cascade_cli/stack/
rebase.rs

1use crate::errors::{CascadeError, Result};
2use crate::git::{ConflictAnalyzer, GitRepository};
3use crate::stack::{Stack, StackManager};
4use chrono::Utc;
5use serde::{Deserialize, Serialize};
6use std::collections::HashMap;
7use tracing::{debug, info, warn};
8use uuid::Uuid;
9
10/// Conflict resolution result
11#[derive(Debug, Clone)]
12enum ConflictResolution {
13    /// Conflict was successfully resolved
14    Resolved,
15    /// Conflict is too complex for automatic resolution
16    TooComplex,
17}
18
19/// Represents a conflict region in a file
20#[derive(Debug, Clone)]
21#[allow(dead_code)]
22struct ConflictRegion {
23    /// Byte position where conflict starts
24    start: usize,
25    /// Byte position where conflict ends  
26    end: usize,
27    /// Line number where conflict starts
28    start_line: usize,
29    /// Line number where conflict ends
30    end_line: usize,
31    /// Content from "our" side (before separator)
32    our_content: String,
33    /// Content from "their" side (after separator)
34    their_content: String,
35}
36
37/// Strategy for rebasing stacks (force-push is the only valid approach for preserving PR history)
38#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
39pub enum RebaseStrategy {
40    /// Force-push rebased commits to original branches (preserves PR history)
41    /// This is the industry standard used by Graphite, Phabricator, spr, etc.
42    ForcePush,
43    /// Interactive rebase with conflict resolution
44    Interactive,
45}
46
47/// Options for rebase operations
48#[derive(Debug, Clone)]
49pub struct RebaseOptions {
50    /// The rebase strategy to use
51    pub strategy: RebaseStrategy,
52    /// Whether to run interactively (prompt for user input)
53    pub interactive: bool,
54    /// Target base branch to rebase onto
55    pub target_base: Option<String>,
56    /// Whether to preserve merge commits
57    pub preserve_merges: bool,
58    /// Whether to auto-resolve simple conflicts
59    pub auto_resolve: bool,
60    /// Maximum number of retries for conflict resolution
61    pub max_retries: usize,
62    /// Skip pulling latest changes (when already done by caller)
63    pub skip_pull: Option<bool>,
64    /// Original working branch to restore after rebase (if different from base)
65    /// This is critical to prevent updating the base branch when sync checks out to it
66    pub original_working_branch: Option<String>,
67}
68
69/// Result of a rebase operation
70#[derive(Debug)]
71pub struct RebaseResult {
72    /// Whether the rebase was successful
73    pub success: bool,
74    /// Old branch to new branch mapping
75    pub branch_mapping: HashMap<String, String>,
76    /// Commits that had conflicts
77    pub conflicts: Vec<String>,
78    /// New commit hashes
79    pub new_commits: Vec<String>,
80    /// Error message if rebase failed
81    pub error: Option<String>,
82    /// Summary of changes made
83    pub summary: String,
84}
85
86/// RAII guard to ensure temporary branches are cleaned up even on error/panic
87///
88/// This stores branch names and provides a cleanup method that can be called
89/// with a GitRepository reference. The Drop trait ensures cleanup happens
90/// even if the rebase function panics or returns early with an error.
91#[allow(dead_code)]
92struct TempBranchCleanupGuard {
93    branches: Vec<String>,
94    cleaned: bool,
95}
96
97#[allow(dead_code)]
98impl TempBranchCleanupGuard {
99    fn new() -> Self {
100        Self {
101            branches: Vec::new(),
102            cleaned: false,
103        }
104    }
105
106    fn add_branch(&mut self, branch: String) {
107        self.branches.push(branch);
108    }
109
110    /// Perform cleanup with provided git repository
111    fn cleanup(&mut self, git_repo: &GitRepository) {
112        if self.cleaned || self.branches.is_empty() {
113            return;
114        }
115
116        info!("๐Ÿงน Cleaning up {} temporary branches", self.branches.len());
117        for branch in &self.branches {
118            if let Err(e) = git_repo.delete_branch_unsafe(branch) {
119                warn!("Failed to delete temp branch {}: {}", branch, e);
120                // Continue with cleanup even if one fails
121            }
122        }
123        self.cleaned = true;
124    }
125}
126
127impl Drop for TempBranchCleanupGuard {
128    fn drop(&mut self) {
129        if !self.cleaned && !self.branches.is_empty() {
130            // This path is only hit on panic or unexpected early return
131            // We can't access git_repo here, so just log the branches that need manual cleanup
132            warn!(
133                "โš ๏ธ  {} temporary branches were not cleaned up: {}",
134                self.branches.len(),
135                self.branches.join(", ")
136            );
137            warn!("Run 'ca cleanup' to remove orphaned temporary branches");
138        }
139    }
140}
141
142/// Manages rebase operations for stacks
143pub struct RebaseManager {
144    stack_manager: StackManager,
145    git_repo: GitRepository,
146    options: RebaseOptions,
147    conflict_analyzer: ConflictAnalyzer,
148}
149
150impl Default for RebaseOptions {
151    fn default() -> Self {
152        Self {
153            strategy: RebaseStrategy::ForcePush,
154            interactive: false,
155            target_base: None,
156            preserve_merges: true,
157            auto_resolve: true,
158            max_retries: 3,
159            skip_pull: None,
160            original_working_branch: None,
161        }
162    }
163}
164
165impl RebaseManager {
166    /// Create a new rebase manager
167    pub fn new(
168        stack_manager: StackManager,
169        git_repo: GitRepository,
170        options: RebaseOptions,
171    ) -> Self {
172        Self {
173            stack_manager,
174            git_repo,
175            options,
176            conflict_analyzer: ConflictAnalyzer::new(),
177        }
178    }
179
180    /// Consume the rebase manager and return the updated stack manager
181    pub fn into_stack_manager(self) -> StackManager {
182        self.stack_manager
183    }
184
185    /// Rebase an entire stack onto a new base
186    pub fn rebase_stack(&mut self, stack_id: &Uuid) -> Result<RebaseResult> {
187        debug!("Starting rebase for stack {}", stack_id);
188
189        let stack = self
190            .stack_manager
191            .get_stack(stack_id)
192            .ok_or_else(|| CascadeError::config(format!("Stack {stack_id} not found")))?
193            .clone();
194
195        match self.options.strategy {
196            RebaseStrategy::ForcePush => self.rebase_with_force_push(&stack),
197            RebaseStrategy::Interactive => self.rebase_interactive(&stack),
198        }
199    }
200
201    /// Rebase using force-push strategy (industry standard for stacked diffs)
202    /// This updates local branches in-place, then force-pushes ONLY branches with existing PRs
203    /// to preserve PR history - the approach used by Graphite, Phabricator, spr, etc.
204    fn rebase_with_force_push(&mut self, stack: &Stack) -> Result<RebaseResult> {
205        use crate::cli::output::Output;
206
207        // Check if there's an in-progress cherry-pick from a previous failed sync
208        if self.has_in_progress_cherry_pick()? {
209            return self.handle_in_progress_cherry_pick(stack);
210        }
211
212        Output::section(format!("Rebasing stack: {}", stack.name));
213
214        let mut result = RebaseResult {
215            success: true,
216            branch_mapping: HashMap::new(),
217            conflicts: Vec::new(),
218            new_commits: Vec::new(),
219            error: None,
220            summary: String::new(),
221        };
222
223        let target_base = self
224            .options
225            .target_base
226            .as_ref()
227            .unwrap_or(&stack.base_branch)
228            .clone(); // Clone to avoid borrow issues
229
230        // Use the original working branch passed in options, or detect current branch
231        // CRITICAL: sync_stack passes the original branch before it checks out to base
232        // This prevents us from thinking we started on the base branch
233        let original_branch = self
234            .options
235            .original_working_branch
236            .clone()
237            .or_else(|| self.git_repo.get_current_branch().ok());
238
239        // SAFETY: Warn if we're starting on the base branch (unusual but valid)
240        // This can happen if user manually runs rebase while on base branch
241        if let Some(ref orig) = original_branch {
242            if orig == &target_base {
243                debug!(
244                    "Original working branch is base branch '{}' - will skip working branch update",
245                    orig
246                );
247            }
248        }
249
250        // Note: Caller (sync_stack) has already checked out base branch when skip_pull=true
251        // Only pull if not already done by caller (like sync command)
252        if !self.options.skip_pull.unwrap_or(false) {
253            if let Err(e) = self.pull_latest_changes(&target_base) {
254                Output::warning(format!("Could not pull latest changes: {}", e));
255            }
256        }
257
258        // Reset working directory to clean state before rebase
259        if let Err(e) = self.git_repo.reset_to_head() {
260            Output::warning(format!("Could not reset working directory: {}", e));
261        }
262
263        let mut current_base = target_base.clone();
264        let entry_count = stack.entries.len();
265        let mut temp_branches: Vec<String> = Vec::new(); // Track temp branches for cleanup
266        let mut branches_to_push: Vec<(String, String)> = Vec::new(); // (branch_name, pr_number)
267
268        println!(); // Spacing before tree
269        let plural = if entry_count == 1 { "entry" } else { "entries" };
270        println!("Rebasing {} {}...", entry_count, plural);
271
272        // Phase 1: Rebase all entries locally (libgit2 only - no CLI commands)
273        for (index, entry) in stack.entries.iter().enumerate() {
274            let original_branch = &entry.branch;
275
276            // Create a temporary branch from the current base
277            // This avoids committing directly to protected branches like develop/main
278            let temp_branch = format!("{}-temp-{}", original_branch, Utc::now().timestamp());
279            temp_branches.push(temp_branch.clone()); // Track for cleanup
280            self.git_repo
281                .create_branch(&temp_branch, Some(&current_base))?;
282            self.git_repo.checkout_branch(&temp_branch)?;
283
284            // Cherry-pick the commit onto the temp branch (NOT the protected base!)
