// 模型名称映射
use std::collections::HashMap;
use once_cell::sync::Lazy;
use dashmap::DashMap;

// 动态官方废弃模型转发表 (old_model_id -> new_model_id)
pub static DYNAMIC_MODEL_FORWARDING_RULES: Lazy<DashMap<String, String>> = Lazy::new(|| DashMap::new());

pub fn update_dynamic_forwarding_rules(old_model: String, new_model: String) {
    if !DYNAMIC_MODEL_FORWARDING_RULES.contains_key(&old_model) {
        crate::modules::logger::log_info(&format!("[Mapping] Registered automatic forwarding rule: {} -> {}", old_model, new_model));
    }
    DYNAMIC_MODEL_FORWARDING_RULES.insert(old_model, new_model);
}

static CLAUDE_TO_GEMINI: Lazy<HashMap<&'static str, &'static str>> = Lazy::new(|| {
    let mut m = HashMap::new();

    // 直接支持的模型
    m.insert("claude-sonnet-4-6", "claude-sonnet-4-6");
    m.insert("claude-sonnet-4-6-thinking", "claude-sonnet-4-6-thinking");

    // [Redirect] Sonnet 4.5 -> Sonnet 4.6
    m.insert("claude-sonnet-4-5", "claude-sonnet-4-6");
    m.insert("claude-sonnet-4-5-thinking", "claude-sonnet-4-6-thinking");

    // 别名映射
    m.insert("claude-sonnet-4-5-20250929", "claude-sonnet-4-6-thinking");
    m.insert("claude-3-5-sonnet-20241022", "claude-sonnet-4-6");
    m.insert("claude-3-5-sonnet-20240620", "claude-sonnet-4-6");
    // [Redirect] Opus 4.5 -> Opus 4.6 (Issue #1743)
    m.insert("claude-opus-4", "claude-opus-4-6-thinking");
    m.insert("claude-opus-4-5-thinking", "claude-opus-4-6-thinking");
    m.insert("claude-opus-4-5-20251101", "claude-opus-4-6-thinking");

    // Claude Opus 4.6
    m.insert("claude-opus-4-6-thinking", "claude-opus-4-6-thinking");
    m.insert("claude-opus-4-6", "claude-opus-4-6-thinking");
    m.insert("claude-opus-4-6-20260201", "claude-opus-4-6-thinking");

    m.insert("claude-haiku-4", "claude-sonnet-4-6");
    m.insert("claude-3-haiku-20240307", "claude-sonnet-4-6");
    m.insert("claude-haiku-4-5-20251001", "claude-sonnet-4-6");
    // OpenAI 协议映射表
    m.insert("gpt-4", "gemini-2.5-flash");
    m.insert("gpt-4-turbo", "gemini-2.5-flash");
    m.insert("gpt-4-turbo-preview", "gemini-2.5-flash");
    m.insert("gpt-4-0125-preview", "gemini-2.5-flash");
    m.insert("gpt-4-1106-preview", "gemini-2.5-flash");
    m.insert("gpt-4-0613", "gemini-2.5-flash");

    m.insert("gpt-4o", "gemini-2.5-flash");
    m.insert("gpt-4o-2024-05-13", "gemini-2.5-flash");
    m.insert("gpt-4o-2024-08-06", "gemini-2.5-flash");

    m.insert("gpt-4o-mini", "gemini-2.5-flash");
    m.insert("gpt-4o-mini-2024-07-18", "gemini-2.5-flash");

    m.insert("gpt-3.5-turbo", "gemini-2.5-flash");
    m.insert("gpt-3.5-turbo-16k", "gemini-2.5-flash");
    m.insert("gpt-3.5-turbo-0125", "gemini-2.5-flash");
    m.insert("gpt-3.5-turbo-1106", "gemini-2.5-flash");
    m.insert("gpt-3.5-turbo-0613", "gemini-2.5-flash");

