#![cfg(feature = "normalized_dev")]

use crate::config::env::joinir_dev_enabled;
use crate::mir::join_ir::normalized::dev_env;
use crate::mir::join_ir::{JoinFuncId, JoinFunction, JoinInst, JoinModule};

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub(crate) enum NormalizedDevShape {
    Pattern1Mini,
    Pattern2Mini,
    JsonparserSkipWsMini,
    JsonparserSkipWsReal,
    JsonparserAtoiMini,
    JsonparserAtoiReal,
    JsonparserParseNumberReal,
}

type Detector = fn(&JoinModule) -> bool;

const SHAPE_DETECTORS: &[(NormalizedDevShape, Detector)] = &[
    (NormalizedDevShape::Pattern1Mini, detectors::is_pattern1_mini),
    (NormalizedDevShape::Pattern2Mini, detectors::is_pattern2_mini),
    (
        NormalizedDevShape::JsonparserSkipWsMini,
        detectors::is_jsonparser_skip_ws_mini,
    ),
    (
        NormalizedDevShape::JsonparserSkipWsReal,
        detectors::is_jsonparser_skip_ws_real,
    ),
    (
        NormalizedDevShape::JsonparserAtoiMini,
        detectors::is_jsonparser_atoi_mini,
    ),
    (
        NormalizedDevShape::JsonparserAtoiReal,
        detectors::is_jsonparser_atoi_real,
    ),
    (
        NormalizedDevShape::JsonparserParseNumberReal,
        detectors::is_jsonparser_parse_number_real,
    ),
];

/// direct ブリッジで扱う shape（dev 限定）。
pub(crate) fn direct_shapes(module: &JoinModule) -> Vec<NormalizedDevShape> {
    let shapes = detect_shapes(module);
    log_shapes("direct", &shapes);
    shapes
}

/// Structured→Normalized の対象 shape（dev 限定）。
pub(crate) fn supported_shapes(module: &JoinModule) -> Vec<NormalizedDevShape> {
    let shapes = detect_shapes(module);
    log_shapes("roundtrip", &shapes);
    shapes
}

/// canonical（常時 Normalized 経路を通す）対象。
/// Phase 41: P2 コアセット（P2 mini + JP skip_ws mini/real + JP atoi mini）。
pub(crate) fn canonical_shapes(module: &JoinModule) -> Vec<NormalizedDevShape> {
    let shapes: Vec<_> = detect_shapes(module)
        .into_iter()
        .filter(|s| {
            matches!(
                s,
                NormalizedDevShape::Pattern2Mini
                    | NormalizedDevShape::JsonparserSkipWsMini
                    | NormalizedDevShape::JsonparserSkipWsReal
                    | NormalizedDevShape::JsonparserAtoiMini
            )
        })
        .collect();
    log_shapes("canonical", &shapes);
    shapes
}

#[allow(dead_code)]
pub(crate) fn is_direct_supported(module: &JoinModule) -> bool {
    !detect_shapes(module).is_empty()
}

fn detect_shapes(module: &JoinModule) -> Vec<NormalizedDevShape> {
    let mut shapes: Vec<_> = SHAPE_DETECTORS
        .iter()
        .filter_map(|(shape, detector)| if detector(module) { Some(*shape) } else { None })
        .collect();

    // Pattern1 は「最小の後方互換」なので、より具体的な shape が見つかった場合は外しておく。
    if shapes.len() > 1 {
        shapes.retain(|s| *s != NormalizedDevShape::Pattern1Mini);
    }

    shapes
}

// --- 判定ロジック（共通） ---
mod detectors {
    use super::*;

    pub(super) fn is_pattern1_mini(module: &JoinModule) -> bool {
        module.is_structured() && find_loop_step(module).is_some()
    }

    pub(super) fn is_pattern2_mini(module: &JoinModule) -> bool {
        if !module.is_structured() || module.functions.len() != 3 {
            return false;
        }
        let loop_func = match find_loop_step(module) {
            Some(f) => f,
            None => return false,
        };
        if !(1..=3).contains(&loop_func.params.len()) {
            return false;
        }

        let has_cond_jump = loop_func
            .body
            .iter()
            .any(|inst| matches!(inst, JoinInst::Jump { cond: Some(_), .. }));
        let has_tail_call = loop_func
            .body
            .iter()
            .any(|inst| matches!(inst, JoinInst::Call { k_next: None, .. }));