285            match self.cherry_pick_commit(&entry.commit_hash) {
286                Ok(new_commit_hash) => {
287                    result.new_commits.push(new_commit_hash.clone());
288
289                    // Get the commit that's now at HEAD (the cherry-picked commit)
290                    let rebased_commit_id = self.git_repo.get_head_commit()?.id().to_string();
291
292                    // Update the original branch to point to this rebased commit
293                    // This is LOCAL ONLY - moves refs/heads/<branch> to the commit on temp branch
294                    self.git_repo
295                        .update_branch_to_commit(original_branch, &rebased_commit_id)?;
296
297                    // Track which branches need to be pushed (only those with PRs)
298                    let tree_char = if index + 1 == entry_count {
299                        "โ””โ”€"
300                    } else {
301                        "โ”œโ”€"
302                    };
303
304                    if let Some(pr_num) = &entry.pull_request_id {
305                        println!("   {} {} (PR #{})", tree_char, original_branch, pr_num);
306                        branches_to_push.push((original_branch.clone(), pr_num.clone()));
307                    } else {
308                        println!("   {} {} (not submitted)", tree_char, original_branch);
309                    }
310
311                    result
312                        .branch_mapping
313                        .insert(original_branch.clone(), original_branch.clone());
314
315                    // Update stack entry with new commit hash
316                    self.update_stack_entry(
317                        stack.id,
318                        &entry.id,
319                        original_branch,
320                        &rebased_commit_id,
321                    )?;
322
323                    // This branch becomes the base for the next entry
324                    current_base = original_branch.clone();
325                }
326                Err(e) => {
327                    println!(); // Spacing before error
328                    Output::error(format!("Conflict in {}: {}", &entry.commit_hash[..8], e));
329                    result.conflicts.push(entry.commit_hash.clone());
330
331                    if !self.options.auto_resolve {
332                        result.success = false;
333                        result.error = Some(format!(
334                            "Conflict in {}: {}\n\n\
335                            MANUAL CONFLICT RESOLUTION REQUIRED\n\
336                            =====================================\n\n\
337                            Step 1: Analyze conflicts\n\
338                            โ†’ Run: ca conflicts\n\
339                            โ†’ This shows which conflicts are in which files\n\n\
340                            Step 2: Resolve conflicts in your editor\n\
341                            โ†’ Open conflicted files and edit them\n\
342                            โ†’ Remove conflict markers (<<<<<<, ======, >>>>>>)\n\
343                            โ†’ Keep the code you want\n\
344                            โ†’ Save the files\n\n\
345                            Step 3: Mark conflicts as resolved\n\
346                            โ†’ Run: git add <resolved-files>\n\
347                            โ†’ Or: git add -A (to stage all resolved files)\n\n\
348                            Step 4: Complete the sync\n\
349                            โ†’ Run: ca sync\n\
350                            โ†’ Cascade will detect resolved conflicts and continue\n\n\
351                            Alternative: Abort and start over\n\
352                            โ†’ Run: git cherry-pick --abort\n\
353                            โ†’ Then: ca sync (starts fresh)\n\n\
354                            TIP: Enable auto-resolution for simple conflicts:\n\
355                            โ†’ Run: ca sync --auto-resolve\n\
356                            โ†’ Only complex conflicts will require manual resolution",
357                            entry.commit_hash, e
358                        ));
359                        break;
360                    }
361
362                    // Try to resolve automatically
363                    match self.auto_resolve_conflicts(&entry.commit_hash) {
364                        Ok(fully_resolved) => {
365                            if !fully_resolved {
366                                result.success = false;
367                                result.error = Some(format!(
368                                    "Could not auto-resolve all conflicts in {}\n\n\
369                                    MANUAL CONFLICT RESOLUTION REQUIRED\n\
370                                    =====================================\n\n\
371                                    Some conflicts are too complex for auto-resolution.\n\n\
372                                    Step 1: Analyze remaining conflicts\n\
373                                    โ†’ Run: ca conflicts\n\
374                                    โ†’ Shows which files still have conflicts\n\
375                                    โ†’ Use --detailed flag for more info\n\n\
376                                    Step 2: Resolve conflicts in your editor\n\
377                                    โ†’ Open conflicted files (marked with โœ‹ in ca conflicts output)\n\
378                                    โ†’ Remove conflict markers (<<<<<<, ======, >>>>>>)\n\
379                                    โ†’ Keep the code you want\n\
380                                    โ†’ Save the files\n\n\
381                                    Step 3: Mark conflicts as resolved\n\
382                                    โ†’ Run: git add <resolved-files>\n\
383                                    โ†’ Or: git add -A (to stage all resolved files)\n\n\
384                                    Step 4: Complete the sync\n\
385                                    โ†’ Run: ca sync\n\
386                                    โ†’ Cascade will continue from where it left off\n\n\
387                                    Alternative: Abort and start over\n\
388                                    โ†’ Run: git cherry-pick --abort\n\
389                                    โ†’ Then: ca sync (starts fresh)\n\n\
390                                    BACKUP: If auto-resolution was wrong\n\
391                                    โ†’ Check for .cascade-backup files in your repo\n\
392                                    โ†’ These contain the original file content before auto-resolution",
393                                    &entry.commit_hash[..8]
394                                ));
395                                break;
396                            }
397
398                            // Commit the resolved changes
399                            let commit_message =
400                                format!("Auto-resolved conflicts in {}", &entry.commit_hash[..8]);
401                            
402                            // CRITICAL: Check if there are actually changes to commit
403                            warn!("AUTO-RESOLVE DEBUG: About to commit. Checking staged files...");
404                            let staged_files = self.git_repo.get_staged_files()?;
405                            
406                            if staged_files.is_empty() {
407                                // NO FILES STAGED! This means auto-resolve didn't actually stage anything
408                                // This is the bug - cherry-pick failed, but has_conflicts() returned false
409                                // so auto-resolve exited early without staging anything
410                                result.success = false;
411                                result.error = Some(format!(
412                                    "CRITICAL BUG DETECTED: Cherry-pick failed but no files were staged!\n\n\
413                                    This indicates a Git state issue after cherry-pick failure.\n\n\
414                                    RECOVERY STEPS:\n\
415                                    ================\n\n\
416                                    Step 1: Check Git status\n\
417                                    โ†’ Run: git status\n\
418                                    โ†’ Check if there are any changes in working directory\n\n\
419                                    Step 2: Check for conflicts manually\n\
420                                    โ†’ Run: git diff\n\
421                                    โ†’ Look for conflict markers (<<<<<<, ======, >>>>>>)\n\n\
422                                    Step 3: Abort the cherry-pick\n\
423                                    โ†’ Run: git cherry-pick --abort\n\n\
424                                    Step 4: Report this bug\n\
425                                    โ†’ This is a known issue we're investigating\n\
426                                    โ†’ Cherry-pick failed for commit {}\n\
427                                    โ†’ But Git reported no conflicts and no staged files\n\n\
428                                    Step 5: Try manual resolution\n\
429                                    โ†’ Run: ca sync --no-auto-resolve\n\
430                                    โ†’ Manually resolve conflicts as they appear",
431                                    &entry.commit_hash[..8]
432                                ));
433                                warn!("AUTO-RESOLVE DEBUG: CRITICAL - No files staged after auto-resolve!");
434                                break;
435                            }
436                            
437                            // DEBUG: Show what's staged
438                            warn!("AUTO-RESOLVE DEBUG: {} files staged: {:?}", staged_files.len(), staged_files);
439                            if let Ok(status) = std::process::Command::new("git")
440                                .args(["diff", "--cached", "--stat"])
441                                .current_dir(self.git_repo.path())
442                                .output()
443                            {
444                                let stat_output = String::from_utf8_lossy(&status.stdout);
445                                warn!("AUTO-RESOLVE DEBUG: Staged changes:\n{}", stat_output);
446                            }
447                            
448                            match self.git_repo.commit(&commit_message) {
449                                Ok(new_commit_id) => {
450                                    warn!(
451                                        "AUTO-RESOLVE DEBUG: Created commit {} with message '{}'",
452                                        &new_commit_id[..8],
453                                        commit_message
454                                    );
455                                    
456                                    // DEBUG: Check what's in the commit
457                                    if let Ok(show) = std::process::Command::new("git")
458                                        .args(["show", "--stat", &new_commit_id])
459                                        .current_dir(self.git_repo.path())
460                                        .output()
461                                    {
462                                        let show_output = String::from_utf8_lossy(&show.stdout);
463                                        warn!("AUTO-RESOLVE DEBUG: Commit contents:\n{}", show_output);
464                                    }
465                                    
466                                    Output::success("Auto-resolved conflicts");
467                                    result.new_commits.push(new_commit_id.clone());
468                                    let rebased_commit_id = new_commit_id;
