use anyhow::{Result, bail};
use colored::*;
use std::path::PathBuf;
use std::fs;

pub fn upgrade_project(path: &str) -> Result<()> {
    let project_path = PathBuf::from(path);
    
    // Verify it's a weevil project (check for old .weevil-version or new .weevil.toml)
    let has_old_version = project_path.join(".weevil-version").exists();
    let has_config = project_path.join(".weevil.toml").exists();
    
    if !has_old_version && !has_config {
        bail!("Not a weevil project: {} (missing .weevil-version or .weevil.toml)", path);
    }
    
    println!("{}", format!("Upgrading project: {}", path).bright_yellow());
    println!();
    
    // Get SDK config
    let sdk_config = crate::sdk::SdkConfig::new()?;
    
    // Ensure FTC SDK has local.properties (in case it was installed before this feature)
    ensure_local_properties(&sdk_config)?;
    
    // Load or create project config
    let project_config = if has_config {
        println!("Found existing .weevil.toml");
        crate::project::ProjectConfig::load(&project_path)?
    } else {
        println!("Creating .weevil.toml (migrating from old format)");
        let project_name = project_path.file_name()
            .and_then(|n| n.to_str())
            .unwrap_or("unknown");
        crate::project::ProjectConfig::new(project_name, sdk_config.ftc_sdk_path.clone(), sdk_config.android_sdk_path.clone())?
    };
    
    println!("Current SDK: {}", project_config.ftc_sdk_path.display());
    println!("SDK Version: {}", project_config.ftc_sdk_version);
    println!();
    
    // Files that are safe to overwrite (infrastructure, not user code)
    let safe_to_overwrite = vec![
        "build.gradle.kts",
        "settings.gradle.kts",
        "build.sh",
        "build.bat",
        "deploy.sh",
        "deploy.bat",
        "gradlew",
        "gradlew.bat",
        "gradle/wrapper/gradle-wrapper.properties",
        "gradle/wrapper/gradle-wrapper.jar",
        ".gitignore",
        // Android Studio integration — regenerated so run configs stay in
        // sync if deploy.sh flags or script names ever change.
        ".idea/workspace.xml",
        ".idea/runConfigurations/Build.xml",
        ".idea/runConfigurations/Build (Windows).xml",
        ".idea/runConfigurations/Deploy (auto).xml",
        ".idea/runConfigurations/Deploy (auto) (Windows).xml",
        ".idea/runConfigurations/Deploy (USB).xml",
        ".idea/runConfigurations/Deploy (USB) (Windows).xml",
        ".idea/runConfigurations/Deploy (WiFi).xml",
        ".idea/runConfigurations/Deploy (WiFi) (Windows).xml",
        ".idea/runConfigurations/Test.xml",
        ".idea/runConfigurations/Test (Windows).xml",
    ];
    
    println!("{}", "Updating infrastructure files...".bright_yellow());
    
    // Create a modified SDK config that uses the project's configured FTC SDK
    let project_sdk_config = crate::sdk::SdkConfig {
        ftc_sdk_path: project_config.ftc_sdk_path.clone(),
        android_sdk_path: sdk_config.android_sdk_path.clone(),
        cache_dir: sdk_config.cache_dir.clone(),
    };
    
    // Regenerate safe files using the project's configured SDK
    let builder = crate::project::ProjectBuilder::new(
        &project_config.project_name,
        &project_sdk_config
    )?;
    
    // Temporarily create files in a temp location
    let temp_dir = tempfile::tempdir()?;
    builder.create(temp_dir.path(), &project_sdk_config)?;
    
    // Copy only the safe files
    for file in safe_to_overwrite {
        let src = temp_dir.path().join(file);
        let dst = project_path.join(file);
        
        if src.exists() {
            if let Some(parent) = dst.parent() {
                fs::create_dir_all(parent)?;
            }
            fs::copy(&src, &dst)?;
            println!("  {} {}", "✓".green(), file);
            
            // Make executable if needed
            #[cfg(unix)]
            if file.ends_with(".sh") || file == "gradlew" {
                use std::os::unix::fs::PermissionsExt;
                let mut perms = fs::metadata(&dst)?.permissions();
                perms.set_mode(0o755);
                fs::set_permissions(&dst, perms)?;
            }
        }
    }
    
    // Save/update the config
    project_config.save(&project_path)?;
    println!("  {} {}", "✓".green(), ".weevil.toml");
    
    // Remove old version marker if it exists
    let old_version_file = project_path.join(".weevil-version");
    if old_version_file.exists() {
        fs::remove_file(old_version_file)?;
        println!("  {} {}", "✓".green(), "Removed old .weevil-version");
    }
    
    println!();
    println!("{}", "═══════════════════════════════════════════════════════════".bright_green());
    println!("{}", "   ✓ Project Upgraded!".bright_green().bold());
    println!("{}", "═══════════════════════════════════════════════════════════".bright_green());
    println!();
    println!("{}", "Your code in src/ was preserved.".green());
    println!("{}", "Build scripts and gradle configuration updated.".green());
    println!();
    println!("Test it: ./gradlew test");
    println!();
    
    Ok(())
}

fn ensure_local_properties(sdk_config: &crate::sdk::SdkConfig) -> Result<()> {
    let local_properties_path = sdk_config.ftc_sdk_path.join("local.properties");
    
    if !local_properties_path.exists() {
        println!("Creating local.properties in FTC SDK...");
        let android_sdk_str = sdk_config.android_sdk_path
            .display()
            .to_string()
            .replace("\\", "/");
        
        let local_properties = format!("sdk.dir={}\n", android_sdk_str);
        fs::write(&local_properties_path, local_properties)?;
        println!("{} Created local.properties", "✓".green());
    }
    
    Ok(())
}