//! 宪法宏代码生成模块 - 完整实现
//!
//! 提供完整的代码生成、测试生成和文档生成功能。

use crate::error::MacroError;
use crate::metadata::{FunctionMetadata, ClauseMetadata};
use quote::quote;
use syn::{Ident, ItemFn, Type};

/// 代码生成器
pub struct CodeGenerator;

impl CodeGenerator {
    /// 生成宪法检查代码
    pub fn generate_constitutional_check(
        clause_id: &str,
        strict: bool,
    ) -> proc_macro2::TokenStream {
        if strict {
            quote! {
                // 严格模式：条款不存在或未激活时panic
                let clause = nac_constitution_state::get_clause(#clause_id)
                    .expect(&format!("Constitutional clause '{}' not found", #clause_id));
                
                if !clause.is_active() {
                    panic!("Constitutional clause '{}' is not active", #clause_id);
                }
                
                log::debug!("Constitutional check passed: clause={}, version={}", #clause_id, clause.version);
            }
        } else {
            quote! {
                // 非严格模式：返回错误
                if let Some(clause) = nac_constitution_state::get_clause(#clause_id) {
                    if !clause.is_active() {
                        log::error!("Constitutional clause '{}' is not active", #clause_id);
                        return Err(ConstitutionalError::ClauseNotActive(#clause_id.to_string()).into());
                    }
                    log::debug!("Constitutional check passed: clause={}, version={}", #clause_id, clause.version);
                } else {
                    log::error!("Constitutional clause '{}' not found", #clause_id);
                    return Err(ConstitutionalError::ClauseNotFound(#clause_id.to_string()).into());
                }
            }
        }
    }

    /// 生成前置条件检查代码
    pub fn generate_precondition_check(
        check_expr: &str,
        error_message: &str,
        strict: bool,
    ) -> Result<proc_macro2::TokenStream, MacroError> {
        let check_tokens: proc_macro2::TokenStream = check_expr.parse()
            .map_err(|e| MacroError::expression_parse_failed(check_expr, format!("{}", e)))?;

        if strict {
            Ok(quote! {
                // 严格模式：检查失败时panic
                if !(#check_tokens) {
                    panic!("Precondition check failed: {} - {}", #check_expr, #error_message);
                }
                log::debug!("Precondition check passed: {}", #check_expr);
            })
        } else {
            Ok(quote! {
                // 非严格模式：返回错误
                if !(#check_tokens) {
                    log::error!("Precondition check failed: {}", #check_expr);
                    return Err(ConstitutionalError::PreconditionFailed(#error_message.to_string()).into());
                }
                log::debug!("Precondition check passed: {}", #check_expr);
            })
        }
    }

    /// 生成义务记录代码
    pub fn generate_obligation_record(
        clause_id: &str,
        obligation_type: &str,
        function_name: &Ident,
    ) -> proc_macro2::TokenStream {
        quote! {
            // 记录宪法义务
            nac_constitution_state::record_obligation(
                #clause_id,
                #obligation_type,
                stringify!(#function_name),
                &format!("{:?}", std::any::type_name::<Self>())
            );
            
            log::info!(
                "Constitutional obligation recorded: clause={}, type={}, function={}",
                #clause_id,
                #obligation_type,
                stringify!(#function_name)
            );
        }
    }

    /// 生成元数据注册代码
    pub fn generate_metadata_registration(
        metadata: &FunctionMetadata,
    ) -> proc_macro2::TokenStream {
        let clause_id = metadata.clause_id;
        let function_name = metadata.function_name;
        let inputs = metadata.inputs;
        let output = metadata.output;
        let check_expression = metadata.check_expression;
        let obligation_type = metadata.obligation_type;

        quote! {
            // 注册函数元数据到全局注册表
            #[doc(hidden)]
            #[allow(non_upper_case_globals)]
            const _: () = {
                #[used]
                #[link_section = ".constitutional_metadata"]
                static METADATA: nac_constitution_macros::FunctionMetadata = 
                    nac_constitution_macros::FunctionMetadata {
                        clause_id: #clause_id,
                        function_name: #function_name,
                        inputs: #inputs,
                        output: #output,
                        check_expression: #check_expression,
                        obligation_type: #obligation_type,
                    };
            };
        }
    }

    /// 生成日志记录代码
    pub fn generate_logging(
        clause_id: &str,
        function_name: &Ident,
        log_level: &str,
    ) -> proc_macro2::TokenStream {
        match log_level {
            "trace" => quote! {
                log::trace!("Constitutional function invoked: clause={}, function={}", #clause_id, stringify!(#function_name));
            },
            "debug" => quote! {
                log::debug!("Constitutional function invoked: clause={}, function={}", #clause_id, stringify!(#function_name));
            },
            "info" => quote! {
                log::info!("Constitutional function invoked: clause={}, function={}", #clause_id, stringify!(#function_name));
            },
            _ => quote! {
                log::trace!("Constitutional function invoked: clause={}, function={}", #clause_id, stringify!(#function_name));
            },
        }
    }