469
470                                    // Update the original branch to point to this rebased commit
471                                    self.git_repo.update_branch_to_commit(
472                                        original_branch,
473                                        &rebased_commit_id,
474                                    )?;
475
476                                    // Track which branches need to be pushed (only those with PRs)
477                                    let tree_char = if index + 1 == entry_count {
478                                        "โ””โ”€"
479                                    } else {
480                                        "โ”œโ”€"
481                                    };
482
483                                    if let Some(pr_num) = &entry.pull_request_id {
484                                        println!(
485                                            "   {} {} (PR #{})",
486                                            tree_char, original_branch, pr_num
487                                        );
488                                        branches_to_push
489                                            .push((original_branch.clone(), pr_num.clone()));
490                                    } else {
491                                        println!(
492                                            "   {} {} (not submitted)",
493                                            tree_char, original_branch
494                                        );
495                                    }
496
497                                    result
498                                        .branch_mapping
499                                        .insert(original_branch.clone(), original_branch.clone());
500
501                                    // Update stack entry with new commit hash
502                                    self.update_stack_entry(
503                                        stack.id,
504                                        &entry.id,
505                                        original_branch,
506                                        &rebased_commit_id,
507                                    )?;
508
509                                    // This branch becomes the base for the next entry
510                                    current_base = original_branch.clone();
511                                }
512                                Err(commit_err) => {
513                                    result.success = false;
514                                    result.error = Some(format!(
515                                        "Could not commit auto-resolved conflicts: {}\n\n\
516                                        This usually means:\n\
517                                        - Git index is locked (another process accessing repo)\n\
518                                        - File permissions issue\n\
519                                        - Disk space issue\n\n\
520                                        Recovery:\n\
521                                        1. Check if another Git operation is running\n\
522                                        2. Run 'rm -f .git/index.lock' if stale lock exists\n\
523                                        3. Run 'git status' to check repo state\n\
524                                        4. Retry 'ca sync' after fixing the issue",
525                                        commit_err
526                                    ));
527                                    break;
528                                }
529                            }
530                        }
531                        Err(resolve_err) => {
532                            result.success = false;
533                            result.error = Some(format!(
534                                "Could not resolve conflicts: {}\n\n\
535                                Recovery:\n\
536                                1. Check repo state: 'git status'\n\
537                                2. If files are staged, commit or reset them: 'git reset --hard HEAD'\n\
538                                3. Remove any lock files: 'rm -f .git/index.lock'\n\
539                                4. Retry 'ca sync'",
540                                resolve_err
541                            ));
542                            break;
543                        }
544                    }
545                }
546            }
547        }
548
549        // Cleanup temp branches before returning to original branch
550        // Must checkout away from temp branches first
551        if !temp_branches.is_empty() {
552            // Force checkout to base branch to allow temp branch deletion
553            // Use unsafe checkout to bypass safety checks since we know this is cleanup
554            if let Err(e) = self.git_repo.checkout_branch_unsafe(&target_base) {
555                Output::warning(format!("Could not checkout base for cleanup: {}", e));
556                // If we can't checkout, we can't delete temp branches
557                // This is non-critical - temp branches will be cleaned up eventually
558            } else {
559                // Successfully checked out - now delete temp branches
560                for temp_branch in &temp_branches {
561                    if let Err(e) = self.git_repo.delete_branch_unsafe(temp_branch) {
562                        debug!("Could not delete temp branch {}: {}", temp_branch, e);
563                    }
564                }
565            }
566        }
567
568        // Phase 2: Push all branches with PRs to remote (git CLI - after all libgit2 operations)
569        // This batch approach prevents index lock conflicts between libgit2 and git CLI
570        let pushed_count = branches_to_push.len();
571        let skipped_count = entry_count - pushed_count;
572
573        if !branches_to_push.is_empty() {
574            println!(); // Spacing before push phase
575            println!(
576                "Pushing {} branch{} to remote...",
577                pushed_count,
578                if pushed_count == 1 { "" } else { "es" }
579            );
580
581            for (branch_name, _pr_num) in &branches_to_push {
582                match self.git_repo.force_push_single_branch_auto(branch_name) {
583                    Ok(_) => {
584                        debug!("Pushed {} successfully", branch_name);
585                    }
586                    Err(e) => {
587                        Output::warning(format!("Could not push '{}': {}", branch_name, e));
588                        // Continue pushing other branches even if one fails
589                    }
590                }
591            }
592        }
593
594        // Update working branch to point to the top of the rebased stack
595        // This ensures subsequent `ca push` doesn't re-add old commits
596        if let Some(ref orig_branch) = original_branch {
597            // CRITICAL: Never update the base branch! Only update working branches
598            if orig_branch != &target_base {
599                // Get the last entry's branch (top of stack)
600                if let Some(last_entry) = stack.entries.last() {
601                    let top_branch = &last_entry.branch;
602
603                    // Force-update working branch to point to same commit as top entry
604                    if let Ok(top_commit) = self.git_repo.get_branch_head(top_branch) {
605                        debug!(
606                            "Updating working branch '{}' to match top of stack ({})",
607                            orig_branch,
608                            &top_commit[..8]
609                        );
610
611                        if let Err(e) = self
612                            .git_repo
613                            .update_branch_to_commit(orig_branch, &top_commit)
614                        {
615                            Output::warning(format!(
616                                "Could not update working branch '{}' to top of stack: {}",
617                                orig_branch, e
618                            ));
619                        }
620                    }
621                }
622
623                // Return to original working branch
624                // Use unsafe checkout to force it (we're in cleanup phase, no uncommitted changes)
625                if let Err(e) = self.git_repo.checkout_branch_unsafe(orig_branch) {
626                    debug!(
627                        "Could not return to original branch '{}': {}",
628                        orig_branch, e
629                    );
630                    // Non-critical: User is left on base branch instead of working branch
631                }
632            } else {
633                // User was on base branch - this is unusual but valid
634                // Don't update base branch, just checkout back to it
635                debug!(
636                    "Skipping working branch update - user was on base branch '{}'",
637                    orig_branch
638                );
639                if let Err(e) = self.git_repo.checkout_branch_unsafe(orig_branch) {
640                    debug!("Could not return to base branch '{}': {}", orig_branch, e);
641                }
642            }
643        }
644
645        // Build summary message
646        result.summary = if pushed_count > 0 {
647            let pr_plural = if pushed_count == 1 { "" } else { "s" };
648            let entry_plural = if entry_count == 1 { "entry" } else { "entries" };
649
650            if skipped_count > 0 {
651                format!(
652                    "{} {} rebased ({} PR{} updated, {} not yet submitted)",
653                    entry_count, entry_plural, pushed_count, pr_plural, skipped_count
654                )
655            } else {
656                format!(
657                    "{} {} rebased ({} PR{} updated)",
658                    entry_count, entry_plural, pushed_count, pr_plural
659                )
660            }
661        } else {
662            let plural = if entry_count == 1 { "entry" } else { "entries" };
663            format!("{} {} rebased (no PRs to update yet)", entry_count, plural)
664        };
665
666        // Display result with proper formatting
667        println!(); // Spacing after tree
668        if result.success {
669            Output::success(&result.summary);
670        } else {
671            Output::error(format!("Rebase failed: {:?}", result.error));
672        }
673
674        // Save the updated stack metadata to disk
675        self.stack_manager.save_to_disk()?;
676
677        Ok(result)
678    }
679
680    /// Interactive rebase with user input
681    fn rebase_interactive(&mut self, stack: &Stack) -> Result<RebaseResult> {
682        info!("Starting interactive rebase for stack '{}'", stack.name);
683
684        let mut result = RebaseResult {
685            success: true,
686            branch_mapping: HashMap::new(),
687            conflicts: Vec::new(),
688            new_commits: Vec::new(),
689            error: None,
690            summary: String::new(),
691        };
692
693        println!("Interactive Rebase for Stack: {}", stack.name);
694        println!("   Base branch: {}", stack.base_branch);
695        println!("   Entries: {}", stack.entries.len());
696
697        if self.options.interactive {
698            println!("\nChoose action for each commit:");
699            println!("  (p)ick   - apply the commit");
700            println!("  (s)kip   - skip this commit");
701            println!("  (e)dit   - edit the commit message");
702            println!("  (q)uit   - abort the rebase");
703        }
704
705        // For now, automatically pick all commits
706        // In a real implementation, this would prompt the user