    // Gemini 协议映射表
    m.insert("gemini-2.5-flash-lite", "gemini-2.5-flash");
    m.insert("gemini-2.5-flash-thinking", "gemini-2.5-flash-thinking");
    // Gemini Pro family:
    // - Concrete model IDs should pass through unchanged.
    // - Generic aliases (without tier) still route to preview as fallback entrypoint.
    m.insert("gemini-3.1-pro-low", "gemini-3.1-pro-low");
    m.insert("gemini-3.1-pro-high", "gemini-3.1-pro-high");
    m.insert("gemini-3.1-pro-preview", "gemini-3.1-pro-preview");
    m.insert("gemini-3.1-pro", "gemini-3.1-pro-preview");
    m.insert("gemini-3-pro-low", "gemini-3-pro-low");
    m.insert("gemini-3-pro-high", "gemini-3-pro-high");
    m.insert("gemini-3-pro-preview", "gemini-3-pro-preview");
    m.insert("gemini-3-pro", "gemini-3-pro-preview");
    m.insert("gemini-2.5-flash", "gemini-2.5-flash");
    m.insert("gemini-3-flash", "gemini-3-flash");
    m.insert("gemini-3-pro-image", "gemini-3-pro-image");

    // [New] Unified Virtual ID for Background Tasks (Title, Summary, etc.)
    // Allows users to override all background tasks via custom_mapping
    m.insert("internal-background-task", "gemini-2.5-flash");


    m
});


/// Map Claude model names to Gemini model names
/// 
/// # 映射策略
/// 1. **精确匹配**: 检查 CLAUDE_TO_GEMINI 映射表
/// 2. **已知前缀透传**: gemini-* 和 *-thinking 模型直接透传
/// 3. **[NEW] 直接透传**: 未知模型 ID 直接传递给 Google API (支持体验未发布模型)
/// 
/// # 参数
/// - `input`: 原始模型名称
/// 
/// # 返回
/// 映射后的目标模型名称
/// 
/// # 示例
/// ```
/// // 精确匹配
/// assert_eq!(map_claude_model_to_gemini("claude-opus-4"), "claude-opus-4-5-thinking");
/// 
/// // Gemini 模型透传
/// assert_eq!(map_claude_model_to_gemini("gemini-2.5-flash"), "gemini-2.5-flash");
/// 
/// // 直接透传未知模型 (NEW!)
/// assert_eq!(map_claude_model_to_gemini("claude-opus-4-6"), "claude-opus-4-6");
/// assert_eq!(map_claude_model_to_gemini("claude-sonnet-5"), "claude-sonnet-5");
/// ```
pub fn map_claude_model_to_gemini(input: &str) -> String {
    // 1. Check exact match in map
    if let Some(mapped) = CLAUDE_TO_GEMINI.get(input) {
        return mapped.to_string();
    }

    // 2. Pass-through known prefixes (gemini-, -thinking) to support dynamic suffixes
    if input.starts_with("gemini-") || input.contains("thinking") {
        return input.to_string();
    }


    // 3. [ENHANCED] 直接透传未知模型 ID,而不是强制 fallback
    // 这允许用户通过自定义映射体验未发布的模型 (如 claude-opus-4-6)
    // Google API 会自动处理无效模型并返回错误,用户可以根据错误调整映射
    input.to_string()
}

/// 获取所有内置支持的模型列表关键字
pub fn get_supported_models() -> Vec<String> {
    CLAUDE_TO_GEMINI.keys().map(|s| s.to_string()).collect()
}

/// 动态获取所有可用模型列表 (包含内置与用户自定义与官方端点动态下发)
pub async fn get_all_dynamic_models(
    custom_mapping: &tokio::sync::RwLock<std::collections::HashMap<String, String>>,
    token_manager: Option<&crate::proxy::token_manager::TokenManager>,
) -> Vec<String> {
    use std::collections::HashSet;
    let mut model_ids = HashSet::new();

    // 1. 获取所有内置映射模型
    for m in get_supported_models() {
        model_ids.insert(m);
    }

    // 2. 获取所有自定义映射模型 (Custom)
    {
        let mapping = custom_mapping.read().await;
        for key in mapping.keys() {
            model_ids.insert(key.clone());
        }
    }

    // 3. [NEW] 获取所有账号从官方接口汇聚而来的动态模型
    if let Some(tm) = token_manager {
        for dynamic_model in tm.get_all_collected_models() {
            model_ids.insert(dynamic_model);
        }
    }

