// ONNX export functionality
#![allow(unused_variables)] // ONNX export implementation

use super::{ExportConfig, ExportFormat, ExportPrecision, ModelExporter};
use crate::traits::Model;
use anyhow::{anyhow, Result};
use std::collections::HashMap;
use std::fs::File;
use std::io::Write;

/// ONNX model representation
#[derive(Debug)]
pub struct ONNXModel {
    pub graph: ONNXGraph,
    pub ir_version: i64,
    pub opset_imports: Vec<ONNXOpsetImport>,
    pub producer_name: String,
    pub producer_version: String,
    pub model_version: i64,
}

#[derive(Debug)]
pub struct ONNXGraph {
    pub nodes: Vec<ONNXNode>,
    pub inputs: Vec<ONNXValueInfo>,
    pub outputs: Vec<ONNXValueInfo>,
    pub initializers: Vec<ONNXTensor>,
    pub name: String,
}

#[derive(Debug)]
pub struct ONNXNode {
    pub op_type: String,
    pub inputs: Vec<String>,
    pub outputs: Vec<String>,
    pub attributes: HashMap<String, ONNXAttribute>,
    pub name: String,
}

#[derive(Debug)]
pub struct ONNXValueInfo {
    pub name: String,
    pub type_info: ONNXTypeInfo,
}

#[derive(Debug)]
pub struct ONNXTypeInfo {
    pub tensor_type: ONNXTensorType,
}

#[derive(Debug)]
pub struct ONNXTensorType {
    pub elem_type: ONNXDataType,
    pub shape: ONNXTensorShape,
}

#[derive(Debug)]
pub struct ONNXTensorShape {
    pub dims: Vec<ONNXDimension>,
}

#[derive(Debug)]
pub enum ONNXDimension {
    Value(i64),
    Parameter(String),
}

#[derive(Debug, Clone, Copy)]
pub enum ONNXDataType {
    Float = 1,
    UInt8 = 2,
    Int8 = 3,
    UInt16 = 4,
    Int16 = 5,
    Int32 = 6,
    Int64 = 7,
    String = 8,
    Bool = 9,
    Float16 = 10,
    Double = 11,
    UInt32 = 12,
    UInt64 = 13,
    Complex64 = 14,
    Complex128 = 15,
    BFloat16 = 16,
}

#[derive(Debug)]
pub struct ONNXTensor {
    pub name: String,
    pub data_type: ONNXDataType,
    pub dims: Vec<i64>,
    pub raw_data: Vec<u8>,
}

#[derive(Debug)]
pub struct ONNXOpsetImport {
    pub domain: String,
    pub version: i64,
}

#[derive(Debug)]
pub enum ONNXAttribute {
    Int(i64),
    Float(f32),
    String(String),
    Tensor(ONNXTensor),
    Ints(Vec<i64>),
    Floats(Vec<f32>),
    Strings(Vec<String>),
}

/// ONNX operator registry for managing supported operators
#[derive(Debug)]
pub struct ONNXOperatorRegistry {
    pub operators: HashMap<String, ONNXOperatorInfo>,
}

/// Information about an ONNX operator
#[derive(Debug, Clone)]
pub struct ONNXOperatorInfo {
    pub name: String,
    pub opset_version: i64,
    pub inputs: Vec<ONNXOperatorInput>,
    pub outputs: Vec<ONNXOperatorOutput>,
    pub attributes: Vec<ONNXOperatorAttribute>,
    pub description: String,
}

/// Input specification for an ONNX operator
#[derive(Debug, Clone)]
pub struct ONNXOperatorInput {
    pub name: String,
    pub types: Vec<ONNXDataType>,
    pub optional: bool,
    pub description: String,
}

/// Output specification for an ONNX operator
#[derive(Debug, Clone)]
pub struct ONNXOperatorOutput {
    pub name: String,
    pub types: Vec<ONNXDataType>,
    pub description: String,
}

/// Attribute specification for an ONNX operator
#[derive(Debug, Clone)]
pub struct ONNXOperatorAttribute {
    pub name: String,
    pub required: bool,
    pub attribute_type: String,
    pub description: String,
}

/// ONNX exporter implementation
#[derive(Clone)]
pub struct ONNXExporter {
    opset_version: i64,
}

impl Default for ONNXExporter {
    fn default() -> Self {
        Self::new()
    }
}

impl ONNXExporter {
    pub fn new() -> Self {
        Self { opset_version: 14 }
    }

    pub fn with_opset_version(mut self, version: i64) -> Self {
        self.opset_version = version;
        self
    }

    fn create_onnx_model<M: Model>(&self, model: &M, config: &ExportConfig) -> Result<ONNXModel> {
        let mut graph = ONNXGraph {
            nodes: Vec::new(),
            inputs: Vec::new(),
            outputs: Vec::new(),
            initializers: Vec::new(),
            name: "trustformers_model".to_string(),
        };