707        for entry in &stack.entries {
708            println!(
709                "  {} {} - {}",
710                entry.short_hash(),
711                entry.branch,
712                entry.short_message(50)
713            );
714
715            // Auto-pick for demo purposes
716            match self.cherry_pick_commit(&entry.commit_hash) {
717                Ok(new_commit) => result.new_commits.push(new_commit),
718                Err(_) => result.conflicts.push(entry.commit_hash.clone()),
719            }
720        }
721
722        result.summary = format!(
723            "Interactive rebase processed {} commits",
724            stack.entries.len()
725        );
726        Ok(result)
727    }
728
729    /// Cherry-pick a commit onto the current branch
730    fn cherry_pick_commit(&self, commit_hash: &str) -> Result<String> {
731        // Use the real cherry-pick implementation from GitRepository
732        let new_commit_hash = self.git_repo.cherry_pick(commit_hash)?;
733
734        // Check for any leftover staged changes after successful cherry-pick
735        if let Ok(staged_files) = self.git_repo.get_staged_files() {
736            if !staged_files.is_empty() {
737                // Commit any leftover staged changes silently
738                let cleanup_message = format!("Cleanup after cherry-pick {}", &commit_hash[..8]);
739                let _ = self.git_repo.commit_staged_changes(&cleanup_message);
740            }
741        }
742
743        Ok(new_commit_hash)
744    }
745
746    /// Attempt to automatically resolve conflicts
747    fn auto_resolve_conflicts(&self, commit_hash: &str) -> Result<bool> {
748        warn!("=== AUTO-RESOLVE DEBUG: Starting for commit {} ===", commit_hash);
749
750        // Check if there are actually conflicts
751        let has_conflicts = self.git_repo.has_conflicts()?;
752        warn!("AUTO-RESOLVE DEBUG: has_conflicts() = {}", has_conflicts);
753        
754        // CRITICAL DEBUG: Check working directory state
755        if let Ok(status_output) = std::process::Command::new("git")
756            .args(["status", "--short"])
757            .current_dir(self.git_repo.path())
758            .output()
759        {
760            let status_str = String::from_utf8_lossy(&status_output.stdout);
761            warn!("AUTO-RESOLVE DEBUG: git status --short:\n{}", status_str);
762        }
763        
764        // Check if cherry-pick is in progress
765        let cherry_pick_head = self.git_repo.path().join(".git").join("CHERRY_PICK_HEAD");
766        let cherry_pick_in_progress = cherry_pick_head.exists();
767        warn!("AUTO-RESOLVE DEBUG: CHERRY_PICK_HEAD exists = {}", cherry_pick_in_progress);
768        
769        if !has_conflicts {
770            warn!("AUTO-RESOLVE DEBUG: No conflicts detected by Git index");
771            warn!("AUTO-RESOLVE DEBUG: But cherry-pick may have failed - checking working directory...");
772            
773            // If cherry-pick is in progress but no conflicts detected, something is wrong
774            if cherry_pick_in_progress {
775                warn!("AUTO-RESOLVE DEBUG: CHERRY_PICK_HEAD exists but no conflicts in index!");
776                warn!("AUTO-RESOLVE DEBUG: This indicates a Git state issue - aborting cherry-pick");
777                
778                // Abort the cherry-pick to clean up
779                let _ = std::process::Command::new("git")
780                    .args(["cherry-pick", "--abort"])
781                    .current_dir(self.git_repo.path())
782                    .output();
783                
784                return Err(CascadeError::Branch(format!(
785                    "Cherry-pick failed for {} but Git index shows no conflicts. \
786                     This usually means the cherry-pick was aborted or failed in an unexpected way. \
787                     Please try manual resolution.",
788                    &commit_hash[..8]
789                )));
790            }
791            
792            return Ok(true);
793        }
794
795        let conflicted_files = self.git_repo.get_conflicted_files()?;
796
797        if conflicted_files.is_empty() {
798            warn!("AUTO-RESOLVE DEBUG: Conflicted files list is empty");
799            return Ok(true);
800        }
801
802        warn!(
803            "AUTO-RESOLVE DEBUG: Found conflicts in {} files: {:?}",
804            conflicted_files.len(),
805            conflicted_files
806        );
807
808        // Use the new conflict analyzer for detailed analysis
809        let analysis = self
810            .conflict_analyzer
811            .analyze_conflicts(&conflicted_files, self.git_repo.path())?;
812
813        info!(
814            "๐Ÿ” Conflict analysis: {} total conflicts, {} auto-resolvable",
815            analysis.total_conflicts, analysis.auto_resolvable_count
816        );
817
818        // Display recommendations
819        for recommendation in &analysis.recommendations {
820            info!("๐Ÿ’ก {}", recommendation);
821        }
822
823        let mut resolved_count = 0;
824        let mut resolved_files = Vec::new(); // Track which files were actually resolved
825        let mut failed_files = Vec::new();
826
827        for file_analysis in &analysis.files {
828            warn!(
829                "AUTO-RESOLVE DEBUG: Processing file: {} (auto_resolvable: {}, conflicts: {})",
830                file_analysis.file_path,
831                file_analysis.auto_resolvable,
832                file_analysis.conflicts.len()
833            );
834
835            if file_analysis.auto_resolvable {
836                match self.resolve_file_conflicts_enhanced(
837                    &file_analysis.file_path,
838                    &file_analysis.conflicts,
839                ) {
840                    Ok(ConflictResolution::Resolved) => {
841                        resolved_count += 1;
842                        resolved_files.push(file_analysis.file_path.clone());
843                        warn!(
844                            "AUTO-RESOLVE DEBUG: Successfully resolved {}",
845                            file_analysis.file_path
846                        );
847                    }
848                    Ok(ConflictResolution::TooComplex) => {
849                        warn!(
850                            "AUTO-RESOLVE DEBUG: {} too complex for auto-resolution",
851                            file_analysis.file_path
852                        );
853                        failed_files.push(file_analysis.file_path.clone());
854                    }
855                    Err(e) => {
856                        warn!(
857                            "AUTO-RESOLVE DEBUG: Failed to resolve {}: {}",
858                            file_analysis.file_path, e
859                        );
860                        failed_files.push(file_analysis.file_path.clone());
861                    }
862                }
863            } else {
864                failed_files.push(file_analysis.file_path.clone());
865                warn!(
866                    "AUTO-RESOLVE DEBUG: {} requires manual resolution ({} conflicts)",
867                    file_analysis.file_path,
868                    file_analysis.conflicts.len()
869                );
870            }
871        }
872
873        if resolved_count > 0 {
874            warn!(
875                "AUTO-RESOLVE DEBUG: Resolved {}/{} files",
876                resolved_count,
877                conflicted_files.len()
878            );
879            warn!("AUTO-RESOLVE DEBUG: Resolved files: {:?}", resolved_files);
880
881            // CRITICAL: Only stage files that were successfully resolved
882            // This prevents staging files that still have conflict markers
883            let file_paths: Vec<&str> = resolved_files.iter().map(|s| s.as_str()).collect();
884            warn!("AUTO-RESOLVE DEBUG: Staging {} files", file_paths.len());
885            self.git_repo.stage_files(&file_paths)?;
886            warn!("AUTO-RESOLVE DEBUG: Files staged successfully");
887        } else {
888            warn!("AUTO-RESOLVE DEBUG: No files were resolved (resolved_count = 0)");
889        }
890
891        // Return true only if ALL conflicts were resolved
892        let all_resolved = failed_files.is_empty();
893
894        warn!(
895            "AUTO-RESOLVE DEBUG: all_resolved = {}, failed_files = {:?}",
896            all_resolved, failed_files
897        );
898
899        if !all_resolved {
900            warn!(
901                "AUTO-RESOLVE DEBUG: {} files still need manual resolution",
902                failed_files.len()
903            );
904        }
905
906        warn!("AUTO-RESOLVE DEBUG: Returning all_resolved = {}", all_resolved);
907        Ok(all_resolved)
908    }
909
910    /// Resolve conflicts using enhanced analysis
911    fn resolve_file_conflicts_enhanced(
912        &self,
913        file_path: &str,
914        conflicts: &[crate::git::ConflictRegion],
915    ) -> Result<ConflictResolution> {
916        let repo_path = self.git_repo.path();
917        let full_path = repo_path.join(file_path);
918
919        // Read the file content with conflict markers
920        let mut content = std::fs::read_to_string(&full_path)
921            .map_err(|e| CascadeError::config(format!("Failed to read file {file_path}: {e}")))?;
922
923        if conflicts.is_empty() {
924            return Ok(ConflictResolution::Resolved);
925        }
926
927        info!(
928            "Resolving {} conflicts in {} using enhanced analysis",
929            conflicts.len(),
930            file_path
931        );
932
933        let mut any_resolved = false;
934
935        // Process conflicts in reverse order to maintain string indices
936        for conflict in conflicts.iter().rev() {
937            match self.resolve_single_conflict_enhanced(conflict) {
938                Ok(Some(resolution)) => {
939                    // Replace the conflict region with the resolved content
940                    let before = &content[..conflict.start_pos];
941                    let after = &content[conflict.end_pos..];
942                    content = format!("{before}{resolution}{after}");
943                    any_resolved = true;
944                    debug!(
945                        "โœ… Resolved {} conflict at lines {}-{} in {}",
946                        format!("{:?}", conflict.conflict_type).to_lowercase(),
947                        conflict.start_line,
948                        conflict.end_line,
949                        file_path
950                    );
951                }
952                Ok(None) => {
953                    debug!(
954                        "โš ๏ธ  {} conflict at lines {}-{} in {} requires manual resolution",
955                        format!("{:?}", conflict.conflict_type).to_lowercase(),
956                        conflict.start_line,
957                        conflict.end_line,
958                        file_path
959                    );
960                    return Ok(ConflictResolution::TooComplex);
961                }
962                Err(e) => {
963                    debug!("โŒ Failed to resolve conflict in {}: {}", file_path, e);
964                    return Ok(ConflictResolution::TooComplex);
965                }
966            }
967        }
968
969        if any_resolved {
970            // Check if we resolved ALL conflicts in this file
971            let remaining_conflicts = self.parse_conflict_markers(&content)?;
972
973            if remaining_conflicts.is_empty() {
974                warn!(
975                    "AUTO-RESOLVE DEBUG: All conflicts resolved in {}, content length: {} bytes",
976                    file_path,
977                    content.len()
978                );
979
980                // CRITICAL SAFETY CHECK: Don't write empty files!
