---
diff_output: '' # set at runtime
spec_file: '' # set at runtime (path or empty)
review_mode: '' # set at runtime: "full" or "no-spec"
story_key: '' # set at runtime when discovered from sprint status
---

# Step 1: Gather Context

## RULES

- YOU MUST ALWAYS SPEAK OUTPUT in your Agent communication style with the config `{communication_language}`, tailored to `{game_dev_experience}`
- The prompt that triggered this workflow IS the intent — not a hint.
- Do not modify any files. This step is read-only.

## INSTRUCTIONS

1. **Find the review target.** The conversation context before this skill was triggered IS your starting point — not a blank slate. Check in this order — stop as soon as the review target is identified:

   **Tier 1 — Explicit argument.**
   Did the user pass a PR, commit SHA, branch, spec file, or diff source this message?
   - PR reference → resolve to branch/commit via `gh pr view`. If resolution fails, ask for a SHA or branch.
   - Commit or branch → use directly.
   - Spec file → set `{spec_file}` to the provided path. Check its frontmatter for `baseline_commit`. If found, use as diff baseline. If not found, continue the cascade (a spec alone does not identify a diff source).
   - Also scan the argument for diff-mode keywords that narrow the scope:
     - "staged" / "staged changes" → Staged changes only
     - "uncommitted" / "working tree" / "all changes" → Uncommitted changes (staged + unstaged)
     - "branch diff" / "vs main" / "against main" / "compared to <branch>" → Branch diff (extract base branch if mentioned)
     - "commit range" / "last N commits" / "<from-sha>..<to-sha>" → Specific commit range
     - "this diff" / "provided diff" / "paste" → User-provided diff (do not match bare "diff" — it appears in other modes)
   - When multiple keywords match, prefer the most specific (e.g., "branch diff" over bare "diff").

   **Tier 2 — Recent conversation.**
   Do the last few messages reveal what the user wants to be reviewed? Look for spec paths, commit refs, branches, PRs, or descriptions of a change. Apply the same diff-mode keyword scan and routing as Tier 1.

   **Tier 3 — Sprint tracking.**
   Look for a sprint status file (`*sprint-status*`) in `{implementation_artifacts}` or `{planning_artifacts}`. If found, scan for stories with status `review`:
   - **Exactly one `review` story:** Set `{story_key}` to the story's key (e.g., `1-2-user-auth`). Suggest it: "I found story <story-id> in `review` status. Would you like to review its changes? [Y] Yes / [N] No, let me choose". If confirmed, use the story context to determine the diff source (branch name derived from story slug, or uncommitted changes). If declined, clear `{story_key}` and fall through.
   - **Multiple `review` stories:** Present them as numbered options alongside a manual choice option. Wait for user selection. If a story is selected, set `{story_key}` and use its context to determine the diff source. If manual choice is selected, clear `{story_key}` and fall through.
   - **None:** Fall through.

   **Tier 4 — Current git state.**
   If version control is unavailable, skip to Tier 5. Otherwise, check the current branch and HEAD. If the branch is not `main` (or the default branch), confirm: "I see HEAD is `<short-sha>` on `<branch>` — do you want to review this branch's changes?" If confirmed, treat as a branch diff against `main`. If declined, fall through.

   **Tier 5 — Ask.**
   Fall through to instruction 2.

   Never ask extra questions beyond what the cascade prescribes. If a tier above already identified the target, skip the remaining tiers and proceed to instruction 3 (construct diff).

2. HALT. Ask the user: **What do you want to review?** Present these options:
   - **Uncommitted changes** (staged + unstaged)
   - **Staged changes only**
   - **Branch diff** vs a base branch (ask which base branch)
   - **Specific commit range** (ask for the range)
   - **Provided diff or file list** (user pastes or provides a path)

3. Construct `{diff_output}` from the chosen source.
   - For **staged changes only**: run `git diff --cached`.
   - For **uncommitted changes** (staged + unstaged): run `git diff HEAD`.
   - For **branch diff**: verify the base branch exists before running `git diff`. If it does not exist, HALT and ask the user for a valid branch.
   - For **commit range**: verify the range resolves. If it does not, HALT and ask the user for a valid range.
   - For **provided diff**: validate the content is non-empty and parseable as a unified diff. If it is not parseable, HALT and ask the user to provide a valid diff.
   - For **file list**: validate each path exists in the working tree. Construct `{diff_output}` by running `git diff HEAD -- <path1> <path2> ...`. If any paths are untracked (new files not yet staged), use `git diff --no-index /dev/null <path>` to include them. If the diff is empty (files have no uncommitted changes and are not untracked), ask the user whether to review the full file contents or to specify a different baseline.
   - After constructing `{diff_output}`, verify it is non-empty regardless of source type. If empty, HALT and tell the user there is nothing to review.

4. **Set the spec context.**
   - If `{spec_file}` is already set (from Tier 1 or Tier 2): verify the file exists and is readable, then set `{review_mode}` = `"full"`.
   - Otherwise, ask the user: **Is there a spec or story file that provides context for these changes?**
     - If yes: set `{spec_file}` to the path provided, verify the file exists and is readable, then set `{review_mode}` = `"full"`.
     - If no: set `{review_mode}` = `"no-spec"`.

5. If `{review_mode}` = `"full"` and the file at `{spec_file}` has a `context` field in its frontmatter listing additional docs, load each referenced document. Warn the user about any docs that cannot be found.

6. Sanity check: if `{diff_output}` exceeds approximately 3000 lines, warn the user and offer to chunk the review by file group.
   - If the user opts to chunk: agree on the first group, narrow `{diff_output}` accordingly, and list the remaining groups for the user to note for follow-up runs.
   - If the user declines: proceed as-is with the full diff.

### CHECKPOINT

Present a summary before proceeding: diff stats (files changed, lines added/removed), `{review_mode}`, and loaded spec/context docs (if any). HALT and wait for user confirmation to proceed.


## NEXT

Read fully and follow `./step-02-review.md`
