use serde::Serialize;
use std::sync::OnceLock;

/// QR 码纠错级别
///
/// 决定 QR 码被遮挡/损毁后仍可扫描的能力。纠错越强，可存储的数据越少。
///
/// ```rust
/// use qr_core::version::{EcLevel, Version};
///
/// let ver = Version::new(1).unwrap();
/// let h = ver.ec_info(EcLevel::H);
/// let l = ver.ec_info(EcLevel::L);
/// // H 级纠错码字更多，数据码字更少
/// assert!(h.ec_per_block > l.ec_per_block);
/// ```
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize)]
pub enum EcLevel {
    /// L 级 — 约 7% 纠错能力
    L,
    /// M 级 — 约 15% 纠错能力（默认）
    M,
    /// Q 级 — 约 25% 纠错能力
    Q,
    /// H 级 — 约 30% 纠错能力
    H,
}

impl EcLevel {
    /// 格式信息中使用的 2-bit 指示位
    pub fn indicator_bits(self) -> u8 {
        match self {
            EcLevel::L => 0b01,
            EcLevel::M => 0b00,
            EcLevel::Q => 0b11,
            EcLevel::H => 0b10,
        }
    }
}

/// QR 码版本号（1~40）
///
/// 版本决定 QR 码的物理尺寸：`side = 17 + version × 4` 模块。
/// 版本 1 是 21×21，版本 40 是 177×177。
///
/// ```rust
/// use qr_core::version::Version;
///
/// let v1 = Version::new(1).unwrap();
/// assert_eq!(v1.size(), 21);
///
/// let v40 = Version::new(40).unwrap();
/// assert_eq!(v40.size(), 177);
///
/// assert!(Version::new(0).is_none());
/// assert!(Version::new(41).is_none());
/// ```
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize)]
pub struct Version(pub u8);

impl Version {
    pub fn new(v: u8) -> Option<Self> {
        if (1..=40).contains(&v) {
            Some(Version(v))
        } else {
            None
        }
    }

    /// QR 码边长（模块数）
    pub fn size(self) -> u8 {
        17 + self.0 * 4
    }

    /// 对齐图案位置列表
    pub fn alignment_positions(self) -> &'static [u8] {
        ALIGNMENT_POSITIONS[self.0 as usize - 1]
    }

    /// 获取该版本+级别的纠错信息
    pub fn ec_info(self, level: EcLevel) -> EcInfo {
        let row = &VERSION_TABLE[self.0 as usize - 1];
        let (total, ec_per_block, g1_blocks, g1_data, g2_blocks, g2_data) = match level {
            EcLevel::L => (
                row.l_total,
                row.l_ec,
                row.l_g1,
                row.l_g1_data,
                row.l_g2,
                row.l_g2_data,
            ),
            EcLevel::M => (
                row.m_total,
                row.m_ec,
                row.m_g1,
                row.m_g1_data,
                row.m_g2,
                row.m_g2_data,
            ),
            EcLevel::Q => (
                row.q_total,
                row.q_ec,
                row.q_g1,
                row.q_g1_data,
                row.q_g2,
                row.q_g2_data,
            ),
            EcLevel::H => (
                row.h_total,
                row.h_ec,
                row.h_g1,
                row.h_g1_data,
                row.h_g2,
                row.h_g2_data,
            ),
        };
        let mut blocks = Vec::new();
        if g1_blocks > 0 {
            blocks.push(BlockInfo {
                count: g1_blocks,
                data_codewords: g1_data,
            });
        }
        if g2_blocks > 0 {
            blocks.push(BlockInfo {
                count: g2_blocks,
                data_codewords: g2_data,
            });
        }

        EcInfo {
            total_codewords: total,
            ec_per_block,
            blocks,
        }
    }
}

/// 纠错分组信息
///
/// 一组 QR 数据被分为多个块，每个块独立计算 RS 纠错码。
#[derive(Debug, Clone)]
pub struct EcInfo {
    /// 数据码字总数
    pub total_codewords: u16,
    /// 每个块的纠错码字数
    pub ec_per_block: u8,
    /// 分组信息（1~2 组，不同数据码字数）
    pub blocks: Vec<BlockInfo>,
}

/// 单个分组信息
///
/// 所有块的数据码字总数 + 纠错码字总数 = QR 码总容量。
#[derive(Debug, Clone)]
pub struct BlockInfo {
    /// 该组块数
    pub count: u16,
    /// 每个块的数据码字数
    pub data_codewords: u16,
}

/// 单行版本数据
struct VersionRow {
    l_total: u16,
    l_ec: u8,
    l_g1: u16,
    l_g1_data: u16,
    l_g2: u16,
    l_g2_data: u16,
    m_total: u16,
    m_ec: u8,
    m_g1: u16,
    m_g1_data: u16,
    m_g2: u16,
    m_g2_data: u16,
    q_total: u16,
    q_ec: u8,
    q_g1: u16,
    q_g1_data: u16,
    q_g2: u16,
    q_g2_data: u16,
    h_total: u16,
    h_ec: u8,
    h_g1: u16,
    h_g1_data: u16,
    h_g2: u16,
    h_g2_data: u16,
}