        has_cond_jump && has_tail_call
    }

    pub(super) fn is_jsonparser_skip_ws_mini(module: &JoinModule) -> bool {
        is_pattern2_mini(module)
            && module
                .functions
                .values()
                .any(|f| f.name == "jsonparser_skip_ws_mini")
    }

    pub(crate) fn is_jsonparser_skip_ws_real(module: &JoinModule) -> bool {
        if !module.is_structured() || module.functions.len() != 3 {
            return false;
        }
        let loop_func = match find_loop_step(module) {
            Some(f) => f,
            None => return false,
        };
        if !(2..=6).contains(&loop_func.params.len()) {
            return false;
        }

        let has_cond_jump = loop_func
            .body
            .iter()
            .any(|inst| matches!(inst, JoinInst::Jump { cond: Some(_), .. }));
        let has_tail_call = loop_func
            .body
            .iter()
            .any(|inst| matches!(inst, JoinInst::Call { k_next: None, .. }));

        has_cond_jump
            && has_tail_call
            && module
                .functions
                .values()
                .any(|f| f.name == "jsonparser_skip_ws_real")
    }

    pub(crate) fn is_jsonparser_atoi_mini(module: &JoinModule) -> bool {
        if !module.is_structured() || module.functions.len() != 3 {
            return false;
        }
        let loop_func = match find_loop_step(module) {
            Some(f) => f,
            None => return false,
        };
        if !(3..=8).contains(&loop_func.params.len()) {
            return false;
        }

        let has_cond_jump = loop_func
            .body
            .iter()
            .any(|inst| matches!(inst, JoinInst::Jump { cond: Some(_), .. }));
        let has_tail_call = loop_func
            .body
            .iter()
            .any(|inst| matches!(inst, JoinInst::Call { k_next: None, .. }));

        has_cond_jump
            && has_tail_call
            && module
                .functions
                .values()
                .any(|f| f.name == "jsonparser_atoi_mini")
    }

    pub(crate) fn is_jsonparser_atoi_real(module: &JoinModule) -> bool {
        if !module.is_structured() || module.functions.len() != 3 {
            return false;
        }
        let loop_func = match find_loop_step(module) {
            Some(f) => f,
            None => return false,
        };
        if !(3..=10).contains(&loop_func.params.len()) {
            return false;
        }

        let has_cond_jump = loop_func
            .body
            .iter()
            .any(|inst| matches!(inst, JoinInst::Jump { cond: Some(_), .. }));
        let has_tail_call = loop_func
            .body
            .iter()
            .any(|inst| matches!(inst, JoinInst::Call { k_next: None, .. }));

        has_cond_jump
            && has_tail_call
            && module
                .functions
                .values()
                .any(|f| f.name == "jsonparser_atoi_real")
    }

    pub(crate) fn is_jsonparser_parse_number_real(module: &JoinModule) -> bool {
        if !module.is_structured() || module.functions.len() != 3 {
            return false;
        }
        let loop_func = match find_loop_step(module) {
            Some(f) => f,
            None => return false,
        };
        if !(3..=12).contains(&loop_func.params.len()) {
            return false;
        }

        let has_cond_jump = loop_func
            .body
            .iter()
            .any(|inst| matches!(inst, JoinInst::Jump { cond: Some(_), .. }));
        let has_tail_call = loop_func
            .body
            .iter()
            .any(|inst| matches!(inst, JoinInst::Call { k_next: None, .. }));

        has_cond_jump
            && has_tail_call
            && module
                .functions
                .values()
                .any(|f| f.name == "jsonparser_parse_number_real")
    }

    pub(super) fn find_loop_step(module: &JoinModule) -> Option<&JoinFunction> {
        module
            .functions
            .values()
            .find(|f| f.name == "loop_step")
            .or_else(|| module.functions.get(&JoinFuncId::new(1)))
    }
}

fn log_shapes(tag: &str, shapes: &[NormalizedDevShape]) {
    if shapes.is_empty() {
        return;
    }
    if dev_env::normalized_dev_logs_enabled() && joinir_dev_enabled() {
        eprintln!("[joinir/normalized-dev/shape] {}: {:?}", tag, shapes);
    }
}