        // Create input specification
        let batch_size = config.batch_size.unwrap_or(1);
        let seq_len = config.sequence_length.unwrap_or(512);

        let input_ids = ONNXValueInfo {
            name: "input_ids".to_string(),
            type_info: ONNXTypeInfo {
                tensor_type: ONNXTensorType {
                    elem_type: ONNXDataType::Int64,
                    shape: ONNXTensorShape {
                        dims: vec![
                            ONNXDimension::Parameter("batch_size".to_string()),
                            ONNXDimension::Parameter("sequence_length".to_string()),
                        ],
                    },
                },
            },
        };
        graph.inputs.push(input_ids);

        // Create attention mask input
        let attention_mask = ONNXValueInfo {
            name: "attention_mask".to_string(),
            type_info: ONNXTypeInfo {
                tensor_type: ONNXTensorType {
                    elem_type: ONNXDataType::Int64,
                    shape: ONNXTensorShape {
                        dims: vec![
                            ONNXDimension::Parameter("batch_size".to_string()),
                            ONNXDimension::Parameter("sequence_length".to_string()),
                        ],
                    },
                },
            },
        };
        graph.inputs.push(attention_mask);

        // Create output specification
        let output = ONNXValueInfo {
            name: "logits".to_string(),
            type_info: ONNXTypeInfo {
                tensor_type: ONNXTensorType {
                    elem_type: match config.precision {
                        ExportPrecision::FP32 => ONNXDataType::Float,
                        ExportPrecision::FP16 => ONNXDataType::Float16,
                        ExportPrecision::INT8 => ONNXDataType::Int8,
                        ExportPrecision::INT4 => ONNXDataType::Int8, // ONNX doesn't have INT4
                    },
                    shape: ONNXTensorShape {
                        dims: vec![
                            ONNXDimension::Parameter("batch_size".to_string()),
                            ONNXDimension::Parameter("sequence_length".to_string()),
                            ONNXDimension::Value(50257), // Vocab size (example)
                        ],
                    },
                },
            },
        };
        graph.outputs.push(output);

        // Convert model layers to ONNX nodes
        self.convert_model_to_nodes(model, &mut graph, config)?;

        let onnx_model = ONNXModel {
            graph,
            ir_version: 8,
            opset_imports: vec![ONNXOpsetImport {
                domain: "".to_string(),
                version: config.opset_version.unwrap_or(self.opset_version),
            }],
            producer_name: "TrustformeRS".to_string(),
            producer_version: "0.1.0".to_string(),
            model_version: 1,
        };

        Ok(onnx_model)
    }

    fn convert_model_to_nodes<M: Model>(
        &self,
        model: &M,
        graph: &mut ONNXGraph,
        config: &ExportConfig,
    ) -> Result<()> {
        // This is a simplified conversion - in practice, you'd need to:
        // 1. Traverse the model's computational graph
        // 2. Convert each layer to corresponding ONNX operations
        // 3. Handle weight initialization and parameter mapping

        // Example: Add embedding layer
        let embedding_node = ONNXNode {
            op_type: "Gather".to_string(),
            inputs: vec!["embedding_weight".to_string(), "input_ids".to_string()],
            outputs: vec!["embeddings".to_string()],
            attributes: HashMap::new(),
            name: "embedding".to_string(),
        };
        graph.nodes.push(embedding_node);

        // Example: Add transformer layers
        for layer_idx in 0..12 {
            // Assuming 12 layers
            self.add_transformer_layer(graph, layer_idx, config)?;
        }

        // Example: Add final layer norm and linear projection
        let final_norm_node = ONNXNode {
            op_type: "LayerNormalization".to_string(),
            inputs: vec![
                format!("layer_{}_output", 11),
                "final_layer_norm_weight".to_string(),
                "final_layer_norm_bias".to_string(),
            ],
            outputs: vec!["final_hidden_states".to_string()],
            attributes: HashMap::new(),
            name: "final_layer_norm".to_string(),
        };
        graph.nodes.push(final_norm_node);

        let lm_head_node = ONNXNode {
            op_type: "MatMul".to_string(),
            inputs: vec![
                "final_hidden_states".to_string(),
                "lm_head_weight".to_string(),
            ],
            outputs: vec!["logits".to_string()],
            attributes: HashMap::new(),
            name: "lm_head".to_string(),
        };
        graph.nodes.push(lm_head_node);

