#!/bin/bash

# Reset git repositories to their default branch (main or master) and drop all local changes
# Usage: git-reset [dir1] [dir2] ...
# If no arguments provided, uses current working directory

# Check if gum is installed
if ! command -v gum &>/dev/null; then
    echo "Error: gum is not installed. Install it with: brew install gum"
    exit 1
fi

# Array of directories - from arguments or current directory
if [[ $# -gt 0 ]]; then
    directories=("$@")
else
    directories=("$(pwd)")
fi

# Function to determine default branch
get_default_branch() {
    local dir="$1"
    cd "$dir" || return 1

    # Try to get the default branch from remote
    local default_branch=$(git symbolic-ref refs/remotes/origin/HEAD 2>/dev/null | sed 's@^refs/remotes/origin/@@')

    # If that fails, check if main exists, otherwise use master
    if [[ -z "$default_branch" ]]; then
        if git show-ref --verify --quiet refs/remotes/origin/main; then
            default_branch="main"
        elif git show-ref --verify --quiet refs/remotes/origin/master; then
            default_branch="master"
        else
            # Try to find any branch that might be the default
            default_branch=$(git branch -r | grep -E 'origin/(main|master)' | head -1 | sed 's@.*origin/@@' | xargs)
            if [[ -z "$default_branch" ]]; then
                default_branch="main" # fallback
            fi
        fi
    fi

    echo "$default_branch"
}

# Function to check if repo has local changes
has_local_changes() {
    # Check for uncommitted changes (staged, unstaged, or untracked)
    if ! git diff --quiet HEAD 2>/dev/null ||
        ! git diff --cached --quiet 2>/dev/null ||
        [[ -n $(git ls-files --others --exclude-standard 2>/dev/null) ]]; then
        return 0
    fi
    return 1
}

# Function to reset a single git repository
reset_repo() {
    local dir="$1"

    # Change to directory
    cd "$dir" || {
        echo "  ❌ Failed to change to directory: $dir"
        return 1
    }

    # Get the default branch
    default_branch=$(get_default_branch "$dir")

    # Check for local changes and ask for confirmation
    if has_local_changes; then
        echo ""
        gum style --foreground 220 "⚠️  $dir has local changes:"
        git status --short | head -10
        local total_changes=$(git status --short | wc -l | tr -d ' ')
        if [[ $total_changes -gt 10 ]]; then
            echo "  ... and $((total_changes - 10)) more"
        fi
        echo ""
        if ! gum confirm "Drop local changes and reset to origin/$default_branch?" </dev/tty; then
            echo "  ⏭️  $dir → skipped"
            return 0
        fi
    fi

    # Fetch latest changes and check for repository errors
    fetch_output=$(git fetch origin 2>&1)
    fetch_exit_code=$?

    if [ $fetch_exit_code -ne 0 ]; then
        if echo "$fetch_output" | grep -q "Repository not found\|Could not read from remote repository"; then
            echo "  🗑️  $dir → remote not found, deleted"
            cd ..
            rm -rf "$dir"
            return 1
        else
            echo "  ❌ $dir → fetch failed"
            return 1
        fi
    fi

    # Reset any uncommitted changes
    git reset --hard HEAD &>/dev/null
    git clean -fd &>/dev/null

    # Switch to default branch (force checkout to ignore local changes)
    if ! git checkout -f "$default_branch" &>/dev/null; then
        echo "  ❌ $dir → checkout $default_branch failed"
        return 1
    fi

    # Reset to upstream branch, dropping all local changes
    if git reset --hard "origin/$default_branch" &>/dev/null; then
        echo "  ✅ $dir → reset & pulled $default_branch"
    else
        echo "  ❌ $dir → reset to $default_branch failed"
        return 1
    fi
}

# Loop through each directory
for dir in "${directories[@]}"; do
    # Check if directory exists
    if [[ ! -d "$dir" ]]; then
        echo "❌ $dir → directory does not exist"
        continue
    fi

    # Check if it's a git repository
    if [[ -d "$dir/.git" ]]; then
        reset_repo "$dir"
    else
        # Not a git repo, search subdirectories
        echo "📁 $dir → scanning for git repos..."
        found_repos=0
        while IFS= read -r -d '' subdir; do
            repo_dir="$(dirname "$subdir")"
            reset_repo "$repo_dir"
            ((found_repos++))
        done < <(find "$dir" -maxdepth 2 -type d -name ".git" -print0)

        if [[ $found_repos -eq 0 ]]; then
            echo "  ❌ no git repositories found"
        else
            echo "  📊 processed $found_repos repo(s)"
        fi
    fi
done