    // 5. 确保包含常用的 Gemini/画画模型 ID
    model_ids.insert("gemini-3.1-pro-low".to_string());
    
    // [NEW] Issue #247: Dynamically generate all Image Gen Combinations
    let base = "gemini-3-pro-image";
    let resolutions = vec!["", "-2k", "-4k"];
    let ratios = vec!["", "-1x1", "-4x3", "-3x4", "-16x9", "-9x16", "-21x9"];
    
    for res in resolutions {
        for ratio in ratios.iter() {
            let mut id = base.to_string();
            id.push_str(res);
            id.push_str(ratio);
            model_ids.insert(id);
        }
    }

    model_ids.insert("gemini-2.0-flash-exp".to_string());
    model_ids.insert("gemini-2.5-flash".to_string());
    // gemini-2.5-pro removed 
    model_ids.insert("gemini-3-flash".to_string());
    model_ids.insert("gemini-3.1-pro-high".to_string());
    model_ids.insert("gemini-3.1-pro-low".to_string());


    let mut sorted_ids: Vec<_> = model_ids.into_iter().collect();
    sorted_ids.sort();
    sorted_ids
}

/// Wildcard matching - supports multiple wildcards
///
/// **Note**: Matching is **case-sensitive**. Pattern `GPT-4*` will NOT match `gpt-4-turbo`.
///
/// Examples:
/// - `gpt-4*` matches `gpt-4`, `gpt-4-turbo` ✓
/// - `claude-*-sonnet-*` matches `claude-3-5-sonnet-20241022` ✓
/// - `*-thinking` matches `claude-opus-4-5-thinking` ✓
/// - `a*b*c` matches `a123b456c` ✓
fn wildcard_match(pattern: &str, text: &str) -> bool {
    let parts: Vec<&str> = pattern.split('*').collect();

    // No wildcard - exact match
    if parts.len() == 1 {
        return pattern == text;
    }

    let mut text_pos = 0;

    for (i, part) in parts.iter().enumerate() {
        if part.is_empty() {
            continue; // Skip empty segments from consecutive wildcards
        }

        if i == 0 {
            // First segment must match start
            if !text[text_pos..].starts_with(part) {
                return false;
            }
            text_pos += part.len();
        } else if i == parts.len() - 1 {
            // Last segment must match end
            return text[text_pos..].ends_with(part);
        } else {
            // Middle segments - find next occurrence
            if let Some(pos) = text[text_pos..].find(part) {
                text_pos += pos + part.len();
            } else {
                return false;
            }
        }
    }

    true
}

/// 核心模型路由解析引擎
/// 优先级：精确匹配 > 通配符匹配 > 系统默认映射
/// 
/// # 参数
/// - `original_model`: 原始模型名称
/// - `custom_mapping`: 用户自定义映射表
/// 
/// # 返回
/// 映射后的目标模型名称
pub fn resolve_model_route(
    original_model: &str,
    custom_mapping: &std::collections::HashMap<String, String>,
) -> String {
    // 0. API 热更新废弃模型转发 (最高物理优先级，强制纠正)
    // 如果用户非要用已经被移除的模型，并且官方下发了 fallback path，我们在此拦截并纠正
    if let Some(forwarded) = DYNAMIC_MODEL_FORWARDING_RULES.get(original_model) {
        crate::modules::logger::log_info(&format!("[Router] 官方淘汰重定向: {} -> {}", original_model, forwarded.value()));
        return forwarded.value().clone();
    }

    // 1. 精确匹配 (次高优先级)
    if let Some(target) = custom_mapping.get(original_model) {
        crate::modules::logger::log_info(&format!("[Router] 精确映射: {} -> {}", original_model, target));
        return target.clone();
    }
    