/// ISO 18004 附录 I — 40 版本 × 4 纠错级别的容量表
/// 格式: (总码字数, EC码字/块, 组1块数, 组1数据码字数, 组2块数, 组2数据码字数)
/// 当 g2_data == 0 时，表示仅有一组
static VERSION_TABLE: [VersionRow; 40] = [
    // 版本 1
    VersionRow {
        l_total: 26,
        l_ec: 7,
        l_g1: 1,
        l_g1_data: 19,
        l_g2: 0,
        l_g2_data: 0,
        m_total: 26,
        m_ec: 10,
        m_g1: 1,
        m_g1_data: 16,
        m_g2: 0,
        m_g2_data: 0,
        q_total: 26,
        q_ec: 13,
        q_g1: 1,
        q_g1_data: 13,
        q_g2: 0,
        q_g2_data: 0,
        h_total: 26,
        h_ec: 17,
        h_g1: 1,
        h_g1_data: 9,
        h_g2: 0,
        h_g2_data: 0,
    },
    // 版本 2
    VersionRow {
        l_total: 44,
        l_ec: 10,
        l_g1: 1,
        l_g1_data: 34,
        l_g2: 0,
        l_g2_data: 0,
        m_total: 44,
        m_ec: 16,
        m_g1: 1,
        m_g1_data: 28,
        m_g2: 0,
        m_g2_data: 0,
        q_total: 44,
        q_ec: 22,
        q_g1: 1,
        q_g1_data: 22,
        q_g2: 0,
        q_g2_data: 0,
        h_total: 44,
        h_ec: 28,
        h_g1: 1,
        h_g1_data: 16,
        h_g2: 0,
        h_g2_data: 0,
    },
    // 版本 3
    VersionRow {
        l_total: 70,
        l_ec: 15,
        l_g1: 1,
        l_g1_data: 55,
        l_g2: 0,
        l_g2_data: 0,
        m_total: 70,
        m_ec: 26,
        m_g1: 1,
        m_g1_data: 44,
        m_g2: 0,
        m_g2_data: 0,
        q_total: 70,
        q_ec: 18,
        q_g1: 2,
        q_g1_data: 17,
        q_g2: 0,
        q_g2_data: 0,
        h_total: 70,
        h_ec: 22,
        h_g1: 2,
        h_g1_data: 13,
        h_g2: 0,
        h_g2_data: 0,
    },
    // 版本 4
    VersionRow {
        l_total: 100,
        l_ec: 20,
        l_g1: 1,
        l_g1_data: 80,
        l_g2: 0,
        l_g2_data: 0,
        m_total: 100,
        m_ec: 18,
        m_g1: 2,
        m_g1_data: 32,
        m_g2: 0,
        m_g2_data: 0,
        q_total: 100,
        q_ec: 26,
        q_g1: 2,
        q_g1_data: 24,
        q_g2: 0,
        q_g2_data: 0,
        h_total: 100,
        h_ec: 16,
        h_g1: 4,
        h_g1_data: 9,
        h_g2: 0,
        h_g2_data: 0,
    },
    // 版本 5
    VersionRow {
        l_total: 134,
        l_ec: 26,
        l_g1: 1,
        l_g1_data: 108,
        l_g2: 0,
        l_g2_data: 0,
        m_total: 134,
        m_ec: 24,
        m_g1: 2,
        m_g1_data: 43,
        m_g2: 0,
        m_g2_data: 0,
        q_total: 134,
        q_ec: 18,
        q_g1: 2,
        q_g1_data: 15,
        q_g2: 2,
        q_g2_data: 16,
        h_total: 134,
        h_ec: 22,
        h_g1: 2,
        h_g1_data: 11,
        h_g2: 2,
        h_g2_data: 12,
    },
    // 版本 6
    VersionRow {
        l_total: 172,
        l_ec: 18,
        l_g1: 2,
        l_g1_data: 68,
        l_g2: 0,
        l_g2_data: 0,
        m_total: 172,
        m_ec: 16,
        m_g1: 4,
        m_g1_data: 27,
        m_g2: 0,
        m_g2_data: 0,
        q_total: 172,
        q_ec: 24,
        q_g1: 4,
        q_g1_data: 19,
        q_g2: 0,
        q_g2_data: 0,
        h_total: 172,
        h_ec: 28,
        h_g1: 4,
        h_g1_data: 15,
        h_g2: 0,
        h_g2_data: 0,
    },
    // 版本 7
    VersionRow {
        l_total: 196,
        l_ec: 20,
        l_g1: 2,
        l_g1_data: 78,
        l_g2: 0,
        l_g2_data: 0,
        m_total: 196,
        m_ec: 18,
        m_g1: 4,
        m_g1_data: 31,
        m_g2: 0,
        m_g2_data: 0,
        q_total: 196,
        q_ec: 18,
        q_g1: 2,
        q_g1_data: 14,
        q_g2: 4,
        q_g2_data: 15,
        h_total: 196,
        h_ec: 26,
        h_g1: 4,
        h_g1_data: 13,
        h_g2: 1,
        h_g2_data: 14,
    },
    // 版本 8
    VersionRow {
        l_total: 242,
        l_ec: 24,
        l_g1: 2,
        l_g1_data: 97,
        l_g2: 0,
        l_g2_data: 0,
        m_total: 242,
        m_ec: 22,
        m_g1: 2,
        m_g1_data: 38,
        m_g2: 2,
        m_g2_data: 39,
        q_total: 242,
        q_ec: 22,
        q_g1: 4,
        q_g1_data: 18,
        q_g2: 2,
        q_g2_data: 19,
        h_total: 242,
        h_ec: 26,
        h_g1: 4,
        h_g1_data: 14,
        h_g2: 2,
        h_g2_data: 15,
    },
    // 版本 9
    VersionRow {
        l_total: 292,
        l_ec: 30,
        l_g1: 2,
        l_g1_data: 116,
        l_g2: 0,
        l_g2_data: 0,
        m_total: 292,
        m_ec: 22,
        m_g1: 3,
        m_g1_data: 36,
        m_g2: 2,
        m_g2_data: 37,
        q_total: 292,
        q_ec: 20,
        q_g1: 4,
        q_g1_data: 16,
        q_g2: 4,
        q_g2_data: 17,
        h_total: 292,
        h_ec: 24,
        h_g1: 4,
        h_g1_data: 12,
        h_g2: 4,
        h_g2_data: 13,
    },
    // 版本 10
    VersionRow {
        l_total: 346,
        l_ec: 18,
        l_g1: 2,
        l_g1_data: 68,
        l_g2: 2,
        l_g2_data: 69,
        m_total: 346,
        m_ec: 26,
        m_g1: 4,
        m_g1_data: 43,
        m_g2: 1,
        m_g2_data: 44,
        q_total: 346,
        q_ec: 24,
        q_g1: 6,
        q_g1_data: 19,
        q_g2: 2,
        q_g2_data: 20,
        h_total: 346,
        h_ec: 28,
        h_g1: 6,
        h_g1_data: 15,
        h_g2: 2,