        Ok(())
    }

    fn add_transformer_layer(
        &self,
        graph: &mut ONNXGraph,
        layer_idx: usize,
        _config: &ExportConfig,
    ) -> Result<()> {
        let layer_prefix = format!("layer_{}", layer_idx);
        let input_name = if layer_idx == 0 {
            "embeddings".to_string()
        } else {
            format!("layer_{}_output", layer_idx - 1)
        };

        // Self-attention layer
        let attention_node = ONNXNode {
            op_type: "MultiHeadAttention".to_string(),
            inputs: vec![
                input_name.clone(),
                input_name.clone(),
                input_name.clone(),
                format!("{}_attention_mask", layer_prefix),
            ],
            outputs: vec![format!("{}_attention_output", layer_prefix)],
            attributes: {
                let mut attrs = HashMap::new();
                attrs.insert("num_heads".to_string(), ONNXAttribute::Int(12));
                attrs
            },
            name: format!("{}_attention", layer_prefix),
        };
        graph.nodes.push(attention_node);

        // Add residual connection
        let add_node = ONNXNode {
            op_type: "Add".to_string(),
            inputs: vec![
                input_name.clone(),
                format!("{}_attention_output", layer_prefix),
            ],
            outputs: vec![format!("{}_attention_residual", layer_prefix)],
            attributes: HashMap::new(),
            name: format!("{}_attention_add", layer_prefix),
        };
        graph.nodes.push(add_node);

        // Layer normalization
        let norm_node = ONNXNode {
            op_type: "LayerNormalization".to_string(),
            inputs: vec![
                format!("{}_attention_residual", layer_prefix),
                format!("{}_norm_weight", layer_prefix),
                format!("{}_norm_bias", layer_prefix),
            ],
            outputs: vec![format!("{}_norm_output", layer_prefix)],
            attributes: HashMap::new(),
            name: format!("{}_norm", layer_prefix),
        };
        graph.nodes.push(norm_node);

        // Feed-forward network
        let ff_node = ONNXNode {
            op_type: "MatMul".to_string(),
            inputs: vec![
                format!("{}_norm_output", layer_prefix),
                format!("{}_ff_weight", layer_prefix),
            ],
            outputs: vec![format!("{}_ff_output", layer_prefix)],
            attributes: HashMap::new(),
            name: format!("{}_feedforward", layer_prefix),
        };
        graph.nodes.push(ff_node);

        // Final residual connection
        let final_add_node = ONNXNode {
            op_type: "Add".to_string(),
            inputs: vec![
                format!("{}_norm_output", layer_prefix),
                format!("{}_ff_output", layer_prefix),
            ],
            outputs: vec![format!("{}_output", layer_prefix)],
            attributes: HashMap::new(),
            name: format!("{}_final_add", layer_prefix),
        };
        graph.nodes.push(final_add_node);

        Ok(())
    }

    fn serialize_onnx_model(&self, model: &ONNXModel, output_path: &str) -> Result<()> {
        // In a real implementation, you would use protobuf to serialize
        // For now, we'll create a simple text representation
        let serialized = self.serialize_to_text(model)?;

        let mut file = File::create(format!("{}.onnx", output_path))?;
        file.write_all(serialized.as_bytes())?;

        Ok(())
    }

    fn serialize_to_text(&self, model: &ONNXModel) -> Result<String> {
        let mut output = String::new();

        output.push_str(&format!("IR Version: {}\n", model.ir_version));
        output.push_str(&format!(
            "Producer: {} {}\n",
            model.producer_name, model.producer_version
        ));
        output.push_str(&format!("Model Version: {}\n", model.model_version));
        output.push('\n');

        output.push_str("Opset Imports:\n");
        for opset in &model.opset_imports {
            output.push_str(&format!(
                "  Domain: '{}', Version: {}\n",
                opset.domain, opset.version
            ));
        }
        output.push('\n');

        output.push_str("Graph:\n");
        output.push_str(&format!("  Name: {}\n", model.graph.name));

        output.push_str("  Inputs:\n");
        for input in &model.graph.inputs {
            output.push_str(&format!("    {}: {:?}\n", input.name, input.type_info));
        }

        output.push_str("  Outputs:\n");
        for output_info in &model.graph.outputs {
            output.push_str(&format!(
                "    {}: {:?}\n",
                output_info.name, output_info.type_info
            ));
        }

        output.push_str("  Nodes:\n");
        for node in &model.graph.nodes {
            output.push_str(&format!(
                "    {} ({}): {} -> {}\n",
                node.name,
                node.op_type,
                node.inputs.join(", "),
                node.outputs.join(", ")
            ));
        }