981                if content.trim().is_empty() {
982                    warn!(
983                        "AUTO-RESOLVE DEBUG: SAFETY CHECK TRIGGERED! Resolved content for {} is empty! Aborting.",
984                        file_path
985                    );
986                    return Ok(ConflictResolution::TooComplex);
987                }
988
989                // SAFETY: Create backup before writing resolved content
990                let backup_path = full_path.with_extension("cascade-backup");
991                if let Ok(original_content) = std::fs::read_to_string(&full_path) {
992                    warn!(
993                        "AUTO-RESOLVE DEBUG: Backup for {} (original: {} bytes, resolved: {} bytes)",
994                        file_path,
995                        original_content.len(),
996                        content.len()
997                    );
998                    let _ = std::fs::write(&backup_path, original_content);
999                }
1000
1001                // All conflicts resolved - write the file back atomically
1002                crate::utils::atomic_file::write_string(&full_path, &content)?;
1003
1004                warn!(
1005                    "AUTO-RESOLVE DEBUG: Wrote {} bytes to {}",
1006                    content.len(),
1007                    file_path
1008                );
1009                return Ok(ConflictResolution::Resolved);
1010            } else {
1011                info!(
1012                    "โš ๏ธ  Partially resolved conflicts in {} ({} remaining)",
1013                    file_path,
1014                    remaining_conflicts.len()
1015                );
1016            }
1017        }
1018
1019        Ok(ConflictResolution::TooComplex)
1020    }
1021
1022    /// Helper to count whitespace consistency (lower is better)
1023    #[allow(dead_code)]
1024    fn count_whitespace_consistency(content: &str) -> usize {
1025        let mut inconsistencies = 0;
1026        let lines: Vec<&str> = content.lines().collect();
1027
1028        for line in &lines {
1029            // Check for mixed tabs and spaces
1030            if line.contains('\t') && line.contains(' ') {
1031                inconsistencies += 1;
1032            }
1033        }
1034
1035        // Penalize for inconsistencies
1036        lines.len().saturating_sub(inconsistencies)
1037    }
1038
1039    /// Resolve a single conflict using enhanced analysis
1040    fn resolve_single_conflict_enhanced(
1041        &self,
1042        conflict: &crate::git::ConflictRegion,
1043    ) -> Result<Option<String>> {
1044        debug!(
1045            "Resolving {} conflict in {} (lines {}-{})",
1046            format!("{:?}", conflict.conflict_type).to_lowercase(),
1047            conflict.file_path,
1048            conflict.start_line,
1049            conflict.end_line
1050        );
1051
1052        use crate::git::ConflictType;
1053
1054        match conflict.conflict_type {
1055            ConflictType::Whitespace => {
1056                // SAFETY: Only resolve if the content is truly identical except for whitespace
1057                // Otherwise, it might be intentional formatting changes
1058                let our_normalized = conflict
1059                    .our_content
1060                    .split_whitespace()
1061                    .collect::<Vec<_>>()
1062                    .join(" ");
1063                let their_normalized = conflict
1064                    .their_content
1065                    .split_whitespace()
1066                    .collect::<Vec<_>>()
1067                    .join(" ");
1068
1069                if our_normalized == their_normalized {
1070                    // Content is identical - in cherry-pick context, ALWAYS prefer THEIRS
1071                    // CRITICAL: In cherry-pick, OURS=base branch, THEIRS=commit being applied
1072                    // We must keep the commit's changes (THEIRS), not the base (OURS)
1073                    // Otherwise we delete the user's code!
1074                    Ok(Some(conflict.their_content.clone()))
1075                } else {
1076                    // Content differs beyond whitespace - not safe to auto-resolve
1077                    debug!(
1078                        "Whitespace conflict has content differences - requires manual resolution"
1079                    );
1080                    Ok(None)
1081                }
1082            }
1083            ConflictType::LineEnding => {
1084                // Normalize to Unix line endings
1085                let normalized = conflict
1086                    .our_content
1087                    .replace("\r\n", "\n")
1088                    .replace('\r', "\n");
1089                Ok(Some(normalized))
1090            }
1091            ConflictType::PureAddition => {
1092                // CRITICAL: In cherry-pick, OURS=base, THEIRS=commit being applied
1093                // We must respect what the commit does (THEIRS), not what the base has (OURS)
1094
1095                if conflict.our_content.is_empty() && !conflict.their_content.is_empty() {
1096                    // Base is empty, commit adds content โ†’ keep the addition
1097                    Ok(Some(conflict.their_content.clone()))
1098                } else if conflict.their_content.is_empty() && !conflict.our_content.is_empty() {
1099                    // Base has content, commit removes it โ†’ keep it removed (empty)
1100                    Ok(Some(String::new()))
1101                } else if conflict.our_content.is_empty() && conflict.their_content.is_empty() {
1102                    // Both empty โ†’ keep empty
1103                    Ok(Some(String::new()))
1104                } else {
1105                    // Both sides have content - this could be:
1106                    // - Duplicate function definitions
1107                    // - Conflicting logic
1108                    // - Different implementations of same feature
1109                    // Too risky to auto-merge - require manual resolution
1110                    debug!(
1111                        "PureAddition conflict has content on both sides - requires manual resolution"
1112                    );
1113                    Ok(None)
1114                }
1115            }
1116            ConflictType::ImportMerge => {
1117                // SAFETY: Only merge simple single-line imports
1118                // Multi-line imports or complex cases require manual resolution
1119
1120                // Check if all imports are single-line and look like imports
1121                let our_lines: Vec<&str> = conflict.our_content.lines().collect();
1122                let their_lines: Vec<&str> = conflict.their_content.lines().collect();
1123
1124                // Verify all lines look like simple imports (heuristic check)
1125                let all_simple = our_lines.iter().chain(their_lines.iter()).all(|line| {
1126                    let trimmed = line.trim();
1127                    trimmed.starts_with("import ")
1128                        || trimmed.starts_with("from ")
1129                        || trimmed.starts_with("use ")
1130                        || trimmed.starts_with("#include")
1131                        || trimmed.is_empty()
1132                });
1133
1134                if !all_simple {
1135                    debug!("ImportMerge contains non-import lines - requires manual resolution");
1136                    return Ok(None);
1137                }
1138
1139                // Merge and deduplicate imports
1140                let mut all_imports: Vec<&str> = our_lines
1141                    .into_iter()
1142                    .chain(their_lines)
1143                    .filter(|line| !line.trim().is_empty())
1144                    .collect();
1145                all_imports.sort();
1146                all_imports.dedup();
1147                Ok(Some(all_imports.join("\n")))
1148            }
1149            ConflictType::Structural | ConflictType::ContentOverlap | ConflictType::Complex => {
1150                // These require manual resolution
1151                Ok(None)
1152            }
1153        }
1154    }
1155
1156    /// Parse conflict markers from file content
1157    fn parse_conflict_markers(&self, content: &str) -> Result<Vec<ConflictRegion>> {
1158        let lines: Vec<&str> = content.lines().collect();
1159        let mut conflicts = Vec::new();
1160        let mut i = 0;
1161
1162        while i < lines.len() {
1163            if lines[i].starts_with("<<<<<<<") {
1164                // Found start of conflict
1165                let start_line = i + 1;
1166                let mut separator_line = None;
1167                let mut end_line = None;
1168
1169                // Find the separator and end
1170                for (j, line) in lines.iter().enumerate().skip(i + 1) {
1171                    if line.starts_with("=======") {
1172                        separator_line = Some(j + 1);
1173                    } else if line.starts_with(">>>>>>>") {
1174                        end_line = Some(j + 1);
1175                        break;
1176                    }
1177                }
1178
1179                if let (Some(sep), Some(end)) = (separator_line, end_line) {
1180                    // Calculate byte positions
1181                    let start_pos = lines[..i].iter().map(|l| l.len() + 1).sum::<usize>();
1182                    let end_pos = lines[..end].iter().map(|l| l.len() + 1).sum::<usize>();
1183