        h_g2_data: 16,
    },
    // 版本 11
    VersionRow {
        l_total: 404,
        l_ec: 20,
        l_g1: 4,
        l_g1_data: 81,
        l_g2: 0,
        l_g2_data: 0,
        m_total: 404,
        m_ec: 30,
        m_g1: 1,
        m_g1_data: 50,
        m_g2: 4,
        m_g2_data: 51,
        q_total: 404,
        q_ec: 28,
        q_g1: 4,
        q_g1_data: 22,
        q_g2: 4,
        q_g2_data: 23,
        h_total: 404,
        h_ec: 24,
        h_g1: 3,
        h_g1_data: 12,
        h_g2: 8,
        h_g2_data: 13,
    },
    // 版本 12
    VersionRow {
        l_total: 466,
        l_ec: 24,
        l_g1: 2,
        l_g1_data: 92,
        l_g2: 2,
        l_g2_data: 93,
        m_total: 466,
        m_ec: 22,
        m_g1: 6,
        m_g1_data: 36,
        m_g2: 2,
        m_g2_data: 37,
        q_total: 466,
        q_ec: 26,
        q_g1: 4,
        q_g1_data: 20,
        q_g2: 6,
        q_g2_data: 21,
        h_total: 466,
        h_ec: 28,
        h_g1: 7,
        h_g1_data: 14,
        h_g2: 4,
        h_g2_data: 15,
    },
    // 版本 13
    VersionRow {
        l_total: 532,
        l_ec: 26,
        l_g1: 4,
        l_g1_data: 107,
        l_g2: 0,
        l_g2_data: 0,
        m_total: 532,
        m_ec: 22,
        m_g1: 8,
        m_g1_data: 37,
        m_g2: 1,
        m_g2_data: 38,
        q_total: 532,
        q_ec: 24,
        q_g1: 8,
        q_g1_data: 20,
        q_g2: 4,
        q_g2_data: 21,
        h_total: 532,
        h_ec: 22,
        h_g1: 12,
        h_g1_data: 11,
        h_g2: 4,
        h_g2_data: 12,
    },
    // 版本 14
    VersionRow {
        l_total: 581,
        l_ec: 30,
        l_g1: 3,
        l_g1_data: 115,
        l_g2: 1,
        l_g2_data: 116,
        m_total: 581,
        m_ec: 24,
        m_g1: 4,
        m_g1_data: 40,
        m_g2: 5,
        m_g2_data: 41,
        q_total: 581,
        q_ec: 20,
        q_g1: 11,
        q_g1_data: 16,
        q_g2: 5,
        q_g2_data: 17,
        h_total: 581,
        h_ec: 24,
        h_g1: 11,
        h_g1_data: 12,
        h_g2: 5,
        h_g2_data: 13,
    },
    // 版本 15
    VersionRow {
        l_total: 655,
        l_ec: 22,
        l_g1: 5,
        l_g1_data: 87,
        l_g2: 1,
        l_g2_data: 88,
        m_total: 655,
        m_ec: 24,
        m_g1: 5,
        m_g1_data: 41,
        m_g2: 5,
        m_g2_data: 42,
        q_total: 655,
        q_ec: 30,
        q_g1: 5,
        q_g1_data: 24,
        q_g2: 7,
        q_g2_data: 25,
        h_total: 655,
        h_ec: 24,
        h_g1: 11,
        h_g1_data: 12,
        h_g2: 7,
        h_g2_data: 13,
    },
    // 版本 16
    VersionRow {
        l_total: 733,
        l_ec: 24,
        l_g1: 5,
        l_g1_data: 98,
        l_g2: 1,
        l_g2_data: 99,
        m_total: 733,
        m_ec: 28,
        m_g1: 7,
        m_g1_data: 45,
        m_g2: 3,
        m_g2_data: 46,
        q_total: 733,
        q_ec: 24,
        q_g1: 15,
        q_g1_data: 19,
        q_g2: 2,
        q_g2_data: 20,
        h_total: 733,
        h_ec: 30,
        h_g1: 3,
        h_g1_data: 15,
        h_g2: 13,
        h_g2_data: 16,
    },
    // 版本 17
    VersionRow {
        l_total: 815,
        l_ec: 28,
        l_g1: 1,
        l_g1_data: 107,
        l_g2: 5,
        l_g2_data: 108,
        m_total: 815,
        m_ec: 28,
        m_g1: 10,
        m_g1_data: 46,
        m_g2: 1,
        m_g2_data: 47,
        q_total: 815,
        q_ec: 28,
        q_g1: 1,
        q_g1_data: 22,
        q_g2: 15,
        q_g2_data: 23,
        h_total: 815,
        h_ec: 28,
        h_g1: 2,
        h_g1_data: 14,
        h_g2: 17,
        h_g2_data: 15,
    },
    // 版本 18
    VersionRow {
        l_total: 901,
        l_ec: 30,
        l_g1: 5,
        l_g1_data: 120,
        l_g2: 1,
        l_g2_data: 121,
        m_total: 901,
        m_ec: 26,
        m_g1: 9,
        m_g1_data: 43,
        m_g2: 4,
        m_g2_data: 44,
        q_total: 901,
        q_ec: 28,
        q_g1: 17,
        q_g1_data: 22,
        q_g2: 1,
        q_g2_data: 23,
        h_total: 901,
        h_ec: 28,
        h_g1: 2,
        h_g1_data: 14,
        h_g2: 19,
        h_g2_data: 15,
    },
    // 版本 19
    VersionRow {
        l_total: 991,
        l_ec: 28,
        l_g1: 3,
        l_g1_data: 113,
        l_g2: 4,
        l_g2_data: 114,
        m_total: 991,
        m_ec: 26,
        m_g1: 3,
        m_g1_data: 44,
        m_g2: 11,
        m_g2_data: 45,
        q_total: 991,
        q_ec: 26,
        q_g1: 17,
        q_g1_data: 21,
        q_g2: 4,
        q_g2_data: 22,
        h_total: 991,
        h_ec: 26,
        h_g1: 9,
        h_g1_data: 13,
        h_g2: 16,
        h_g2_data: 14,
    },
    // 版本 20
    VersionRow {
        l_total: 1085,
        l_ec: 28,
        l_g1: 3,
        l_g1_data: 107,
        l_g2: 5,
        l_g2_data: 108,
        m_total: 1085,
        m_ec: 26,
        m_g1: 3,
        m_g1_data: 41,
        m_g2: 13,
        m_g2_data: 42,
        q_total: 1085,
        q_ec: 30,
        q_g1: 15,
        q_g1_data: 24,
        q_g2: 5,
        q_g2_data: 25,
        h_total: 1085,
        h_ec: 28,
        h_g1: 15,
        h_g1_data: 15,
        h_g2: 10,
        h_g2_data: 16,
    },
    // 版本 21
    VersionRow {