        Ok(output)
    }
}

impl Default for ONNXOperatorRegistry {
    fn default() -> Self {
        Self::new()
    }
}

impl ONNXOperatorRegistry {
    pub fn new() -> Self {
        Self {
            operators: HashMap::new(),
        }
    }

    pub fn register_all_operators(&mut self) {
        self.register_core_operators();
        self.register_math_operators();
        self.register_neural_network_operators();
        self.register_tensor_operators();
        self.register_control_flow_operators();
        self.register_quantization_operators();
    }

    fn register_core_operators(&mut self) {
        // Core mathematical operations
        self.register_operator(ONNXOperatorInfo {
            name: "Add".to_string(),
            opset_version: 7,
            inputs: vec![
                ONNXOperatorInput {
                    name: "A".to_string(),
                    types: vec![
                        ONNXDataType::Float,
                        ONNXDataType::Double,
                        ONNXDataType::Int32,
                        ONNXDataType::Int64,
                    ],
                    optional: false,
                    description: "First operand".to_string(),
                },
                ONNXOperatorInput {
                    name: "B".to_string(),
                    types: vec![
                        ONNXDataType::Float,
                        ONNXDataType::Double,
                        ONNXDataType::Int32,
                        ONNXDataType::Int64,
                    ],
                    optional: false,
                    description: "Second operand".to_string(),
                },
            ],
            outputs: vec![ONNXOperatorOutput {
                name: "C".to_string(),
                types: vec![
                    ONNXDataType::Float,
                    ONNXDataType::Double,
                    ONNXDataType::Int32,
                    ONNXDataType::Int64,
                ],
                description: "Result of addition".to_string(),
            }],
            attributes: vec![],
            description: "Element-wise addition".to_string(),
        });

        self.register_operator(ONNXOperatorInfo {
            name: "MatMul".to_string(),
            opset_version: 1,
            inputs: vec![
                ONNXOperatorInput {
                    name: "A".to_string(),
                    types: vec![
                        ONNXDataType::Float,
                        ONNXDataType::Double,
                        ONNXDataType::Float16,
                        ONNXDataType::BFloat16,
                    ],
                    optional: false,
                    description: "N-dimensional matrix A".to_string(),
                },
                ONNXOperatorInput {
                    name: "B".to_string(),
                    types: vec![
                        ONNXDataType::Float,
                        ONNXDataType::Double,
                        ONNXDataType::Float16,
                        ONNXDataType::BFloat16,
                    ],
                    optional: false,
                    description: "N-dimensional matrix B".to_string(),
                },
            ],
            outputs: vec![ONNXOperatorOutput {
                name: "Y".to_string(),
                types: vec![
                    ONNXDataType::Float,
                    ONNXDataType::Double,
                    ONNXDataType::Float16,
                    ONNXDataType::BFloat16,
                ],
                description: "Matrix multiplication result".to_string(),
            }],
            attributes: vec![],
            description: "Matrix multiplication".to_string(),
        });
    }

    fn register_math_operators(&mut self) {
        // Activation functions
        let activations = vec![
            ("Relu", "Rectified Linear Unit activation"),
            ("Sigmoid", "Sigmoid activation function"),
            ("Tanh", "Hyperbolic tangent activation"),
            ("Gelu", "Gaussian Error Linear Unit activation"),
            ("LeakyRelu", "Leaky ReLU activation"),
            ("Elu", "Exponential Linear Unit activation"),
            ("Selu", "Scaled Exponential Linear Unit activation"),
            ("Swish", "Swish activation function"),
        ];

        for (name, desc) in activations {
            self.register_operator(ONNXOperatorInfo {
                name: name.to_string(),
                opset_version: 6,
                inputs: vec![ONNXOperatorInput {
                    name: "X".to_string(),
                    types: vec![
                        ONNXDataType::Float,
                        ONNXDataType::Double,
                        ONNXDataType::Float16,
                    ],
                    optional: false,
                    description: "Input tensor".to_string(),
                }],
                outputs: vec![ONNXOperatorOutput {
                    name: "Y".to_string(),
                    types: vec![
                        ONNXDataType::Float,
                        ONNXDataType::Double,
                        ONNXDataType::Float16,
                    ],
                    description: "Output tensor".to_string(),
                }],
                attributes: if name == "LeakyRelu" {
                    vec![ONNXOperatorAttribute {
                        name: "alpha".to_string(),
                        attribute_type: "float".to_string(),
                        required: false,
                        description: "Coefficient of leakage".to_string(),
                    }]
                } else {
                    vec![]
                },
                description: desc.to_string(),
            });
        }