1184                    let our_content = lines[(i + 1)..(sep - 1)].join("\n");
1185                    let their_content = lines[sep..(end - 1)].join("\n");
1186
1187                    conflicts.push(ConflictRegion {
1188                        start: start_pos,
1189                        end: end_pos,
1190                        start_line,
1191                        end_line: end,
1192                        our_content,
1193                        their_content,
1194                    });
1195
1196                    i = end;
1197                } else {
1198                    i += 1;
1199                }
1200            } else {
1201                i += 1;
1202            }
1203        }
1204
1205        Ok(conflicts)
1206    }
1207
1208    /// Resolve a single conflict using smart strategies
1209    fn resolve_single_conflict(
1210        &self,
1211        conflict: &ConflictRegion,
1212        file_path: &str,
1213    ) -> Result<Option<String>> {
1214        debug!(
1215            "Analyzing conflict in {} (lines {}-{})",
1216            file_path, conflict.start_line, conflict.end_line
1217        );
1218
1219        // Strategy 1: Whitespace-only differences
1220        if let Some(resolved) = self.resolve_whitespace_conflict(conflict)? {
1221            debug!("Resolved as whitespace-only conflict");
1222            return Ok(Some(resolved));
1223        }
1224
1225        // Strategy 2: Line ending differences
1226        if let Some(resolved) = self.resolve_line_ending_conflict(conflict)? {
1227            debug!("Resolved as line ending conflict");
1228            return Ok(Some(resolved));
1229        }
1230
1231        // Strategy 3: Pure addition conflicts (no overlapping changes)
1232        if let Some(resolved) = self.resolve_addition_conflict(conflict)? {
1233            debug!("Resolved as pure addition conflict");
1234            return Ok(Some(resolved));
1235        }
1236
1237        // Strategy 4: Import/dependency reordering
1238        if let Some(resolved) = self.resolve_import_conflict(conflict, file_path)? {
1239            debug!("Resolved as import reordering conflict");
1240            return Ok(Some(resolved));
1241        }
1242
1243        // No strategy could resolve this conflict
1244        Ok(None)
1245    }
1246
1247    /// Resolve conflicts that only differ by whitespace
1248    fn resolve_whitespace_conflict(&self, conflict: &ConflictRegion) -> Result<Option<String>> {
1249        let our_normalized = self.normalize_whitespace(&conflict.our_content);
1250        let their_normalized = self.normalize_whitespace(&conflict.their_content);
1251
1252        if our_normalized == their_normalized {
1253            // Only whitespace differences - prefer the version with better formatting
1254            let resolved =
1255                if conflict.our_content.trim().len() >= conflict.their_content.trim().len() {
1256                    conflict.our_content.clone()
1257                } else {
1258                    conflict.their_content.clone()
1259                };
1260
1261            return Ok(Some(resolved));
1262        }
1263
1264        Ok(None)
1265    }
1266
1267    /// Resolve conflicts that only differ by line endings
1268    fn resolve_line_ending_conflict(&self, conflict: &ConflictRegion) -> Result<Option<String>> {
1269        let our_normalized = conflict
1270            .our_content
1271            .replace("\r\n", "\n")
1272            .replace('\r', "\n");
1273        let their_normalized = conflict
1274            .their_content
1275            .replace("\r\n", "\n")
1276            .replace('\r', "\n");
1277
1278        if our_normalized == their_normalized {
1279            // Only line ending differences - prefer Unix line endings
1280            return Ok(Some(our_normalized));
1281        }
1282
1283        Ok(None)
1284    }
1285
1286    /// Resolve conflicts where both sides only add lines (no overlapping edits)
1287    fn resolve_addition_conflict(&self, conflict: &ConflictRegion) -> Result<Option<String>> {
1288        let our_lines: Vec<&str> = conflict.our_content.lines().collect();
1289        let their_lines: Vec<&str> = conflict.their_content.lines().collect();
1290
1291        // Check if one side is a subset of the other (pure addition)
1292        if our_lines.is_empty() {
1293            return Ok(Some(conflict.their_content.clone()));
1294        }
1295        if their_lines.is_empty() {
1296            return Ok(Some(conflict.our_content.clone()));
1297        }
1298
1299        // Try to merge additions intelligently
1300        let mut merged_lines = Vec::new();
1301        let mut our_idx = 0;
1302        let mut their_idx = 0;
1303
1304        while our_idx < our_lines.len() || their_idx < their_lines.len() {
1305            if our_idx >= our_lines.len() {
1306                // Only their lines left
1307                merged_lines.extend_from_slice(&their_lines[their_idx..]);
1308                break;
1309            } else if their_idx >= their_lines.len() {
1310                // Only our lines left
1311                merged_lines.extend_from_slice(&our_lines[our_idx..]);
1312                break;
1313            } else if our_lines[our_idx] == their_lines[their_idx] {
1314                // Same line - add once
1315                merged_lines.push(our_lines[our_idx]);
1316                our_idx += 1;
1317                their_idx += 1;
1318            } else {
1319                // Different lines - this might be too complex
1320                return Ok(None);
1321            }
1322        }
1323
1324        Ok(Some(merged_lines.join("\n")))
1325    }
1326
1327    /// Resolve import/dependency conflicts by sorting and merging
1328    fn resolve_import_conflict(
1329        &self,
1330        conflict: &ConflictRegion,
1331        file_path: &str,
1332    ) -> Result<Option<String>> {
1333        // Only apply to likely import sections in common file types
1334        let is_import_file = file_path.ends_with(".rs")
1335            || file_path.ends_with(".py")
1336            || file_path.ends_with(".js")
1337            || file_path.ends_with(".ts")
1338            || file_path.ends_with(".go")
1339            || file_path.ends_with(".java")
1340            || file_path.ends_with(".swift")
1341            || file_path.ends_with(".kt")
1342            || file_path.ends_with(".cs");
1343
1344        if !is_import_file {
1345            return Ok(None);
1346        }
1347
1348        let our_lines: Vec<&str> = conflict.our_content.lines().collect();
1349        let their_lines: Vec<&str> = conflict.their_content.lines().collect();
1350
1351        // Check if all lines look like imports/uses
1352        let our_imports = our_lines
1353            .iter()
1354            .all(|line| self.is_import_line(line, file_path));
1355        let their_imports = their_lines
1356            .iter()
1357            .all(|line| self.is_import_line(line, file_path));
1358
1359        if our_imports && their_imports {
1360            // Merge and sort imports
1361            let mut all_imports: Vec<&str> = our_lines.into_iter().chain(their_lines).collect();
1362            all_imports.sort();
1363            all_imports.dedup();
1364
1365            return Ok(Some(all_imports.join("\n")));
1366        }
1367
1368        Ok(None)
1369    }
1370
1371    /// Check if a line looks like an import statement
1372    fn is_import_line(&self, line: &str, file_path: &str) -> bool {
1373        let trimmed = line.trim();
1374
1375        if trimmed.is_empty() {
1376            return true; // Empty lines are OK in import sections
1377        }
1378
1379        if file_path.ends_with(".rs") {
1380            return trimmed.starts_with("use ") || trimmed.starts_with("extern crate");
1381        } else if file_path.ends_with(".py") {
1382            return trimmed.starts_with("import ") || trimmed.starts_with("from ");
1383        } else if file_path.ends_with(".js") || file_path.ends_with(".ts") {
1384            return trimmed.starts_with("import ")
1385                || trimmed.starts_with("const ")
1386                || trimmed.starts_with("require(");
1387        } else if file_path.ends_with(".go") {
1388            return trimmed.starts_with("import ") || trimmed == "import (" || trimmed == ")";
1389        } else if file_path.ends_with(".java") {
1390            return trimmed.starts_with("import ");
1391        } else if file_path.ends_with(".swift") {
1392            return trimmed.starts_with("import ") || trimmed.starts_with("@testable import ");
1393        } else if file_path.ends_with(".kt") {
1394            return trimmed.starts_with("import ") || trimmed.starts_with("@file:");
1395        } else if file_path.ends_with(".cs") {
1396            return trimmed.starts_with("using ") || trimmed.starts_with("extern alias ");
1397        }
1398
1399        false
1400    }
1401
1402    /// Normalize whitespace for comparison
1403    fn normalize_whitespace(&self, content: &str) -> String {
1404        content
1405            .lines()
1406            .map(|line| line.trim())
1407            .filter(|line| !line.is_empty())
1408            .collect::<Vec<_>>()
1409            .join("\n")
1410    }
1411
1412    /// Update a stack entry with new commit information
1413    /// NOTE: We keep the original branch name to preserve PR mapping, only update commit hash
1414    fn update_stack_entry(
1415        &mut self,
1416        stack_id: Uuid,
1417        entry_id: &Uuid,