    // 2. Wildcard match - most specific (highest non-wildcard chars) wins
    // Note: When multiple patterns have the SAME specificity, HashMap iteration order
    // determines the result (non-deterministic). Users can avoid this by making patterns
    // more specific. Future improvement: use IndexMap + frontend sorting for full control.
    let mut best_match: Option<(&str, &str, usize)> = None;

    for (pattern, target) in custom_mapping.iter() {
        if pattern.contains('*') && wildcard_match(pattern, original_model) {
            let specificity = pattern.chars().count() - pattern.matches('*').count();
            if best_match.is_none() || specificity > best_match.unwrap().2 {
                best_match = Some((pattern.as_str(), target.as_str(), specificity));
            }
        }
    }

    if let Some((pattern, target, _)) = best_match {
        crate::modules::logger::log_info(&format!(
            "[Router] Wildcard match: {} -> {} (rule: {})",
            original_model, target, pattern
        ));
        return target.to_string();
    }
    
    // 3. 系统默认映射
    let result = map_claude_model_to_gemini(original_model);
    if result != original_model {
        crate::modules::logger::log_info(&format!("[Router] 系统默认映射: {} -> {}", original_model, result));
    }
    result
}

/// Normalize any physical model name to one of the 3 standard protection IDs.
/// This ensures quota protection works consistently regardless of API versioning or request variations.
/// 
/// Standard IDs:
/// - `gemini-3-flash`: All Flash variants (1.5-flash, 2.5-flash, 3-flash, etc.)
/// - `gemini-3-pro-high`: All Pro variants (1.5-pro, 2.5-pro, etc.)
/// - `claude-sonnet-4-5`: All Claude Sonnet variants (3-5-sonnet, sonnet-4-5, etc.)
/// 
/// Returns `None` if the model doesn't match any of the 3 protected categories.
pub fn normalize_to_standard_id(model_name: &str) -> Option<String> {
    let lower = model_name.to_lowercase();
    
    // 1. image 资源 (优先匹配，使用 contains 匹配以支持任何变体，如 gemini-3.1-flash-image)
    if lower.contains("image") {
        return Some("gemini-3-pro-image".to_string());
    }

    // 2. gemini-3-flash (包含所有 flash 变体)
    if lower.contains("flash") {
        return Some("gemini-3-flash".to_string());
    }

    // 3. gemini-3-pro-high (包含 pro 变体)
    if lower.contains("pro") && !lower.contains("image") {
        return Some("gemini-3-pro-high".to_string());
    }

    // 4. Claude 系列 (合并 Opus, Sonnet, Haiku 为统一保护组 'claude')
    if lower.contains("claude") || lower.contains("opus") || lower.contains("sonnet") || lower.contains("haiku") {
        return Some("claude".to_string());
    }

    None
}

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

    #[test]
    fn test_model_mapping() {
        assert_eq!(
            map_claude_model_to_gemini("claude-3-5-sonnet-20241022"),
            "claude-sonnet-4-6"
        );
        // [Redirect] Sonnet 4.5 -> Sonnet 4.6
        assert_eq!(
            map_claude_model_to_gemini("claude-sonnet-4-5"),
            "claude-sonnet-4-6"
        );
        assert_eq!(
            map_claude_model_to_gemini("claude-sonnet-4-5-thinking"),
            "claude-sonnet-4-6-thinking"
        );
        assert_eq!(
            map_claude_model_to_gemini("claude-opus-4"),
            "claude-opus-4-6-thinking"
        );
        // Test gemini pass-through (should not be caught by "mini" rule)
        assert_eq!(
            map_claude_model_to_gemini("gemini-2.5-flash-mini-test"),
            "gemini-2.5-flash-mini-test"
        );
        assert_eq!(map_claude_model_to_gemini("unknown-model"), "unknown-model");
        // Gemini Pro concrete IDs should pass through unchanged.
        assert_eq!(
            map_claude_model_to_gemini("gemini-3-pro-high"),
            "gemini-3-pro-high"
        );
        assert_eq!(
            map_claude_model_to_gemini("gemini-3-pro-low"),
            "gemini-3-pro-low"
        );
        assert_eq!(
            map_claude_model_to_gemini("gemini-3.1-pro-high"),
            "gemini-3.1-pro-high"
        );
        assert_eq!(
            map_claude_model_to_gemini("gemini-3.1-pro-low"),
            "gemini-3.1-pro-low"
        );
        // Generic aliases still map to preview entrypoint.
        assert_eq!(
            map_claude_model_to_gemini("gemini-3-pro"),
            "gemini-3-pro-preview"
        );
        assert_eq!(
            map_claude_model_to_gemini("gemini-3.1-pro"),
            "gemini-3.1-pro-preview"
        );