        // Mathematical functions
        let math_ops = vec![
            "Abs",
            "Acos",
            "Asin",
            "Atan",
            "Ceil",
            "Cos",
            "Cosh",
            "Exp",
            "Floor",
            "Log",
            "Neg",
            "Reciprocal",
            "Round",
            "Sign",
            "Sin",
            "Sinh",
            "Sqrt",
            "Tan",
            "Erf",
        ];

        for op in math_ops {
            self.register_operator(ONNXOperatorInfo {
                name: op.to_string(),
                opset_version: 6,
                inputs: vec![ONNXOperatorInput {
                    name: "input".to_string(),
                    types: vec![
                        ONNXDataType::Float,
                        ONNXDataType::Double,
                        ONNXDataType::Float16,
                    ],
                    optional: false,
                    description: "Input tensor".to_string(),
                }],
                outputs: vec![ONNXOperatorOutput {
                    name: "output".to_string(),
                    types: vec![
                        ONNXDataType::Float,
                        ONNXDataType::Double,
                        ONNXDataType::Float16,
                    ],
                    description: "Output tensor".to_string(),
                }],
                attributes: vec![],
                description: format!("{} mathematical function", op),
            });
        }
    }

    fn register_neural_network_operators(&mut self) {
        // Convolution
        self.register_operator(ONNXOperatorInfo {
            name: "Conv".to_string(),
            opset_version: 11,
            inputs: vec![
                ONNXOperatorInput {
                    name: "X".to_string(),
                    types: vec![
                        ONNXDataType::Float,
                        ONNXDataType::Double,
                        ONNXDataType::Float16,
                    ],
                    optional: false,
                    description: "Input data tensor".to_string(),
                },
                ONNXOperatorInput {
                    name: "W".to_string(),
                    types: vec![
                        ONNXDataType::Float,
                        ONNXDataType::Double,
                        ONNXDataType::Float16,
                    ],
                    optional: false,
                    description: "Weight tensor".to_string(),
                },
                ONNXOperatorInput {
                    name: "B".to_string(),
                    types: vec![
                        ONNXDataType::Float,
                        ONNXDataType::Double,
                        ONNXDataType::Float16,
                    ],
                    optional: true,
                    description: "Optional bias tensor".to_string(),
                },
            ],
            outputs: vec![ONNXOperatorOutput {
                name: "Y".to_string(),
                types: vec![
                    ONNXDataType::Float,
                    ONNXDataType::Double,
                    ONNXDataType::Float16,
                ],
                description: "Output data tensor".to_string(),
            }],
            attributes: vec![
                ONNXOperatorAttribute {
                    name: "strides".to_string(),
                    attribute_type: "ints".to_string(),
                    required: false,
                    description: "Stride along each spatial axis".to_string(),
                },
                ONNXOperatorAttribute {
                    name: "pads".to_string(),
                    attribute_type: "ints".to_string(),
                    required: false,
                    description: "Padding for the beginning and ending".to_string(),
                },
                ONNXOperatorAttribute {
                    name: "dilations".to_string(),
                    attribute_type: "ints".to_string(),
                    required: false,
                    description: "Dilation value along each spatial axis".to_string(),
                },
                ONNXOperatorAttribute {
                    name: "group".to_string(),
                    attribute_type: "int".to_string(),
                    required: false,
                    description:
                        "Number of groups input channels and output channels are divided into"
                            .to_string(),
                },
            ],
            description: "Convolution operator".to_string(),
        });

        // Batch Normalization
        self.register_operator(ONNXOperatorInfo {
            name: "BatchNormalization".to_string(),
            opset_version: 15,
            inputs: vec![
                ONNXOperatorInput {
                    name: "X".to_string(),
                    types: vec![
                        ONNXDataType::Float,
                        ONNXDataType::Double,
                        ONNXDataType::Float16,
                    ],
                    optional: false,
                    description: "Input tensor".to_string(),
                },
                ONNXOperatorInput {
                    name: "scale".to_string(),
                    types: vec![
                        ONNXDataType::Float,
                        ONNXDataType::Double,
                        ONNXDataType::Float16,
                    ],
                    optional: false,
                    description: "Scale tensor".to_string(),
                },
                ONNXOperatorInput {
                    name: "B".to_string(),
                    types: vec![
                        ONNXDataType::Float,
                        ONNXDataType::Double,
                        ONNXDataType::Float16,
                    ],
                    optional: false,
                    description: "Bias tensor".to_string(),
                },
                ONNXOperatorInput {
                    name: "input_mean".to_string(),
                    types: vec![
                        ONNXDataType::Float,
                        ONNXDataType::Double,
                        ONNXDataType::Float16,
                    ],
                    optional: false,
                    description: "Running mean".to_string(),
                },
                ONNXOperatorInput {
                    name: "input_var".to_string(),
                    types: vec![
                        ONNXDataType::Float,
                        ONNXDataType::Double,
                        ONNXDataType::Float16,
                    ],
                    optional: false,
                    description: "Running variance".to_string(),
                },
            ],
            outputs: vec![ONNXOperatorOutput {
                name: "Y".to_string(),
                types: vec![
                    ONNXDataType::Float,
                    ONNXDataType::Double,
                    ONNXDataType::Float16,
                ],
                description: "Output tensor".to_string(),
            }],
            attributes: vec![ONNXOperatorAttribute {
                name: "epsilon".to_string(),
                attribute_type: "float".to_string(),
                required: false,
                description: "Small constant to avoid division by zero".to_string(),
            }],
            description: "Batch normalization operator".to_string(),
        });
    }