1418        _new_branch: &str,
1419        new_commit_hash: &str,
1420    ) -> Result<()> {
1421        debug!(
1422            "Updating entry {} in stack {} with new commit {}",
1423            entry_id, stack_id, new_commit_hash
1424        );
1425
1426        // Get the stack and update the entry
1427        let stack = self
1428            .stack_manager
1429            .get_stack_mut(&stack_id)
1430            .ok_or_else(|| CascadeError::config(format!("Stack {stack_id} not found")))?;
1431
1432        // Find and update the entry
1433        if let Some(entry) = stack.entries.iter_mut().find(|e| e.id == *entry_id) {
1434            debug!(
1435                "Found entry {} - updating commit from '{}' to '{}' (keeping original branch '{}')",
1436                entry_id, entry.commit_hash, new_commit_hash, entry.branch
1437            );
1438
1439            // CRITICAL: Keep the original branch name to preserve PR mapping
1440            // Only update the commit hash to point to the new rebased commit
1441            entry.commit_hash = new_commit_hash.to_string();
1442
1443            // Note: Stack will be saved by the caller (StackManager) after rebase completes
1444
1445            debug!(
1446                "Successfully updated entry {} in stack {}",
1447                entry_id, stack_id
1448            );
1449            Ok(())
1450        } else {
1451            Err(CascadeError::config(format!(
1452                "Entry {entry_id} not found in stack {stack_id}"
1453            )))
1454        }
1455    }
1456
1457    /// Pull latest changes from remote
1458    fn pull_latest_changes(&self, branch: &str) -> Result<()> {
1459        info!("Pulling latest changes for branch {}", branch);
1460
1461        // First try to fetch (this might fail if no remote exists)
1462        match self.git_repo.fetch() {
1463            Ok(_) => {
1464                debug!("Fetch successful");
1465                // Now try to pull the specific branch
1466                match self.git_repo.pull(branch) {
1467                    Ok(_) => {
1468                        info!("Pull completed successfully for {}", branch);
1469                        Ok(())
1470                    }
1471                    Err(e) => {
1472                        warn!("Pull failed for {}: {}", branch, e);
1473                        // Don't fail the entire rebase for pull issues
1474                        Ok(())
1475                    }
1476                }
1477            }
1478            Err(e) => {
1479                warn!("Fetch failed: {}", e);
1480                // Don't fail if there's no remote configured
1481                Ok(())
1482            }
1483        }
1484    }
1485
1486    /// Check if rebase is in progress
1487    pub fn is_rebase_in_progress(&self) -> bool {
1488        // Check for git rebase state files
1489        let git_dir = self.git_repo.path().join(".git");
1490        git_dir.join("REBASE_HEAD").exists()
1491            || git_dir.join("rebase-merge").exists()
1492            || git_dir.join("rebase-apply").exists()
1493    }
1494
1495    /// Abort an in-progress rebase
1496    pub fn abort_rebase(&self) -> Result<()> {
1497        info!("Aborting rebase operation");
1498
1499        let git_dir = self.git_repo.path().join(".git");
1500
1501        // Clean up rebase state files
1502        if git_dir.join("REBASE_HEAD").exists() {
1503            std::fs::remove_file(git_dir.join("REBASE_HEAD")).map_err(|e| {
1504                CascadeError::Git(git2::Error::from_str(&format!(
1505                    "Failed to clean rebase state: {e}"
1506                )))
1507            })?;
1508        }
1509
1510        if git_dir.join("rebase-merge").exists() {
1511            std::fs::remove_dir_all(git_dir.join("rebase-merge")).map_err(|e| {
1512                CascadeError::Git(git2::Error::from_str(&format!(
1513                    "Failed to clean rebase-merge: {e}"
1514                )))
1515            })?;
1516        }
1517
1518        if git_dir.join("rebase-apply").exists() {
1519            std::fs::remove_dir_all(git_dir.join("rebase-apply")).map_err(|e| {
1520                CascadeError::Git(git2::Error::from_str(&format!(
1521                    "Failed to clean rebase-apply: {e}"
1522                )))
1523            })?;
1524        }
1525
1526        info!("Rebase aborted successfully");
1527        Ok(())
1528    }
1529
1530    /// Continue an in-progress rebase after conflict resolution
1531    pub fn continue_rebase(&self) -> Result<()> {
1532        info!("Continuing rebase operation");
1533
1534        // Check if there are still conflicts
1535        if self.git_repo.has_conflicts()? {
1536            return Err(CascadeError::branch(
1537                "Cannot continue rebase: there are unresolved conflicts. Resolve conflicts and stage files first.".to_string()
1538            ));
1539        }
1540
1541        // Stage resolved files
1542        self.git_repo.stage_conflict_resolved_files()?;
1543
1544        info!("Rebase continued successfully");
1545        Ok(())
1546    }
1547
1548    /// Check if there's an in-progress cherry-pick operation
1549    fn has_in_progress_cherry_pick(&self) -> Result<bool> {
1550        let git_dir = self.git_repo.path().join(".git");
1551        Ok(git_dir.join("CHERRY_PICK_HEAD").exists())
1552    }
1553
1554    /// Handle resuming an in-progress cherry-pick from a previous failed sync
1555    fn handle_in_progress_cherry_pick(&mut self, stack: &Stack) -> Result<RebaseResult> {
1556        use crate::cli::output::Output;
1557
1558        let git_dir = self.git_repo.path().join(".git");
1559
1560        Output::section("Resuming in-progress sync");
1561        println!();
1562        Output::info("Detected unfinished cherry-pick from previous sync");
1563        println!();
1564
1565        // Check if conflicts are resolved
1566        if self.git_repo.has_conflicts()? {
1567            let conflicted_files = self.git_repo.get_conflicted_files()?;
1568
1569            let result = RebaseResult {
1570                success: false,
1571                branch_mapping: HashMap::new(),
1572                conflicts: conflicted_files.clone(),
1573                new_commits: Vec::new(),
1574                error: Some(format!(
1575                    "Cannot continue: {} file(s) still have unresolved conflicts\n\n\
1576                    MANUAL CONFLICT RESOLUTION REQUIRED\n\
1577                    =====================================\n\n\
1578                    Conflicted files:\n{}\n\n\
1579                    Step 1: Analyze conflicts\n\
1580                    โ†’ Run: ca conflicts\n\
1581                    โ†’ Shows detailed conflict analysis\n\n\
1582                    Step 2: Resolve conflicts in your editor\n\
1583                    โ†’ Open conflicted files and edit them\n\
1584                    โ†’ Remove conflict markers (<<<<<<, ======, >>>>>>)\n\
1585                    โ†’ Keep the code you want\n\
1586                    โ†’ Save the files\n\n\
1587                    Step 3: Mark conflicts as resolved\n\
1588                    โ†’ Run: git add <resolved-files>\n\
1589                    โ†’ Or: git add -A (to stage all resolved files)\n\n\
1590                    Step 4: Complete the sync\n\
1591                    โ†’ Run: ca sync\n\
1592                    โ†’ Cascade will continue from where it left off\n\n\
1593                    Alternative: Abort and start over\n\
1594                    โ†’ Run: git cherry-pick --abort\n\
1595                    โ†’ Then: ca sync (starts fresh)",
1596                    conflicted_files.len(),
1597                    conflicted_files
1598                        .iter()
1599                        .map(|f| format!("  - {}", f))
1600                        .collect::<Vec<_>>()
1601                        .join("\n")
1602                )),
1603                summary: "Sync paused - conflicts need resolution".to_string(),
1604            };
1605
1606            return Ok(result);
1607        }
1608
1609        // Conflicts are resolved - continue the cherry-pick
1610        Output::info("Conflicts resolved, continuing cherry-pick...");
1611
1612        // Stage all resolved files
1613        self.git_repo.stage_conflict_resolved_files()?;
1614
1615        // Complete the cherry-pick by committing
1616        let cherry_pick_msg_file = git_dir.join("CHERRY_PICK_MSG");
1617        let commit_message = if cherry_pick_msg_file.exists() {
1618            std::fs::read_to_string(&cherry_pick_msg_file)
1619                .unwrap_or_else(|_| "Resolved conflicts".to_string())
1620        } else {
1621            "Resolved conflicts".to_string()
1622        };
1623
1624        match self.git_repo.commit(&commit_message) {
1625            Ok(_new_commit_id) => {
1626                Output::success("Cherry-pick completed");
1627
1628                // Clean up cherry-pick state
1629                if git_dir.join("CHERRY_PICK_HEAD").exists() {
1630                    let _ = std::fs::remove_file(git_dir.join("CHERRY_PICK_HEAD"));
1631                }
1632                if cherry_pick_msg_file.exists() {
1633                    let _ = std::fs::remove_file(&cherry_pick_msg_file);
1634                }
1635
1636                println!();
1637                Output::info("Continuing with rest of stack...");
1638                println!();
1639
1640                // Now continue with the rest of the rebase
