trustformers-mobile 0.1.1

//! Android RenderScript Legacy Support
//!
//! This module provides RenderScript support for older Android devices that don't
//! support modern compute APIs like Vulkan. RenderScript is deprecated but still
//! widely used for compute tasks on older Android versions.
//!
//! Note: RenderScript was deprecated in Android API 31, but this implementation
//! provides backward compatibility for devices running Android 7.0+ (API 24-30).

use crate::{MobileBackend, MobileConfig, Result};
use serde::{Deserialize, Serialize};
use std::collections::HashMap;
use std::ffi::{CStr, CString};
use std::os::raw::{c_char, c_float, c_int, c_uint, c_void};
use std::ptr;
use std::sync::Arc;
use trustformers_core::{CoreError, Tensor};

/// RenderScript configuration for Android
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct RenderScriptConfig {
    /// Enable RenderScript compute support
    pub enable_compute: bool,
    /// Use RenderScript for matrix operations
    pub matrix_operations: bool,
    /// Use RenderScript for convolutions
    pub convolution_operations: bool,
    /// Use RenderScript for pooling operations
    pub pooling_operations: bool,
    /// Use RenderScript for activation functions
    pub activation_functions: bool,
    /// Maximum work group size
    pub max_work_group_size: u32,
    /// Target API level for compatibility
    pub target_api_level: u32,
    /// Enable performance profiling
    pub enable_profiling: bool,
    /// Memory allocation strategy
    pub allocation_strategy: RSAllocationStrategy,
}

impl Default for RenderScriptConfig {
    fn default() -> Self {
        Self {
            enable_compute: true,
            matrix_operations: true,
            convolution_operations: true,
            pooling_operations: true,
            activation_functions: true,
            max_work_group_size: 1024,
            target_api_level: 24, // Android 7.0
            enable_profiling: false,
            allocation_strategy: RSAllocationStrategy::Shared,
        }
    }
}

/// RenderScript allocation strategies
#[derive(Debug, Clone, Copy, PartialEq, Serialize, Deserialize)]
pub enum RSAllocationStrategy {
    /// Use shared memory allocations
    Shared,
    /// Use graphics surface allocations
    Graphics,
    /// Use usage-specific allocations
    Usage,
}

/// RenderScript kernel types
#[derive(Debug, Clone, Copy, PartialEq, Serialize, Deserialize)]
pub enum RSKernelType {
    /// Matrix multiplication kernel
    MatMul,
    /// 2D Convolution kernel
    Conv2D,
    /// Depthwise convolution kernel
    DepthwiseConv2D,
    /// Max pooling kernel
    MaxPool2D,
    /// Average pooling kernel
    AvgPool2D,
    /// ReLU activation kernel
    ReLU,
    /// Sigmoid activation kernel
    Sigmoid,
    /// Tanh activation kernel
    Tanh,
    /// Element-wise addition kernel
    Add,
    /// Element-wise multiplication kernel
    Mul,
    /// Batch normalization kernel
    BatchNorm,
    /// Softmax kernel
    Softmax,
}

/// Android RenderScript engine
pub struct AndroidRenderScriptEngine {
    config: RenderScriptConfig,
    mobile_config: MobileConfig,
    rs_context: Option<RSContext>,
    compiled_kernels: HashMap<RSKernelType, CompiledKernel>,
    allocation_cache: HashMap<String, RSAllocation>,
    stats: RenderScriptStats,
}

impl AndroidRenderScriptEngine {
    /// Create new RenderScript engine
    pub fn new(config: RenderScriptConfig, mobile_config: MobileConfig) -> Result<Self> {
        let mut engine = Self {
            config,
            mobile_config,
            rs_context: None,
            compiled_kernels: HashMap::new(),
            allocation_cache: HashMap::new(),
            stats: RenderScriptStats::default(),
        };

        // Initialize RenderScript context
        engine.initialize_renderscript()?;

        // Compile essential kernels
        engine.compile_kernels()?;