        l_total: 1156,
        l_ec: 28,
        l_g1: 4,
        l_g1_data: 116,
        l_g2: 4,
        l_g2_data: 117,
        m_total: 1156,
        m_ec: 26,
        m_g1: 17,
        m_g1_data: 42,
        m_g2: 0,
        m_g2_data: 0,
        q_total: 1156,
        q_ec: 28,
        q_g1: 17,
        q_g1_data: 22,
        q_g2: 6,
        q_g2_data: 23,
        h_total: 1156,
        h_ec: 30,
        h_g1: 19,
        h_g1_data: 16,
        h_g2: 6,
        h_g2_data: 17,
    },
    // 版本 22
    VersionRow {
        l_total: 1258,
        l_ec: 28,
        l_g1: 2,
        l_g1_data: 111,
        l_g2: 7,
        l_g2_data: 112,
        m_total: 1258,
        m_ec: 28,
        m_g1: 17,
        m_g1_data: 46,
        m_g2: 0,
        m_g2_data: 0,
        q_total: 1258,
        q_ec: 30,
        q_g1: 7,
        q_g1_data: 24,
        q_g2: 16,
        q_g2_data: 25,
        h_total: 1258,
        h_ec: 24,
        h_g1: 34,
        h_g1_data: 13,
        h_g2: 0,
        h_g2_data: 0,
    },
    // 版本 23
    VersionRow {
        l_total: 1364,
        l_ec: 30,
        l_g1: 4,
        l_g1_data: 121,
        l_g2: 5,
        l_g2_data: 122,
        m_total: 1364,
        m_ec: 28,
        m_g1: 4,
        m_g1_data: 47,
        m_g2: 14,
        m_g2_data: 48,
        q_total: 1364,
        q_ec: 30,
        q_g1: 11,
        q_g1_data: 24,
        q_g2: 14,
        q_g2_data: 25,
        h_total: 1364,
        h_ec: 30,
        h_g1: 16,
        h_g1_data: 15,
        h_g2: 14,
        h_g2_data: 16,
    },
    // 版本 24
    VersionRow {
        l_total: 1474,
        l_ec: 30,
        l_g1: 6,
        l_g1_data: 117,
        l_g2: 4,
        l_g2_data: 118,
        m_total: 1474,
        m_ec: 28,
        m_g1: 6,
        m_g1_data: 45,
        m_g2: 14,
        m_g2_data: 46,
        q_total: 1474,
        q_ec: 30,
        q_g1: 11,
        q_g1_data: 24,
        q_g2: 16,
        q_g2_data: 25,
        h_total: 1474,
        h_ec: 30,
        h_g1: 30,
        h_g1_data: 16,
        h_g2: 2,
        h_g2_data: 17,
    },
    // 版本 25
    VersionRow {
        l_total: 1588,
        l_ec: 26,
        l_g1: 8,
        l_g1_data: 106,
        l_g2: 4,
        l_g2_data: 107,
        m_total: 1588,
        m_ec: 28,
        m_g1: 8,
        m_g1_data: 47,
        m_g2: 13,
        m_g2_data: 48,
        q_total: 1588,
        q_ec: 30,
        q_g1: 7,
        q_g1_data: 24,
        q_g2: 22,
        q_g2_data: 25,
        h_total: 1588,
        h_ec: 30,
        h_g1: 22,
        h_g1_data: 15,
        h_g2: 13,
        h_g2_data: 16,
    },
    // 版本 26
    VersionRow {
        l_total: 1706,
        l_ec: 28,
        l_g1: 10,
        l_g1_data: 114,
        l_g2: 2,
        l_g2_data: 115,
        m_total: 1706,
        m_ec: 28,
        m_g1: 19,
        m_g1_data: 46,
        m_g2: 4,
        m_g2_data: 47,
        q_total: 1706,
        q_ec: 28,
        q_g1: 28,
        q_g1_data: 22,
        q_g2: 6,
        q_g2_data: 23,
        h_total: 1706,
        h_ec: 30,
        h_g1: 33,
        h_g1_data: 16,
        h_g2: 4,
        h_g2_data: 17,
    },
    // 版本 27
    VersionRow {
        l_total: 1828,
        l_ec: 30,
        l_g1: 8,
        l_g1_data: 122,
        l_g2: 4,
        l_g2_data: 123,
        m_total: 1828,
        m_ec: 28,
        m_g1: 22,
        m_g1_data: 45,
        m_g2: 3,
        m_g2_data: 46,
        q_total: 1828,
        q_ec: 30,
        q_g1: 8,
        q_g1_data: 23,
        q_g2: 26,
        q_g2_data: 24,
        h_total: 1828,
        h_ec: 30,
        h_g1: 12,
        h_g1_data: 15,
        h_g2: 28,
        h_g2_data: 16,
    },
    // 版本 28
    VersionRow {
        l_total: 1921,
        l_ec: 30,
        l_g1: 3,
        l_g1_data: 117,
        l_g2: 10,
        l_g2_data: 118,
        m_total: 1921,
        m_ec: 28,
        m_g1: 3,
        m_g1_data: 45,
        m_g2: 23,
        m_g2_data: 46,
        q_total: 1921,
        q_ec: 30,
        q_g1: 4,
        q_g1_data: 24,
        q_g2: 31,
        q_g2_data: 25,
        h_total: 1921,
        h_ec: 30,
        h_g1: 11,
        h_g1_data: 15,
        h_g2: 31,
        h_g2_data: 16,
    },
    // 版本 29
    VersionRow {
        l_total: 2051,
        l_ec: 30,
        l_g1: 7,
        l_g1_data: 116,
        l_g2: 7,
        l_g2_data: 117,
        m_total: 2051,
        m_ec: 28,
        m_g1: 21,
        m_g1_data: 45,
        m_g2: 7,
        m_g2_data: 46,
        q_total: 2051,
        q_ec: 30,
        q_g1: 1,
        q_g1_data: 23,
        q_g2: 37,
        q_g2_data: 24,
        h_total: 2051,
        h_ec: 30,
        h_g1: 19,
        h_g1_data: 15,
        h_g2: 26,
        h_g2_data: 16,
    },
    // 版本 30
    VersionRow {
        l_total: 2185,
        l_ec: 30,
        l_g1: 5,
        l_g1_data: 115,
        l_g2: 10,
        l_g2_data: 116,
        m_total: 2185,
        m_ec: 28,
        m_g1: 19,
        m_g1_data: 47,
        m_g2: 10,
        m_g2_data: 48,
        q_total: 2185,
        q_ec: 30,
        q_g1: 15,
        q_g1_data: 24,
        q_g2: 25,
        q_g2_data: 25,
        h_total: 2185,
        h_ec: 30,
        h_g1: 23,
        h_g1_data: 15,
        h_g2: 25,
        h_g2_data: 16,
    },
    // 版本 31
    VersionRow {
