# Install GitHub CLI (if not installed)
# macOS: brew install gh
# Linux: See https://cli.github.com/

# Authenticate
gh auth login

# Parse arguments
SCOPE=""
DRAFT_FLAG=""
BASE_BRANCH="main"

# Example parsing:
# "root --draft" → SCOPE="root", DRAFT_FLAG="--draft", BASE_BRANCH="main"
# "--base staging" → SCOPE="", DRAFT_FLAG="", BASE_BRANCH="staging"
# "my-service --draft --base develop" → SCOPE="my-service", DRAFT_FLAG="--draft", BASE_BRANCH="develop"

# Find monorepo root (handles submodules)
if SUPERPROJECT=$(git rev-parse --show-superproject-working-tree 2>/dev/null) && [ -n "$SUPERPROJECT" ]; then
    # We're in a submodule
    MONOREPO_ROOT="$SUPERPROJECT"
else
    # We're in root or standalone repo
    MONOREPO_ROOT=$(git rev-parse --show-toplevel)
fi

# Get current working directory
CURRENT_DIR=$(pwd)

# Determine repository context
if [ -n "$SCOPE" ]; then
    # User specified scope
    if [ "$SCOPE" = "root" ]; then
        REPO_PATH="$MONOREPO_ROOT"
    else
        REPO_PATH="$MONOREPO_ROOT/$SCOPE"
    fi
else
    # Auto-detect from current directory
    # If in submodule, use submodule path
    # If in root, use root path
    if [[ "$CURRENT_DIR" == "$MONOREPO_ROOT" ]]; then
        REPO_PATH="$MONOREPO_ROOT"
    else
        # Find which submodule we're in
        REPO_PATH=$(git -C "$CURRENT_DIR" rev-parse --show-toplevel)
    fi
fi

# Validate repository
if [ ! -d "$REPO_PATH/.git" ]; then
    echo "❌ Error: Not a valid git repository: $REPO_PATH" >&2
    exit 1
fi

# Change to repository directory
cd "$REPO_PATH"

# Get current branch
CURRENT_BRANCH=$(git rev-parse --abbrev-ref HEAD)

# Check if on protected branch
if [ "$CURRENT_BRANCH" = "main" ] || [ "$CURRENT_BRANCH" = "master" ]; then
    echo "❌ Cannot create PR from protected branch: $CURRENT_BRANCH" >&2
    echo "" >&2
    echo "Please create a feature branch first:" >&2
    echo "  git checkout -b feature/your-feature-name" >&2
    echo "" >&2
    exit 1
fi

# Check for uncommitted changes
UNCOMMITTED=$(git status --porcelain)
if [ -n "$UNCOMMITTED" ]; then
    echo "❌ Error: You have uncommitted changes" >&2
    echo "" >&2
    echo "Please commit or stash your changes before creating a PR:" >&2
    git status --short
    echo "" >&2
    exit 1
fi

# Check if branch has commits ahead of base
COMMITS_AHEAD=$(git rev-list --count "$BASE_BRANCH..HEAD" 2>/dev/null || echo "0")
if [ "$COMMITS_AHEAD" = "0" ]; then
    echo "❌ Error: No commits to create PR from" >&2
    echo "Current branch '$CURRENT_BRANCH' has no commits ahead of '$BASE_BRANCH'" >&2
    exit 1
fi

echo "ℹ️  Branch: $CURRENT_BRANCH ($COMMITS_AHEAD commits ahead of $BASE_BRANCH)"

# Check if branch exists on remote
REMOTE_BRANCH=$(git ls-remote --heads origin "$CURRENT_BRANCH" 2>/dev/null)

if [ -z "$REMOTE_BRANCH" ]; then
    echo "ℹ️  Branch not on remote, pushing..."
    git push -u origin "$CURRENT_BRANCH" || {
        echo "❌ Failed to push branch to remote" >&2
        exit 1
    }
    echo "✅ Branch pushed to origin/$CURRENT_BRANCH"
else
    # Check if local is behind remote
    LOCAL_HASH=$(git rev-parse HEAD)
    REMOTE_HASH=$(git rev-parse "origin/$CURRENT_BRANCH" 2>/dev/null || echo "")

    if [ "$LOCAL_HASH" != "$REMOTE_HASH" ]; then
        echo "ℹ️  Local branch differs from remote, pushing..."
        git push origin "$CURRENT_BRANCH" || {
            echo "❌ Failed to push branch to remote" >&2
            exit 1
        }
        echo "✅ Branch updated on remote"
    else
        echo "ℹ️  Branch already up to date on remote"
    fi
fi

# Check for existing PR using GitHub CLI
EXISTING_PR=$(gh pr view "$CURRENT_BRANCH" --json number,title,url 2>/dev/null || echo "")

if [ -n "$EXISTING_PR" ]; then
    # PR exists - extract info
    PR_NUMBER=$(echo "$EXISTING_PR" | jq -r '.number')
    PR_TITLE=$(echo "$EXISTING_PR" | jq -r '.title')
    PR_URL=$(echo "$EXISTING_PR" | jq -r '.url')

    echo ""
    echo "ℹ️  Existing PR found:"
    echo "  #$PR_NUMBER: $PR_TITLE"
    echo "  $PR_URL"
    echo ""