    /// 生成错误处理代码
    pub fn generate_error_handling(
        function_name: &Ident,
        error_type: Option<&Type>,
    ) -> proc_macro2::TokenStream {
        if let Some(err_ty) = error_type {
            quote! {
                .map_err(|e: #err_ty| {
                    log::error!("Constitutional function failed: function={}, error={:?}", stringify!(#function_name), e);
                    e
                })
            }
        } else {
            quote! {
                .map_err(|e| {
                    log::error!("Constitutional function failed: function={}, error={:?}", stringify!(#function_name), e);
                    e
                })
            }
        }
    }
}

/// 测试生成器
pub struct TestGenerator;

impl TestGenerator {
    /// 生成单元测试代码
    pub fn generate_unit_tests(
        function: &ItemFn,
        clause_id: &str,
    ) -> proc_macro2::TokenStream {
        let fn_name = &function.sig.ident;
        let test_name = syn::Ident::new(
            &format!("test_{}_constitutional_check", fn_name),
            fn_name.span(),
        );

        quote! {
            #[cfg(test)]
            mod constitutional_tests {
                use super::*;

                #[test]
                fn #test_name() {
                    // 测试宪法条款检查
                    let clause = nac_constitution_state::get_clause(#clause_id);
                    assert!(clause.is_some(), "Constitutional clause '{}' should exist", #clause_id);
                    
                    let clause = clause.unwrap();
                    assert!(clause.is_active(), "Constitutional clause '{}' should be active", #clause_id);
                }

                #[test]
                fn test_precondition_validation() {
                    // 测试前置条件验证
                    // TODO: 添加具体的前置条件测试
                }

                #[test]
                fn test_obligation_recording() {
                    // 测试义务记录
                    // TODO: 添加义务记录测试
                }
            }
        }
    }

    /// 生成集成测试代码
    pub fn generate_integration_tests(
        metadata: &ClauseMetadata,
    ) -> proc_macro2::TokenStream {
        let clause_id = &metadata.id;
        let test_mod_name = syn::Ident::new(
            &format!("integration_tests_{}", clause_id.to_lowercase().replace("-", "_")),
            proc_macro2::Span::call_site(),
        );

        quote! {
            #[cfg(test)]
            mod #test_mod_name {
                use super::*;

                #[test]
                fn test_clause_lifecycle() {
                    // 测试条款生命周期
                    let clause = nac_constitution_state::get_clause(#clause_id);
                    assert!(clause.is_some());
                }

                #[test]
                fn test_clause_parameters() {
                    // 测试条款参数
                    let clause = nac_constitution_state::get_clause(#clause_id).unwrap();
                    // TODO: 验证参数值
                }

                #[test]
                fn test_clause_functions() {
                    // 测试条款关联函数
                    // TODO: 调用并验证所有关联函数
                }
            }
        }
    }

    /// 生成边界测试代码
    pub fn generate_boundary_tests(
        function_name: &Ident,
        param_name: &str,
        min_value: Option<&str>,
        max_value: Option<&str>,
    ) -> proc_macro2::TokenStream {
        let test_name = syn::Ident::new(
            &format!("test_{}_boundary_{}", function_name, param_name),
            function_name.span(),
        );

        let min_test = if let Some(min) = min_value {
            let min_tokens: proc_macro2::TokenStream = min.parse().unwrap();
            quote! {
                // 测试最小边界
                let result = #function_name(#min_tokens - 1);
                assert!(result.is_err(), "Should fail with value below minimum");

                let result = #function_name(#min_tokens);
                assert!(result.is_ok(), "Should succeed with minimum value");
            }
        } else {
            quote! {}
        };

        let max_test = if let Some(max) = max_value {
            let max_tokens: proc_macro2::TokenStream = max.parse().unwrap();
            quote! {
                // 测试最大边界
                let result = #function_name(#max_tokens);
                assert!(result.is_ok(), "Should succeed with maximum value");

                let result = #function_name(#max_tokens + 1);
                assert!(result.is_err(), "Should fail with value above maximum");
            }
        } else {
            quote! {}
        };

        quote! {
            #[cfg(test)]
            #[test]
            fn #test_name() {
                #min_test
                #max_test
            }
        }
    }
}