    fn register_tensor_operators(&mut self) {
        // Tensor shape manipulation
        let shape_ops = vec![
            ("Reshape", "Reshape the input tensor"),
            ("Transpose", "Transpose the input tensor"),
            ("Squeeze", "Remove single-dimensional entries"),
            ("Unsqueeze", "Insert single-dimensional entries"),
            ("Flatten", "Flatten the input tensor"),
        ];

        for (name, desc) in shape_ops {
            self.register_operator(ONNXOperatorInfo {
                name: name.to_string(),
                opset_version: 13,
                inputs: if name == "Reshape" {
                    vec![
                        ONNXOperatorInput {
                            name: "data".to_string(),
                            types: vec![
                                ONNXDataType::Float,
                                ONNXDataType::Double,
                                ONNXDataType::Int32,
                                ONNXDataType::Int64,
                            ],
                            optional: false,
                            description: "Input tensor".to_string(),
                        },
                        ONNXOperatorInput {
                            name: "shape".to_string(),
                            types: vec![ONNXDataType::Int64],
                            optional: false,
                            description: "New shape".to_string(),
                        },
                    ]
                } else {
                    vec![ONNXOperatorInput {
                        name: "data".to_string(),
                        types: vec![
                            ONNXDataType::Float,
                            ONNXDataType::Double,
                            ONNXDataType::Int32,
                            ONNXDataType::Int64,
                        ],
                        optional: false,
                        description: "Input tensor".to_string(),
                    }]
                },
                outputs: vec![ONNXOperatorOutput {
                    name: "reshaped".to_string(),
                    types: vec![
                        ONNXDataType::Float,
                        ONNXDataType::Double,
                        ONNXDataType::Int32,
                        ONNXDataType::Int64,
                    ],
                    description: "Reshaped tensor".to_string(),
                }],
                attributes: match name {
                    "Transpose" => vec![ONNXOperatorAttribute {
                        name: "perm".to_string(),
                        attribute_type: "ints".to_string(),
                        required: false,
                        description: "A list of integers. By default, reverse the dimensions"
                            .to_string(),
                    }],
                    "Flatten" => vec![ONNXOperatorAttribute {
                        name: "axis".to_string(),
                        attribute_type: "int".to_string(),
                        required: false,
                        description: "Indicate which axis to flatten".to_string(),
                    }],
                    _ => vec![],
                },
                description: desc.to_string(),
            });
        }

        // Reduction operations
        let reduce_ops = vec![
            "ReduceSum",
            "ReduceMean",
            "ReduceMax",
            "ReduceMin",
            "ReduceProd",
            "ReduceL1",
            "ReduceL2",
            "ReduceLogSum",
            "ReduceLogSumExp",
            "ReduceSumSquare",
        ];

        for op in reduce_ops {
            self.register_operator(ONNXOperatorInfo {
                name: op.to_string(),
                opset_version: 13,
                inputs: vec![ONNXOperatorInput {
                    name: "data".to_string(),
                    types: vec![
                        ONNXDataType::Float,
                        ONNXDataType::Double,
                        ONNXDataType::Int32,
                        ONNXDataType::Int64,
                    ],
                    optional: false,
                    description: "Input tensor".to_string(),
                }],
                outputs: vec![ONNXOperatorOutput {
                    name: "reduced".to_string(),
                    types: vec![
                        ONNXDataType::Float,
                        ONNXDataType::Double,
                        ONNXDataType::Int32,
                        ONNXDataType::Int64,
                    ],
                    description: "Reduced tensor".to_string(),
                }],
                attributes: vec![
                    ONNXOperatorAttribute {
                        name: "axes".to_string(),
                        attribute_type: "ints".to_string(),
                        required: false,
                        description: "A list of integers, along which to reduce".to_string(),
                    },
                    ONNXOperatorAttribute {
                        name: "keepdims".to_string(),
                        attribute_type: "int".to_string(),
                        required: false,
                        description: "Keep the reduced dimension or not".to_string(),
                    },
                ],
                description: format!("{} reduction operation", op),
            });
        }
    }