        Ok(engine)
    }

    /// Initialize RenderScript context
    fn initialize_renderscript(&mut self) -> Result<()> {
        // Check API level compatibility
        if self.config.target_api_level > 30 {
            return Err(TrustformersError::invalid_input(
                "RenderScript is not supported on API level > 30".to_string(),
            )
            .into());
        }

        // Create RenderScript context
        let context = RSContext::create(self.config.target_api_level)?;
        self.rs_context = Some(context);

        self.log_rs_event("RenderScript context initialized");
        Ok(())
    }

    /// Compile RenderScript kernels
    fn compile_kernels(&mut self) -> Result<()> {
        let context = self.rs_context.as_ref().ok_or_else(|| {
            TrustformersError::InvalidState("RenderScript context not initialized".to_string())
        })?;

        // Compile kernels based on configuration
        if self.config.matrix_operations {
            self.compile_kernel(context, RSKernelType::MatMul)?;
        }

        if self.config.convolution_operations {
            self.compile_kernel(context, RSKernelType::Conv2D)?;
            self.compile_kernel(context, RSKernelType::DepthwiseConv2D)?;
        }

        if self.config.pooling_operations {
            self.compile_kernel(context, RSKernelType::MaxPool2D)?;
            self.compile_kernel(context, RSKernelType::AvgPool2D)?;
        }

        if self.config.activation_functions {
            self.compile_kernel(context, RSKernelType::ReLU)?;
            self.compile_kernel(context, RSKernelType::Sigmoid)?;
            self.compile_kernel(context, RSKernelType::Tanh)?;
        }

        // Always compile basic operations
        self.compile_kernel(context, RSKernelType::Add)?;
        self.compile_kernel(context, RSKernelType::Mul)?;
        self.compile_kernel(context, RSKernelType::BatchNorm)?;
        self.compile_kernel(context, RSKernelType::Softmax)?;

        self.log_rs_event(
            &format!(
                "Compiled {} RenderScript kernels",
                self.compiled_kernels.len()
            )
            .into(),
        );
        Ok(())
    }

    /// Compile a specific kernel
    fn compile_kernel(&mut self, context: &RSContext, kernel_type: RSKernelType) -> Result<()> {
        let kernel_source = self.get_kernel_source(kernel_type);
        let compiled = CompiledKernel::compile(context, kernel_type, &kernel_source)?;
        self.compiled_kernels.insert(kernel_type, compiled);
        Ok(())
    }

    /// Get RenderScript kernel source code
    fn get_kernel_source(&self, kernel_type: RSKernelType) -> String {
        match kernel_type {
            RSKernelType::MatMul => r#"
#pragma version(1)
#pragma rs java_package_name(com.trustformers.renderscript)

rs_allocation gInputA;
rs_allocation gInputB;
int gWidthA, gHeightA, gWidthB;

float __attribute__((kernel)) matmul(uint32_t x, uint32_t y) {
    float sum = 0.0f;
    for (int k = 0; k < gWidthA; k++) {
        float a = rsGetElementAt_float(gInputA, k, y);
        float b = rsGetElementAt_float(gInputB, x, k);
        sum += a * b;
    }
    return sum;
}
"#.to_string(),

            RSKernelType::Conv2D => r#"
#pragma version(1)
#pragma rs java_package_name(com.trustformers.renderscript)

rs_allocation gInput;
rs_allocation gKernel;
int gInputWidth, gInputHeight, gKernelSize, gStride, gPadding;

float __attribute__((kernel)) conv2d(uint32_t x, uint32_t y) {
    float sum = 0.0f;
    for (int ky = 0; ky < gKernelSize; ky++) {
        for (int kx = 0; kx < gKernelSize; kx++) {
            int ix = x * gStride + kx - gPadding;
            int iy = y * gStride + ky - gPadding;

            if (ix >= 0 && ix < gInputWidth && iy >= 0 && iy < gInputHeight) {
                float input_val = rsGetElementAt_float(gInput, ix, iy);
                float kernel_val = rsGetElementAt_float(gKernel, kx, ky);
                sum += input_val * kernel_val;
            }
        }
    }
    return sum;
}
"#.to_string(),

