use clap::Parser;
use qr_core::qr::{QrCode, QrConfig, VersionMode};
use qr_core::version::EcLevel;
use std::path::Path;

#[derive(Parser)]
#[command(name = "qrgen", about = "QR 码生成器 — 从零手搓的 ISO/IEC 18004 实现")]
struct Args {
    /// 要编码的内容
    content: String,

    /// 输出文件 (.png 或 .svg)，不指定则输出终端 ASCII
    #[arg(short = 'o', long)]
    output: Option<String>,

    /// 纠错级别 [L/M/Q/H] [default: M]
    #[arg(short = 'l', long, default_value = "M")]
    level: String,

    /// 手动指定版本 (1-40)，不指定则自动选择
    #[arg(short = 'v', long)]
    version: Option<u8>,

    /// 模块像素大小（仅 PNG）[default: 4]
    #[arg(short = 's', long, default_value = "4")]
    size: u8,

    /// 白边模块数 [default: 4]
    #[arg(short = 'm', long, default_value = "4")]
    margin: u8,

    /// 反色（黑底白码）
    #[arg(long)]
    invert: bool,
}

fn main() -> anyhow::Result<()> {
    let args = Args::parse();

    let level = match args.level.to_uppercase().as_str() {
        "L" => EcLevel::L,
        "M" => EcLevel::M,
        "Q" => EcLevel::Q,
        "H" => EcLevel::H,
        _ => anyhow::bail!("无效纠错级别: {}。支持 L/M/Q/H", args.level),
    };

    let version = match args.version {
        Some(v) => {
            if !(1..=40).contains(&v) {
                anyhow::bail!("无效版本号: {}。支持 1-40", v);
            }
            VersionMode::Fixed(v)
        }
        None => VersionMode::Auto,
    };

    let config = QrConfig {
        level,
        version,
        margin: args.margin,
    };

    let qr =
        QrCode::encode(&args.content, config).map_err(|e| anyhow::anyhow!("编码失败: {}", e))?;

    match args.output {
        Some(path) => {
            let ext = Path::new(&path)
                .extension()
                .and_then(|e| e.to_str())
                .unwrap_or("")
                .to_lowercase();

            match ext.as_str() {
                "png" => {
                    let bytes = qr.to_png_bytes(args.size)?;
                    std::fs::write(&path, bytes)?;
                    println!(
                        "已生成: {} (版本 {}, {}×{} 模块, {} 级纠错)",
                        path,
                        qr.version.0,
                        qr.size(),
                        qr.size(),
                        match qr.level {
                            EcLevel::L => "L",
                            EcLevel::M => "M",
                            EcLevel::Q => "Q",
                            EcLevel::H => "H",
                        }
                    );
                }
                "svg" => {
                    let svg = qr.to_svg();
                    std::fs::write(&path, svg)?;
                    println!("已生成: {} (版本 {}, SVG 格式)", path, qr.version.0);
                }
                _ => anyhow::bail!("不支持的文件格式: .{}。支持 .png / .svg", ext),
            }
        }
        None => {
            // 终端 ASCII 输出
            println!("{}", qr.to_ascii(args.invert));
        }
    }

    Ok(())
}