        l_total: 2323,
        l_ec: 30,
        l_g1: 13,
        l_g1_data: 115,
        l_g2: 3,
        l_g2_data: 116,
        m_total: 2323,
        m_ec: 28,
        m_g1: 2,
        m_g1_data: 46,
        m_g2: 29,
        m_g2_data: 47,
        q_total: 2323,
        q_ec: 30,
        q_g1: 42,
        q_g1_data: 24,
        q_g2: 1,
        q_g2_data: 25,
        h_total: 2323,
        h_ec: 30,
        h_g1: 23,
        h_g1_data: 15,
        h_g2: 28,
        h_g2_data: 16,
    },
    // 版本 32
    VersionRow {
        l_total: 2465,
        l_ec: 30,
        l_g1: 17,
        l_g1_data: 115,
        l_g2: 0,
        l_g2_data: 0,
        m_total: 2465,
        m_ec: 28,
        m_g1: 10,
        m_g1_data: 46,
        m_g2: 23,
        m_g2_data: 47,
        q_total: 2465,
        q_ec: 30,
        q_g1: 10,
        q_g1_data: 24,
        q_g2: 35,
        q_g2_data: 25,
        h_total: 2465,
        h_ec: 30,
        h_g1: 19,
        h_g1_data: 15,
        h_g2: 35,
        h_g2_data: 16,
    },
    // 版本 33
    VersionRow {
        l_total: 2611,
        l_ec: 30,
        l_g1: 17,
        l_g1_data: 115,
        l_g2: 1,
        l_g2_data: 116,
        m_total: 2611,
        m_ec: 28,
        m_g1: 14,
        m_g1_data: 46,
        m_g2: 21,
        m_g2_data: 47,
        q_total: 2611,
        q_ec: 30,
        q_g1: 29,
        q_g1_data: 24,
        q_g2: 19,
        q_g2_data: 25,
        h_total: 2611,
        h_ec: 30,
        h_g1: 11,
        h_g1_data: 15,
        h_g2: 46,
        h_g2_data: 16,
    },
    // 版本 34
    VersionRow {
        l_total: 2761,
        l_ec: 30,
        l_g1: 13,
        l_g1_data: 115,
        l_g2: 6,
        l_g2_data: 116,
        m_total: 2761,
        m_ec: 28,
        m_g1: 14,
        m_g1_data: 46,
        m_g2: 23,
        m_g2_data: 47,
        q_total: 2761,
        q_ec: 30,
        q_g1: 44,
        q_g1_data: 24,
        q_g2: 7,
        q_g2_data: 25,
        h_total: 2761,
        h_ec: 30,
        h_g1: 59,
        h_g1_data: 16,
        h_g2: 1,
        h_g2_data: 17,
    },
    // 版本 35
    VersionRow {
        l_total: 2876,
        l_ec: 30,
        l_g1: 12,
        l_g1_data: 121,
        l_g2: 7,
        l_g2_data: 122,
        m_total: 2876,
        m_ec: 28,
        m_g1: 12,
        m_g1_data: 47,
        m_g2: 26,
        m_g2_data: 48,
        q_total: 2876,
        q_ec: 30,
        q_g1: 39,
        q_g1_data: 24,
        q_g2: 14,
        q_g2_data: 25,
        h_total: 2876,
        h_ec: 30,
        h_g1: 22,
        h_g1_data: 15,
        h_g2: 41,
        h_g2_data: 16,
    },
    // 版本 36
    VersionRow {
        l_total: 3034,
        l_ec: 30,
        l_g1: 6,
        l_g1_data: 121,
        l_g2: 14,
        l_g2_data: 122,
        m_total: 3034,
        m_ec: 28,
        m_g1: 6,
        m_g1_data: 47,
        m_g2: 34,
        m_g2_data: 48,
        q_total: 3034,
        q_ec: 30,
        q_g1: 46,
        q_g1_data: 24,
        q_g2: 10,
        q_g2_data: 25,
        h_total: 3034,
        h_ec: 30,
        h_g1: 2,
        h_g1_data: 15,
        h_g2: 64,
        h_g2_data: 16,
    },
    // 版本 37
    VersionRow {
        l_total: 3196,
        l_ec: 30,
        l_g1: 17,
        l_g1_data: 122,
        l_g2: 4,
        l_g2_data: 123,
        m_total: 3196,
        m_ec: 28,
        m_g1: 29,
        m_g1_data: 46,
        m_g2: 14,
        m_g2_data: 47,
        q_total: 3196,
        q_ec: 30,
        q_g1: 49,
        q_g1_data: 24,
        q_g2: 10,
        q_g2_data: 25,
        h_total: 3196,
        h_ec: 30,
        h_g1: 24,
        h_g1_data: 15,
        h_g2: 46,
        h_g2_data: 16,
    },
    // 版本 38
    VersionRow {
        l_total: 3362,
        l_ec: 30,
        l_g1: 4,
        l_g1_data: 122,
        l_g2: 18,
        l_g2_data: 123,
        m_total: 3362,
        m_ec: 28,
        m_g1: 13,
        m_g1_data: 46,
        m_g2: 32,
        m_g2_data: 47,
        q_total: 3362,
        q_ec: 30,
        q_g1: 48,
        q_g1_data: 24,
        q_g2: 14,
        q_g2_data: 25,
        h_total: 3362,
        h_ec: 30,
        h_g1: 42,
        h_g1_data: 15,
        h_g2: 32,
        h_g2_data: 16,
    },
    // 版本 39
    VersionRow {
        l_total: 3532,
        l_ec: 30,
        l_g1: 20,
        l_g1_data: 117,
        l_g2: 4,
        l_g2_data: 118,
        m_total: 3532,
        m_ec: 28,
        m_g1: 40,
        m_g1_data: 47,
        m_g2: 7,
        m_g2_data: 48,
        q_total: 3532,
        q_ec: 30,
        q_g1: 43,
        q_g1_data: 24,
        q_g2: 22,
        q_g2_data: 25,
        h_total: 3532,
        h_ec: 30,
        h_g1: 10,
        h_g1_data: 15,
        h_g2: 67,
        h_g2_data: 16,
    },
    // 版本 40
    VersionRow {
        l_total: 3706,
        l_ec: 30,
        l_g1: 19,
        l_g1_data: 118,
        l_g2: 6,
        l_g2_data: 119,
        m_total: 3706,
        m_ec: 28,
        m_g1: 18,
        m_g1_data: 47,
        m_g2: 31,
        m_g2_data: 48,
        q_total: 3706,
        q_ec: 30,
        q_g1: 34,
        q_g1_data: 24,
        q_g2: 34,
        q_g2_data: 25,
        h_total: 3706,
        h_ec: 30,
        h_g1: 20,
        h_g1_data: 15,
        h_g2: 61,
        h_g2_data: 16,
    },
];