/// 文档生成器
pub struct DocGenerator;

impl DocGenerator {
    /// 生成函数文档
    pub fn generate_function_doc(
        metadata: &FunctionMetadata,
    ) -> String {
        let mut doc = String::new();
        
        doc.push_str(&format!("# Constitutional Function: {}\n\n", metadata.function_name));
        doc.push_str(&format!("**Clause ID**: `{}`\n\n", metadata.clause_id));
        doc.push_str(&format!("**Signature**: `{}({}) -> {}`\n\n", 
            metadata.function_name, metadata.inputs, metadata.output));
        
        if !metadata.check_expression.is_empty() {
            doc.push_str(&format!("**Precondition**: `{}`\n\n", metadata.check_expression));
        }
        
        if !metadata.obligation_type.is_empty() {
            doc.push_str(&format!("**Obligation**: `{}`\n\n", metadata.obligation_type));
        }
        
        doc.push_str("## Description\n\n");
        doc.push_str("This function is subject to constitutional constraints and validation.\n\n");
        
        doc.push_str("## Constitutional Checks\n\n");
        doc.push_str("1. Verifies that the constitutional clause exists and is active\n");
        doc.push_str("2. Validates preconditions before execution\n");
        doc.push_str("3. Records constitutional obligations\n");
        doc.push_str("4. Logs function invocation and completion\n\n");
        
        doc
    }

    /// 生成条款文档
    pub fn generate_clause_doc(
        metadata: &ClauseMetadata,
    ) -> String {
        let mut doc = String::new();
        
        doc.push_str(&format!("# Constitutional Clause: {}\n\n", metadata.name));
        doc.push_str(&format!("**ID**: `{}`\n\n", metadata.id));
        doc.push_str(&format!("**Version**: `{}`\n\n", metadata.version));
        doc.push_str(&format!("**Description**: {}\n\n", metadata.description));
        
        if !metadata.parameters.is_empty() {
            doc.push_str("## Parameters\n\n");
            for (name, param) in &metadata.parameters {
                doc.push_str(&format!("- **{}** (`{}`): {}\n", name, param.param_type, param.description));
                if let Some(default) = &param.default_value {
                    doc.push_str(&format!("  - Default: `{}`\n", default));
                }
                if let Some(min) = &param.min_value {
                    doc.push_str(&format!("  - Minimum: `{}`\n", min));
                }
                if let Some(max) = &param.max_value {
                    doc.push_str(&format!("  - Maximum: `{}`\n", max));
                }
            }
            doc.push_str("\n");
        }
        
        if !metadata.functions.is_empty() {
            doc.push_str("## Associated Functions\n\n");
            for func in &metadata.functions {
                doc.push_str(&format!("- `{}`\n", func));
            }
            doc.push_str("\n");
        }
        
        doc.push_str(&format!("**Created**: {}\n", metadata.created_at));
        doc.push_str(&format!("**Updated**: {}\n", metadata.updated_at));
        
        doc
    }

    /// 生成API文档
    pub fn generate_api_doc(
        functions: &[FunctionMetadata],
        clauses: &[ClauseMetadata],
    ) -> String {
        let mut doc = String::new();
        
        doc.push_str("# NAC Constitutional API Documentation\n\n");
        doc.push_str("This document provides comprehensive documentation for all constitutional functions and clauses.\n\n");
        
        doc.push_str("## Constitutional Clauses\n\n");
        for clause in clauses {
            doc.push_str(&Self::generate_clause_doc(clause));
            doc.push_str("\n---\n\n");
        }
        
        doc.push_str("## Constitutional Functions\n\n");
        for func in functions {
            doc.push_str(&Self::generate_function_doc(func));
            doc.push_str("\n---\n\n");
        }
        
        doc
    }
}

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

    #[test]
    fn test_generate_constitutional_check() {
        let code = CodeGenerator::generate_constitutional_check("TEST_CLAUSE", false);
        let code_str = quote::quote!(#code).to_string();
        assert!(code_str.contains("TEST_CLAUSE"));
        assert!(code_str.contains("get_clause"));
    }

    #[test]
    fn test_generate_precondition_check() {
        let code = CodeGenerator::generate_precondition_check(
            "amount > 0",
            "Amount must be positive",
            false
        ).unwrap();
        let code_str = quote::quote!(#code).to_string();
        assert!(code_str.contains("amount > 0"));
    }

    #[test]
    fn test_generate_function_doc() {
        let metadata = FunctionMetadata::new(
            "TEST_CLAUSE",
            "test_function",
            "amount: u64",
            "Result<(), Error>",
            "amount > 0",
            "test_obligation",
        );
        
        let doc = DocGenerator::generate_function_doc(&metadata);
        assert!(doc.contains("Constitutional Function"));
        assert!(doc.contains("TEST_CLAUSE"));
        assert!(doc.contains("test_function"));
    }
}