        // Test Normalization (Opus 4.6 now merged into "claude" group)
        assert_eq!(normalize_to_standard_id("claude-opus-4-6-thinking"), Some("claude".to_string()));
        assert_eq!(
            normalize_to_standard_id("claude-sonnet-4-5"),
            Some("claude".to_string())
        );

        // [Regression] gemini-3-pro-image must NOT be grouped with gemini-3-pro-high
        assert_eq!(
            normalize_to_standard_id("gemini-3-pro-image"),
            Some("gemini-3-pro-image".to_string())
        );
        assert_eq!(
            normalize_to_standard_id("gemini-3-pro-high"),
            Some("gemini-3-pro-high".to_string())
        );

        // [FIX #1955] Test normalization with image suffixes
        assert_eq!(
            normalize_to_standard_id("gemini-3-pro-image-4k"),
            Some("gemini-3-pro-image".to_string())
        );
        assert_eq!(
            normalize_to_standard_id("gemini-3-pro-image-16x9"),
            Some("gemini-3-pro-image".to_string())
        );
        assert_eq!(
            normalize_to_standard_id("gemini-3-pro-image-4k-16x9"),
            Some("gemini-3-pro-image".to_string())
        );
        assert_eq!(
            normalize_to_standard_id("gemini-3.1-flash-image"),
            Some("gemini-3-pro-image".to_string())
        );
        assert_eq!(
            normalize_to_standard_id("gemini-3.1-flash-image-4k"),
            Some("gemini-3-pro-image".to_string())
        );
    }

    #[test]
    fn test_wildcard_priority() {
        let mut custom = HashMap::new();
        custom.insert("gpt*".to_string(), "fallback".to_string());
        custom.insert("gpt-4*".to_string(), "specific".to_string());
        custom.insert("claude-opus-*".to_string(), "opus-default".to_string());
        custom.insert("claude-opus*thinking".to_string(), "opus-thinking".to_string());

        // More specific pattern wins
        assert_eq!(resolve_model_route("gpt-4-turbo", &custom), "specific");
        assert_eq!(resolve_model_route("gpt-3.5", &custom), "fallback");
        // Suffix constraint is more specific than prefix-only
        assert_eq!(resolve_model_route("claude-opus-4-5-thinking", &custom), "opus-thinking");
        assert_eq!(resolve_model_route("claude-opus-4", &custom), "opus-default");
    }

    #[test]
    fn test_multi_wildcard_support() {
        let mut custom = HashMap::new();
        custom.insert("claude-*-sonnet-*".to_string(), "sonnet-versioned".to_string());
        custom.insert("gpt-*-*".to_string(), "gpt-multi".to_string());
        custom.insert("*thinking*".to_string(), "has-thinking".to_string());

        // Multi-wildcard patterns should work
        assert_eq!(
            resolve_model_route("claude-3-5-sonnet-20241022", &custom),
            "sonnet-versioned"
        );
        assert_eq!(
            resolve_model_route("gpt-4-turbo-preview", &custom),
            "gpt-multi"
        );
        assert_eq!(
            resolve_model_route("claude-thinking-extended", &custom),
            "has-thinking"
        );

        // Negative case: *thinking* should NOT match models without "thinking"
        assert_eq!(
            resolve_model_route("random-model-name", &custom),
            "random-model-name"  // Falls back to system default (pass-through)
        );
    }

    #[test]
    fn test_wildcard_edge_cases() {
        let mut custom = HashMap::new();
        custom.insert("prefix*".to_string(), "prefix-match".to_string());
        custom.insert("*".to_string(), "catch-all".to_string());
        custom.insert("a*b*c".to_string(), "multi-wild".to_string());

        // Specificity: "prefix*" (6) > "*" (0)
        assert_eq!(resolve_model_route("prefix-anything", &custom), "prefix-match");
        // Catch-all has lowest specificity
        assert_eq!(resolve_model_route("random-model", &custom), "catch-all");
        // Multi-wildcard: "a*b*c" (3)
        assert_eq!(resolve_model_route("a-test-b-foo-c", &custom), "multi-wild");
    }
}