// 对齐图案中心位置表（每个版本的坐标数组）
static ALIGNMENT_POSITIONS: [&[u8]; 40] = [
    &[],                             // v1  (无对齐图案)
    &[6, 18],                        // v2
    &[6, 22],                        // v3
    &[6, 26],                        // v4
    &[6, 30],                        // v5
    &[6, 34],                        // v6
    &[6, 22, 38],                    // v7
    &[6, 24, 42],                    // v8
    &[6, 26, 46],                    // v9
    &[6, 28, 50],                    // v10
    &[6, 30, 54],                    // v11
    &[6, 32, 58],                    // v12
    &[6, 34, 62],                    // v13
    &[6, 26, 46, 66],                // v14
    &[6, 26, 48, 70],                // v15
    &[6, 26, 50, 74],                // v16
    &[6, 30, 54, 78],                // v17
    &[6, 30, 56, 82],                // v18
    &[6, 30, 58, 86],                // v19
    &[6, 34, 62, 90],                // v20
    &[6, 28, 50, 72, 94],            // v21
    &[6, 26, 50, 74, 98],            // v22
    &[6, 30, 54, 78, 102],           // v23
    &[6, 28, 54, 80, 106],           // v24
    &[6, 32, 58, 84, 110],           // v25
    &[6, 30, 58, 86, 114],           // v26
    &[6, 34, 62, 90, 118],           // v27
    &[6, 26, 50, 74, 98, 122],       // v28
    &[6, 30, 54, 78, 102, 126],      // v29
    &[6, 26, 52, 78, 104, 130],      // v30
    &[6, 30, 56, 82, 108, 134],      // v31
    &[6, 34, 60, 86, 112, 138],      // v32
    &[6, 30, 58, 86, 114, 142],      // v33
    &[6, 34, 62, 90, 118, 146],      // v34
    &[6, 30, 54, 78, 102, 126, 150], // v35
    &[6, 24, 50, 76, 102, 128, 154], // v36
    &[6, 28, 54, 80, 106, 132, 158], // v37
    &[6, 32, 58, 84, 110, 136, 162], // v38
    &[6, 26, 54, 82, 110, 138, 166], // v39
    &[6, 30, 58, 86, 114, 142, 170], // v40
];