    # Use AskUserQuestion to ask user what to do
    # Options:
    # 1. Update PR (regenerate title/body and update)
    # 2. View PR in browser (open URL)
    # 3. Cancel (do nothing)

    # If user chooses "Update PR":
    # - Generate new title and body (Steps 6-7)
    # - Update PR using: gh pr edit "$PR_NUMBER" --title "..." --body "..."
    # - Show success message

    # If user chooses "View PR":
    # - Open PR URL in browser: gh pr view --web

    # If user chooses "Cancel":
    # - Exit gracefully
fi

# Get all commits from base branch to current branch
COMMITS=$(git log "$BASE_BRANCH..HEAD" --oneline)
COMMIT_COUNT=$(echo "$COMMITS" | wc -l | tr -d ' ')

echo "ℹ️  Analyzing $COMMIT_COUNT commits..."

# Get the first commit message (most recent)
LATEST_COMMIT=$(git log -1 --pretty=%B)

# Detect commit type from latest commit or analyze all commits
# Try to extract type from conventional commit format
if echo "$LATEST_COMMIT" | grep -qE '^(feat|fix|docs|refactor|test|chore|perf|ci|build):'; then
    # Extract type and description from conventional commit
    COMMIT_TYPE=$(echo "$LATEST_COMMIT" | grep -oE '^[a-z]+' | head -1)
    COMMIT_DESC=$(echo "$LATEST_COMMIT" | sed -E 's/^[a-z]+(\([^)]+\))?:\s*//')
else
    # Analyze changes to determine type
    ALL_COMMITS=$(git log "$BASE_BRANCH..HEAD" --pretty=%B)

    if echo "$ALL_COMMITS" | grep -qi "fix\|bug"; then
        COMMIT_TYPE="fix"
    elif echo "$ALL_COMMITS" | grep -qi "feat\|feature\|add"; then
        COMMIT_TYPE="feat"
    elif echo "$ALL_COMMITS" | grep -qi "docs\|documentation"; then
        COMMIT_TYPE="docs"
    elif echo "$ALL_COMMITS" | grep -qi "refactor"; then
        COMMIT_TYPE="refactor"
    elif echo "$ALL_COMMITS" | grep -qi "test"; then
        COMMIT_TYPE="test"
    else
        COMMIT_TYPE="feat"
    fi

    # Generate description from branch name or commit
    COMMIT_DESC=$(echo "$LATEST_COMMIT" | head -1 | sed 's/^\s*//')
fi

# Generate PR title (capitalize first letter)
PR_TITLE="$COMMIT_TYPE: $COMMIT_DESC"

echo "ℹ️  Generated PR title: $PR_TITLE"

# Generate PR body with summary from commits
PR_BODY="## Summary

"

# Add commit summaries
if [ "$COMMIT_COUNT" -eq 1 ]; then
    # Single commit - use full message
    PR_BODY+="$LATEST_COMMIT

"
else
    # Multiple commits - list them
    PR_BODY+="This PR includes $COMMIT_COUNT commits:

"
    while IFS= read -r commit; do
        PR_BODY+="- $commit
"
    done <<< "$COMMITS"
    PR_BODY+="
"
fi

# Add test plan section
PR_BODY+="## Test Plan

- [ ] Code builds successfully
- [ ] Tests pass
- [ ] Manual testing completed
- [ ] Documentation updated (if needed)

## Changes

"

# List changed files
CHANGED_FILES=$(git diff --name-only "$BASE_BRANCH..HEAD")
while IFS= read -r file; do
    PR_BODY+="- \`$file\`
"
done <<< "$CHANGED_FILES"

echo ""
echo "Generated PR description:"
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
echo "$PR_BODY"
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
echo ""

# IMPORTANT: No Claude Code attribution in PR content

# Build gh pr create command
GH_CMD="gh pr create --title \"$PR_TITLE\" --body \"$PR_BODY\" --base \"$BASE_BRANCH\""

# Add draft flag if specified
if [ "$DRAFT_FLAG" = "--draft" ]; then
    GH_CMD+=" --draft"
fi

# Execute PR creation
eval "$GH_CMD" || {
    echo "❌ Failed to create PR" >&2
    exit 1
}

# Get PR URL
PR_URL=$(gh pr view --json url -q '.url')

echo ""
echo "✅ Pull Request created successfully!"
echo ""
echo "PR URL: $PR_URL"
echo ""
echo "Next steps:"
echo "  - Review PR in browser: gh pr view --web"
echo "  - Check CI status: gh pr checks"
echo "  - Request reviews: gh pr ready (if draft)"
echo ""

# Update PR title and body
gh pr edit "$PR_NUMBER" --title "$PR_TITLE" --body "$PR_BODY" || {
    echo "❌ Failed to update PR" >&2
    exit 1
}

echo "✅ Pull Request #$PR_NUMBER updated successfully!"
echo "PR URL: $PR_URL"

# Check for existing PR
gh pr view <branch> --json number,title,url

# Create new PR
gh pr create --title "..." --body "..." --base <branch> [--draft]

# Update existing PR
gh pr edit <number> --title "..." --body "..."

# View PR in browser
gh pr view --web

# Check PR status
gh pr checks