1641                // We need to restart the full rebase since we don't track which entry we were on
1642                self.rebase_with_force_push(stack)
1643            }
1644            Err(e) => {
1645                let result = RebaseResult {
1646                    success: false,
1647                    branch_mapping: HashMap::new(),
1648                    conflicts: Vec::new(),
1649                    new_commits: Vec::new(),
1650                    error: Some(format!(
1651                        "Failed to complete cherry-pick: {}\n\n\
1652                        This usually means:\n\
1653                        - Git index is locked (another process accessing repo)\n\
1654                        - File permissions issue\n\
1655                        - Disk space issue\n\n\
1656                        Recovery:\n\
1657                        1. Check if another Git operation is running\n\
1658                        2. Run 'rm -f .git/index.lock' if stale lock exists\n\
1659                        3. Run 'git status' to check repo state\n\
1660                        4. Retry 'ca sync' after fixing the issue\n\n\
1661                        Or abort and start fresh:\n\
1662                        โ†’ Run: git cherry-pick --abort\n\
1663                        โ†’ Then: ca sync",
1664                        e
1665                    )),
1666                    summary: "Failed to complete cherry-pick".to_string(),
1667                };
1668
1669                Ok(result)
1670            }
1671        }
1672    }
1673}
1674
1675impl RebaseResult {
1676    /// Get a summary of the rebase operation
1677    pub fn get_summary(&self) -> String {
1678        if self.success {
1679            format!("โœ… {}", self.summary)
1680        } else {
1681            format!(
1682                "โŒ Rebase failed: {}",
1683                self.error.as_deref().unwrap_or("Unknown error")
1684            )
1685        }
1686    }
1687
1688    /// Check if any conflicts occurred
1689    pub fn has_conflicts(&self) -> bool {
1690        !self.conflicts.is_empty()
1691    }
1692
1693    /// Get the number of successful operations
1694    pub fn success_count(&self) -> usize {
1695        self.new_commits.len()
1696    }
1697}
1698
1699#[cfg(test)]
1700mod tests {
1701    use super::*;
1702    use std::path::PathBuf;
1703    use std::process::Command;
1704    use tempfile::TempDir;
1705
1706    #[allow(dead_code)]
1707    fn create_test_repo() -> (TempDir, PathBuf) {
1708        let temp_dir = TempDir::new().unwrap();
1709        let repo_path = temp_dir.path().to_path_buf();
1710
1711        // Initialize git repository
1712        Command::new("git")
1713            .args(["init"])
1714            .current_dir(&repo_path)
1715            .output()
1716            .unwrap();
1717        Command::new("git")
1718            .args(["config", "user.name", "Test"])
1719            .current_dir(&repo_path)
1720            .output()
1721            .unwrap();
1722        Command::new("git")
1723            .args(["config", "user.email", "test@test.com"])
1724            .current_dir(&repo_path)
1725            .output()
1726            .unwrap();
1727
1728        // Create initial commit
1729        std::fs::write(repo_path.join("README.md"), "# Test").unwrap();
1730        Command::new("git")
1731            .args(["add", "."])
1732            .current_dir(&repo_path)
1733            .output()
1734            .unwrap();
1735        Command::new("git")
1736            .args(["commit", "-m", "Initial"])
1737            .current_dir(&repo_path)
1738            .output()
1739            .unwrap();
1740
1741        (temp_dir, repo_path)
1742    }
1743
1744    #[test]
1745    fn test_conflict_region_creation() {
1746        let region = ConflictRegion {
1747            start: 0,
1748            end: 50,
1749            start_line: 1,
1750            end_line: 3,
1751            our_content: "function test() {\n    return true;\n}".to_string(),
1752            their_content: "function test() {\n  return true;\n}".to_string(),
1753        };
1754
1755        assert_eq!(region.start_line, 1);
1756        assert_eq!(region.end_line, 3);
1757        assert!(region.our_content.contains("return true"));
1758        assert!(region.their_content.contains("return true"));
1759    }
1760
1761    #[test]
1762    fn test_rebase_strategies() {
1763        assert_eq!(RebaseStrategy::ForcePush, RebaseStrategy::ForcePush);
1764        assert_eq!(RebaseStrategy::Interactive, RebaseStrategy::Interactive);
1765    }
1766
1767    #[test]
1768    fn test_rebase_options() {
1769        let options = RebaseOptions::default();
1770        assert_eq!(options.strategy, RebaseStrategy::ForcePush);
1771        assert!(!options.interactive);
1772        assert!(options.auto_resolve);
1773        assert_eq!(options.max_retries, 3);
1774    }
1775
1776    #[test]
1777    fn test_cleanup_guard_tracks_branches() {
1778        let mut guard = TempBranchCleanupGuard::new();
1779        assert!(guard.branches.is_empty());
1780
1781        guard.add_branch("test-branch-1".to_string());
1782        guard.add_branch("test-branch-2".to_string());
1783
1784        assert_eq!(guard.branches.len(), 2);
1785        assert_eq!(guard.branches[0], "test-branch-1");
1786        assert_eq!(guard.branches[1], "test-branch-2");
1787    }
1788
1789    #[test]
1790    fn test_cleanup_guard_prevents_double_cleanup() {
1791        use std::process::Command;
1792        use tempfile::TempDir;
1793
1794        // Create a temporary git repo
1795        let temp_dir = TempDir::new().unwrap();
1796        let repo_path = temp_dir.path();
1797
1798        Command::new("git")
1799            .args(["init"])
1800            .current_dir(repo_path)
1801            .output()
1802            .unwrap();
1803
1804        Command::new("git")
1805            .args(["config", "user.name", "Test"])
1806            .current_dir(repo_path)
1807            .output()
1808            .unwrap();
1809
1810        Command::new("git")
1811            .args(["config", "user.email", "test@test.com"])
1812            .current_dir(repo_path)
1813            .output()
1814            .unwrap();
1815
1816        // Create initial commit
1817        std::fs::write(repo_path.join("test.txt"), "test").unwrap();
1818        Command::new("git")
1819            .args(["add", "."])
1820            .current_dir(repo_path)
1821            .output()
1822            .unwrap();
1823        Command::new("git")
1824            .args(["commit", "-m", "initial"])
1825            .current_dir(repo_path)
1826            .output()
1827            .unwrap();
1828
1829        let git_repo = GitRepository::open(repo_path).unwrap();
1830
1831        // Create a test branch
1832        git_repo.create_branch("test-temp", None).unwrap();
1833
1834        let mut guard = TempBranchCleanupGuard::new();
1835        guard.add_branch("test-temp".to_string());
1836
1837        // First cleanup should work
1838        guard.cleanup(&git_repo);
1839        assert!(guard.cleaned);
1840
1841        // Second cleanup should be a no-op (shouldn't panic)
1842        guard.cleanup(&git_repo);
1843        assert!(guard.cleaned);
1844    }
1845
1846    #[test]
1847    fn test_rebase_result() {
1848        let result = RebaseResult {
1849            success: true,
1850            branch_mapping: std::collections::HashMap::new(),
1851            conflicts: vec!["abc123".to_string()],
1852            new_commits: vec!["def456".to_string()],
1853            error: None,
1854            summary: "Test summary".to_string(),
1855        };
1856
1857        assert!(result.success);
1858        assert!(result.has_conflicts());
1859        assert_eq!(result.success_count(), 1);
1860    }
1861
1862    #[test]
1863    fn test_import_line_detection() {
1864        let (_temp_dir, repo_path) = create_test_repo();
1865        let git_repo = crate::git::GitRepository::open(&repo_path).unwrap();
1866        let stack_manager = crate::stack::StackManager::new(&repo_path).unwrap();
1867        let options = RebaseOptions::default();
1868        let rebase_manager = RebaseManager::new(stack_manager, git_repo, options);
1869
1870        // Test Swift import detection
1871        assert!(rebase_manager.is_import_line("import Foundation", "test.swift"));
1872        assert!(rebase_manager.is_import_line("@testable import MyModule", "test.swift"));
1873        assert!(!rebase_manager.is_import_line("class MyClass {", "test.swift"));
1874
1875        // Test Kotlin import detection
1876        assert!(rebase_manager.is_import_line("import kotlin.collections.*", "test.kt"));
1877        assert!(rebase_manager.is_import_line("@file:JvmName(\"Utils\")", "test.kt"));
1878        assert!(!rebase_manager.is_import_line("fun myFunction() {", "test.kt"));
1879
1880        // Test C# import detection
1881        assert!(rebase_manager.is_import_line("using System;", "test.cs"));
1882        assert!(rebase_manager.is_import_line("using System.Collections.Generic;", "test.cs"));
1883        assert!(rebase_manager.is_import_line("extern alias GridV1;", "test.cs"));
1884        assert!(!rebase_manager.is_import_line("namespace MyNamespace {", "test.cs"));
1885
1886        // Test empty lines are allowed in import sections
1887        assert!(rebase_manager.is_import_line("", "test.swift"));
1888        assert!(rebase_manager.is_import_line("   ", "test.kt"));
1889        assert!(rebase_manager.is_import_line("", "test.cs"));
1890    }
1891}