/// 获取某版本+级别的数据码字容量
fn init_capacity_table() -> [[u16; 4]; 40] {
    let mut table = [[0u16; 4]; 40];
    for v in 1..=40u8 {
        let ver = Version(v);
        let li: [EcLevel; 4] = [EcLevel::L, EcLevel::M, EcLevel::Q, EcLevel::H];
        for (idx, &level) in li.iter().enumerate() {
            let info = ver.ec_info(level);
            let total_data: u16 = info.blocks.iter().map(|b| b.count * b.data_codewords).sum();
            table[v as usize - 1][idx] = total_data;
        }
    }
    table
}

/// 查询指定版本+纠错级别的数据码字容量
///
/// 返回数据码字数（非比特数），乘以 8 得比特容量。
///
/// ```rust
/// use qr_core::version::{get_data_capacity, Version, EcLevel};
///
/// let cap = get_data_capacity(Version(1), EcLevel::M);
/// assert_eq!(cap, 16); // 版本 1-M 有 16 个数据码字
/// ```
// SAFETY: version.0 ∈ [1,40] 由 Version::new() 保证; level 是 4 变体枚举
#[allow(clippy::indexing_slicing)]
pub fn get_data_capacity(version: Version, level: EcLevel) -> u16 {
    static CAPACITY: OnceLock<[[u16; 4]; 40]> = OnceLock::new();
    let cap = CAPACITY.get_or_init(init_capacity_table);
    cap[version.0 as usize - 1][level as usize]
}