    fn register_control_flow_operators(&mut self) {
        // Control flow operations
        self.register_operator(ONNXOperatorInfo {
            name: "If".to_string(),
            opset_version: 11,
            inputs: vec![ONNXOperatorInput {
                name: "cond".to_string(),
                types: vec![ONNXDataType::Bool],
                optional: false,
                description: "Condition tensor".to_string(),
            }],
            outputs: vec![ONNXOperatorOutput {
                name: "outputs".to_string(),
                types: vec![
                    ONNXDataType::Float,
                    ONNXDataType::Double,
                    ONNXDataType::Int32,
                    ONNXDataType::Int64,
                ],
                description: "Output values".to_string(),
            }],
            attributes: vec![
                ONNXOperatorAttribute {
                    name: "then_branch".to_string(),
                    attribute_type: "string".to_string(),
                    required: true,
                    description: "Graph to run if condition is true".to_string(),
                },
                ONNXOperatorAttribute {
                    name: "else_branch".to_string(),
                    attribute_type: "string".to_string(),
                    required: true,
                    description: "Graph to run if condition is false".to_string(),
                },
            ],
            description: "Conditional execution".to_string(),
        });

        self.register_operator(ONNXOperatorInfo {
            name: "Loop".to_string(),
            opset_version: 13,
            inputs: vec![
                ONNXOperatorInput {
                    name: "M".to_string(),
                    types: vec![ONNXDataType::Int64],
                    optional: true,
                    description: "Maximum trip count".to_string(),
                },
                ONNXOperatorInput {
                    name: "cond".to_string(),
                    types: vec![ONNXDataType::Bool],
                    optional: true,
                    description: "Loop termination condition".to_string(),
                },
            ],
            outputs: vec![ONNXOperatorOutput {
                name: "v_final".to_string(),
                types: vec![
                    ONNXDataType::Float,
                    ONNXDataType::Double,
                    ONNXDataType::Int32,
                    ONNXDataType::Int64,
                ],
                description: "Final loop carried values".to_string(),
            }],
            attributes: vec![ONNXOperatorAttribute {
                name: "body".to_string(),
                attribute_type: "string".to_string(),
                required: true,
                description: "Graph to execute in the loop".to_string(),
            }],
            description: "Loop execution".to_string(),
        });
    }

    fn register_quantization_operators(&mut self) {
        // Quantization operations
        self.register_operator(ONNXOperatorInfo {
            name: "QuantizeLinear".to_string(),
            opset_version: 13,
            inputs: vec![
                ONNXOperatorInput {
                    name: "x".to_string(),
                    types: vec![ONNXDataType::Float, ONNXDataType::Int32],
                    optional: false,
                    description: "Input tensor".to_string(),
                },
                ONNXOperatorInput {
                    name: "y_scale".to_string(),
                    types: vec![ONNXDataType::Float],
                    optional: false,
                    description: "Scale for doing quantization".to_string(),
                },
                ONNXOperatorInput {
                    name: "y_zero_point".to_string(),
                    types: vec![ONNXDataType::UInt8, ONNXDataType::Int8],
                    optional: true,
                    description: "Zero point for quantization".to_string(),
                },
            ],
            outputs: vec![ONNXOperatorOutput {
                name: "y".to_string(),
                types: vec![ONNXDataType::UInt8, ONNXDataType::Int8],
                description: "Quantized output tensor".to_string(),
            }],
            attributes: vec![],
            description: "Linear quantization operator".to_string(),
        });

        self.register_operator(ONNXOperatorInfo {
            name: "DequantizeLinear".to_string(),
            opset_version: 13,
            inputs: vec![
                ONNXOperatorInput {
                    name: "x".to_string(),
                    types: vec![ONNXDataType::UInt8, ONNXDataType::Int8],
                    optional: false,
                    description: "Quantized input tensor".to_string(),
                },
                ONNXOperatorInput {
                    name: "x_scale".to_string(),
                    types: vec![ONNXDataType::Float],
                    optional: false,
                    description: "Scale for doing dequantization".to_string(),
                },
                ONNXOperatorInput {
                    name: "x_zero_point".to_string(),
                    types: vec![ONNXDataType::UInt8, ONNXDataType::Int8],
                    optional: true,
                    description: "Zero point for dequantization".to_string(),
                },
            ],
            outputs: vec![ONNXOperatorOutput {
                name: "y".to_string(),
                types: vec![ONNXDataType::Float],
                description: "Dequantized output tensor".to_string(),
            }],
            attributes: vec![],
            description: "Linear dequantization operator".to_string(),
        });
    }

