use std::path::Path;
use anyhow::{Result, Context};
use git2::Repository;
use colored::*;
use std::fs;

const FTC_SDK_URL: &str = "https://github.com/FIRST-Tech-Challenge/FtcRobotController.git";
const FTC_SDK_VERSION: &str = "v10.1.1";

pub fn install(sdk_path: &Path, android_sdk_path: &Path) -> Result<()> {
    if sdk_path.exists() {
        println!("{} FTC SDK already installed at: {}", 
            "✓".green(), 
            sdk_path.display()
        );
        // Make sure local.properties exists even if SDK was already installed
        create_local_properties(sdk_path, android_sdk_path)?;
        return check_version(sdk_path);
    }
    
    println!("{}", "Installing FTC SDK...".bright_yellow());
    println!("Cloning from: {}", FTC_SDK_URL);
    println!("Version: {}", FTC_SDK_VERSION);
    
    // Clone the repository
    let repo = Repository::clone(FTC_SDK_URL, sdk_path)
        .context("Failed to clone FTC SDK")?;
    
    // Checkout specific version
    let obj = repo.revparse_single(FTC_SDK_VERSION)?;
    repo.checkout_tree(&obj, None)?;
    repo.set_head_detached(obj.id())?;
    
    // Create local.properties with Android SDK path
    create_local_properties(sdk_path, android_sdk_path)?;
    
    println!("{} FTC SDK installed successfully", "✓".green());
    
    Ok(())
}

fn create_local_properties(sdk_path: &Path, android_sdk_path: &Path) -> Result<()> {
    // Convert path to use forward slashes (works on both Windows and Unix)
    let android_sdk_str = android_sdk_path
        .display()
        .to_string()
        .replace("\\", "/");
    
    let local_properties = format!("sdk.dir={}\n", android_sdk_str);
    
    let properties_path = sdk_path.join("local.properties");
    fs::write(&properties_path, local_properties)
        .context("Failed to create local.properties")?;
    
    println!("{} Created local.properties with Android SDK path", "✓".green());
    
    Ok(())
}

fn check_version(sdk_path: &Path) -> Result<()> {
    let repo = Repository::open(sdk_path)?;
    
    // Get current HEAD
    let head = repo.head()?;
    let commit = head.peel_to_commit()?;
    
    // Try to find a tag for this commit
    let tag_names = repo.tag_names(None)?;
    let tags: Vec<_> = tag_names
        .iter()
        .filter_map(|t| t)
        .collect();
    
    println!("Current version: {}", 
        tags.first()
            .map(|t| t.to_string())
            .unwrap_or_else(|| format!("{}", commit.id()))
    );
    
    Ok(())
}

pub fn update(sdk_path: &Path) -> Result<()> {
    println!("{}", "Updating FTC SDK...".bright_yellow());
    
    let repo = Repository::open(sdk_path)
        .context("FTC SDK not found or not a git repository")?;
    
    // Fetch latest
    let mut remote = repo.find_remote("origin")?;
    remote.fetch(&["refs/tags/*:refs/tags/*"], None, None)?;
    
    // Checkout latest version
    let obj = repo.revparse_single(FTC_SDK_VERSION)?;
    repo.checkout_tree(&obj, None)?;
    repo.set_head_detached(obj.id())?;
    
    println!("{} FTC SDK updated to {}", "✓".green(), FTC_SDK_VERSION);
    
    Ok(())
}

pub fn verify(sdk_path: &Path) -> Result<()> {
    if !sdk_path.exists() {
        anyhow::bail!("FTC SDK not found at: {}", sdk_path.display());
    }
    
    // Check for essential directories
    let team_code = sdk_path.join("TeamCode");
    let ftc_robot_controller = sdk_path.join("FtcRobotController");
    
    if !team_code.exists() || !ftc_robot_controller.exists() {
        anyhow::bail!("FTC SDK incomplete: missing essential directories");
    }
    
    Ok(())
}

pub fn get_version(sdk_path: &Path) -> Result<String> {
    let repo = Repository::open(sdk_path)?;
    let head = repo.head()?;
    let commit = head.peel_to_commit()?;
    
    // Try to find a tag
    let tags = repo.tag_names(None)?;
    for tag in tags.iter().flatten() {
        let tag_ref = repo.find_reference(&format!("refs/tags/{}", tag))?;
        if let Ok(tag_commit) = tag_ref.peel_to_commit() {
            if tag_commit.id() == commit.id() {
                return Ok(tag.to_string());
            }
        }
    }
    
    Ok(format!("commit-{}", &commit.id().to_string()[..8]))
}