gh auth status || { echo "Error: Run 'gh auth login' first"; exit 1; }

# Check for clean working tree (optional - can skip if user wants)
if ! git diff --quiet HEAD 2>/dev/null; then
    echo "Warning: Uncommitted changes detected."
    echo "Consider committing or stashing before starting new work."
fi

# Validate inputs before shell use
validate_branch() {
    [[ "$1" =~ ^[a-zA-Z0-9/_-]+$ ]] || { echo "Invalid branch name: $1"; exit 1; }
}

validate_number() {
    [[ "$1" =~ ^[0-9]+$ ]] || { echo "Invalid number: $1"; exit 1; }
}

validate_slug() {
    [[ "$1" =~ ^[a-z0-9-]+$ ]] || { echo "Invalid slug: $1"; exit 1; }
}

# Create label if it doesn't exist
ensure_label() {
    local label="$1"
    local color="${2:-ededed}"
    gh label list --search "$label" --json name --jq '.[].name' 2>/dev/null | grep -qx "$label" || \
        gh label create "$label" --color "$color" 2>/dev/null || true
}

# Ensure required labels exist
ensure_label "in-progress" "FBCA04"
ensure_label "claude-code" "7C3AED"

BRANCH=$(git branch --show-current)
ISSUE=$(echo "$BRANCH" | grep -oE 'feat/([0-9]+)' | grep -oE '[0-9]+' || echo "")

# If no issue from branch, check for planned issues
if [ -z "$ISSUE" ]; then
    ISSUE=$(gh issue list --label planned --limit 1 --json number --jq '.[0].number' 2>/dev/null)
fi

if [ -z "$ISSUE" ]; then
    echo "No planned issue found."
    echo "Provide issue number or run /gw-plan first."
    exit 1
fi

validate_number "$ISSUE"

# Verify issue exists
if ! gh issue view "$ISSUE" &>/dev/null; then
    echo "Issue #$ISSUE not found on GitHub"
    exit 1
fi

ISSUE_TITLE=$(gh issue view "$ISSUE" --json title --jq '.title')
echo "Working on: $ISSUE_TITLE"

# Generate branch name from issue
CLEAN_TITLE=$(echo "$ISSUE_TITLE" | sed 's/^brainstorm: //' | sed 's/^feat: //')
SLUG=$(echo "$CLEAN_TITLE" | tr '[:upper:]' '[:lower:]' | sed 's/[^a-z0-9]/-/g' | sed 's/--*/-/g' | sed 's/^-//' | sed 's/-$//' | cut -c1-30)
EXPECTED_BRANCH="feat/${ISSUE}-${SLUG}"

# Validate branch name before git operations
validate_branch "$EXPECTED_BRANCH"

# Check if already on correct branch
if [ "$BRANCH" = "$EXPECTED_BRANCH" ]; then
    echo "Already on branch: $BRANCH"
elif [ "$BRANCH" = "main" ] || [ "$BRANCH" = "master" ]; then
    # Create new branch from main
    git checkout -b "$EXPECTED_BRANCH" || {
        echo "Error: Failed to create branch."
        exit 1
    }
    echo "Created branch: $EXPECTED_BRANCH"
else
    echo "Currently on: $BRANCH"
    echo "Expected: $EXPECTED_BRANCH"
    echo "Continue on current branch or switch?"
fi

# Stage changes (be specific, don't use -A blindly)
git add <relevant-files>

# Commit with conventional message
git commit -m "feat: implement #${ISSUE}

Implements the feature as specified in the plan.

Closes #${ISSUE}"

git push -u origin "$BRANCH" || {
    echo "Error: Failed to push. Check remote access."
    exit 1
}

# Get clean title for PR
PR_TITLE="feat: $(echo "$ISSUE_TITLE" | sed 's/^brainstorm: //' | sed 's/^feat: //')"

PR_URL=$(gh pr create \
    --title "$PR_TITLE" \
    --label "claude-code" \
    --body "Closes #${ISSUE}

## Summary

[Describe what was implemented]

## Changes

- [List key changes]

## Testing

- [ ] Tests pass locally
- [ ] Manual verification completed

## Checklist

- [ ] Code follows project conventions
- [ ] Tests added for new functionality
- [ ] Documentation updated if needed" \
    --head "$BRANCH") || {
    echo "Error: Failed to create PR. Check: gh auth status"
    exit 1
}

# Extract PR number
PR_NUM=$(echo "$PR_URL" | grep -oE '/pull/[0-9]+' | grep -oE '[0-9]+')
validate_number "$PR_NUM"

echo "Created PR #${PR_NUM}: $PR_URL"

# Add in-progress label to issue
gh issue edit "$ISSUE" --add-label "in-progress" --add-label "claude-code" 2>/dev/null || true

# Remove planned label
gh issue edit "$ISSUE" --remove-label "planned" 2>/dev/null || true

Implementation complete!

PR: #{PR_NUM}
URL: {PR_URL}
Issue: #{ISSUE}
Branch: {BRANCH}

Labels: in-progress, claude-code

Next step: Wait for review, then run /gw-review