/// 自动选择能容纳 `data_bits` 比特的最小版本
///
/// 返回 `None` 表示数据量超出 QR 码最大容量（版本 40）。
///
/// ```rust
/// use qr_core::version::{pick_version, EcLevel};
///
/// let v = pick_version(100, EcLevel::M).unwrap();
/// assert_eq!(v.0, 1); // 版本 1-M 可容纳 16×8=128 bit >= 100
///
/// let too_big = pick_version(50_000, EcLevel::H);
/// assert!(too_big.is_none());
/// ```
pub fn pick_version(data_bits: u16, level: EcLevel) -> Option<Version> {
    for v in 1..=40 {
        let cap_bits = get_data_capacity(Version(v), level) * 8;
        if cap_bits >= data_bits {
            return Some(Version(v));
        }
    }
    None
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_version_size() {
        assert_eq!(Version(1).size(), 21);
        assert_eq!(Version(40).size(), 177);
        assert_eq!(Version(2).size(), 25);
    }

    #[test]
    fn test_version_new_out_of_range() {
        assert!(Version::new(0).is_none());
        assert!(Version::new(41).is_none());
    }

    #[test]
    fn test_pick_version_l() {
        // Version 1 L 级: 19 数据码字 = 152 bits
        let v = pick_version(152, EcLevel::L);
        assert_eq!(v, Some(Version(1)));
    }

    #[test]
    fn test_pick_version_none() {
        // 超过 version 40 容量
        let v = pick_version(30000, EcLevel::H);
        assert!(v.is_none());
    }

    #[test]
    fn test_ec_info_blocks() {
        let info = Version(1).ec_info(EcLevel::M);
        // Version 1 M: 1 block × 16 data codewords, 10 ec per block
        // g2 组 count=0 已被过滤，仅保留 g1
        assert_eq!(info.total_codewords, 26);
        assert_eq!(info.ec_per_block, 10);
        assert_eq!(info.blocks.len(), 1);
        assert_eq!(info.blocks[0].count, 1);
        assert_eq!(info.blocks[0].data_codewords, 16);
    }

    #[test]
    fn test_indicator_bits() {
        assert_eq!(EcLevel::L.indicator_bits(), 0b01);
        assert_eq!(EcLevel::M.indicator_bits(), 0b00);
        assert_eq!(EcLevel::Q.indicator_bits(), 0b11);
        assert_eq!(EcLevel::H.indicator_bits(), 0b10);
    }
}