[0m"
+}