    fn register_operator(&mut self, operator_info: ONNXOperatorInfo) {
        self.operators.insert(operator_info.name.clone(), operator_info);
    }

    pub fn get_operator_names(&self) -> Vec<String> {
        self.operators.keys().cloned().collect()
    }

    pub fn has_operator(&self, name: &str) -> bool {
        self.operators.contains_key(name)
    }

    pub fn get_operator(&self, name: &str) -> Option<&ONNXOperatorInfo> {
        self.operators.get(name)
    }

    pub fn get_operators_by_opset(&self, opset_version: i64) -> Vec<&ONNXOperatorInfo> {
        self.operators.values().filter(|op| op.opset_version <= opset_version).collect()
    }

    pub fn validate_operator_usage(
        &self,
        op_name: &str,
        inputs: &[String],
        attributes: &HashMap<String, ONNXAttribute>,
    ) -> Result<()> {
        let op_info = self
            .get_operator(op_name)
            .ok_or_else(|| anyhow!("Unsupported operator: {}", op_name))?;

        // Check required inputs
        let required_inputs = op_info.inputs.iter().filter(|input| !input.optional).count();

        if inputs.len() < required_inputs {
            return Err(anyhow!(
                "Operator {} requires at least {} inputs, got {}",
                op_name,
                required_inputs,
                inputs.len()
            ));
        }

        // Check required attributes
        for attr in &op_info.attributes {
            if attr.required && !attributes.contains_key(&attr.name) {
                return Err(anyhow!(
                    "Operator {} requires attribute '{}'",
                    op_name,
                    attr.name
                ));
            }
        }

        Ok(())
    }
}

impl ModelExporter for ONNXExporter {
    fn export<M: Model>(&self, model: &M, config: &ExportConfig) -> Result<()> {
        if config.format != ExportFormat::ONNX {
            return Err(anyhow!("ONNXExporter only supports ONNX format"));
        }

        let onnx_model = self.create_onnx_model(model, config)?;
        self.serialize_onnx_model(&onnx_model, &config.output_path)?;

        println!("Model exported to {}.onnx", config.output_path);
        Ok(())
    }

    fn supported_formats(&self) -> Vec<ExportFormat> {
        vec![ExportFormat::ONNX]
    }

    fn validate_model<M: Model>(&self, _model: &M, format: ExportFormat) -> Result<()> {
        if format != ExportFormat::ONNX {
            return Err(anyhow!("ONNXExporter only supports ONNX format"));
        }
        Ok(())
    }
}

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

    #[test]
    fn test_onnx_exporter_creation() {
        let exporter = ONNXExporter::new();
        assert_eq!(exporter.opset_version, 14);

        let exporter_v13 = exporter.with_opset_version(13);
        assert_eq!(exporter_v13.opset_version, 13);
    }

    #[test]
    fn test_onnx_data_types() {
        assert_eq!(ONNXDataType::Float as i64, 1);
        assert_eq!(ONNXDataType::Float16 as i64, 10);
        assert_eq!(ONNXDataType::Int64 as i64, 7);
    }

    #[test]
    fn test_supported_formats() {
        let exporter = ONNXExporter::new();
        let formats = exporter.supported_formats();
        assert_eq!(formats.len(), 1);
        assert_eq!(formats[0], ExportFormat::ONNX);
    }

    #[test]
    fn test_onnx_dimension_types() {
        let dim_value = ONNXDimension::Value(512);
        let dim_param = ONNXDimension::Parameter("batch_size".to_string());

        match dim_value {
            ONNXDimension::Value(v) => assert_eq!(v, 512),
            _ => panic!("Expected Value dimension"),
        }

        match dim_param {
            ONNXDimension::Parameter(p) => assert_eq!(p, "batch_size"),
            _ => panic!("Expected Parameter dimension"),
        }
    }

    #[test]
    fn test_onnx_attribute_types() {
        let int_attr = ONNXAttribute::Int(42);
        let float_attr = ONNXAttribute::Float(std::f32::consts::PI);
        let string_attr = ONNXAttribute::String("test".to_string());

        match int_attr {
            ONNXAttribute::Int(v) => assert_eq!(v, 42),
            _ => panic!("Expected Int attribute"),
        }

        match float_attr {
            ONNXAttribute::Float(v) => assert!((v - std::f32::consts::PI).abs() < 1e-6),
            _ => panic!("Expected Float attribute"),
        }

        match string_attr {
            ONNXAttribute::String(s) => assert_eq!(s, "test"),
            _ => panic!("Expected String attribute"),
        }
    }
}