            RSKernelType::ReLU => r#"
#pragma version(1)
#pragma rs java_package_name(com.trustformers.renderscript)

float __attribute__((kernel)) relu(float in) {
    return fmax(0.0f, in);
}
"#.to_string(),

            RSKernelType::Sigmoid => r#"
#pragma version(1)
#pragma rs java_package_name(com.trustformers.renderscript)

float __attribute__((kernel)) sigmoid(float in) {
    return 1.0f / (1.0f + exp(-in));
}
"#.to_string(),

            RSKernelType::Tanh => r#"
#pragma version(1)
#pragma rs java_package_name(com.trustformers.renderscript)

float __attribute__((kernel)) tanh_activation(float in) {
    return tanh(in);
}
"#.to_string(),

            RSKernelType::MaxPool2D => r#"
#pragma version(1)
#pragma rs java_package_name(com.trustformers.renderscript)

rs_allocation gInput;
int gInputWidth, gInputHeight, gPoolSize, gStride;

float __attribute__((kernel)) maxpool2d(uint32_t x, uint32_t y) {
    float max_val = -FLT_MAX;
    for (int py = 0; py < gPoolSize; py++) {
        for (int px = 0; px < gPoolSize; px++) {
            int ix = x * gStride + px;
            int iy = y * gStride + py;

            if (ix < gInputWidth && iy < gInputHeight) {
                float val = rsGetElementAt_float(gInput, ix, iy);
                max_val = fmax(max_val, val);
            }
        }
    }
    return max_val;
}
"#.to_string(),

            RSKernelType::AvgPool2D => r#"
#pragma version(1)
#pragma rs java_package_name(com.trustformers.renderscript)

rs_allocation gInput;
int gInputWidth, gInputHeight, gPoolSize, gStride;

float __attribute__((kernel)) avgpool2d(uint32_t x, uint32_t y) {
    float sum = 0.0f;
    int count = 0;
    for (int py = 0; py < gPoolSize; py++) {
        for (int px = 0; px < gPoolSize; px++) {
            int ix = x * gStride + px;
            int iy = y * gStride + py;

            if (ix < gInputWidth && iy < gInputHeight) {
                float val = rsGetElementAt_float(gInput, ix, iy);
                sum += val;
                count++;
            }
        }
    }
    return count > 0 ? sum / count : 0.0f;
}
"#.to_string(),

            RSKernelType::Add => r#"
#pragma version(1)
#pragma rs java_package_name(com.trustformers.renderscript)

float __attribute__((kernel)) add(float a, float b) {
    return a + b;
}
"#.to_string(),

            RSKernelType::Mul => r#"
#pragma version(1)
#pragma rs java_package_name(com.trustformers.renderscript)

float __attribute__((kernel)) mul(float a, float b) {
    return a * b;
}
"#.to_string(),

            RSKernelType::BatchNorm => r#"
#pragma version(1)
#pragma rs java_package_name(com.trustformers.renderscript)

float gMean, gVariance, gGamma, gBeta, gEpsilon;

float __attribute__((kernel)) batchnorm(float in) {
    float normalized = (in - gMean) / sqrt(gVariance + gEpsilon);
    return gGamma * normalized + gBeta;
}
"#.to_string(),

            RSKernelType::Softmax => r#"
#pragma version(1)
#pragma rs java_package_name(com.trustformers.renderscript)

rs_allocation gInput;
float gMaxVal, gSum;
int gSize;

float __attribute__((kernel)) softmax(uint32_t x) {
    float val = rsGetElementAt_float(gInput, x, 0);
    return exp(val - gMaxVal) / gSum;
}
"#.to_string(),

            RSKernelType::DepthwiseConv2D => r#"
#pragma version(1)
#pragma rs java_package_name(com.trustformers.renderscript)

rs_allocation gInput;
rs_allocation gKernel;
int gInputWidth, gInputHeight, gKernelSize, gStride, gPadding, gChannel;

float __attribute__((kernel)) depthwise_conv2d(uint32_t x, uint32_t y) {
    float sum = 0.0f;
    for (int ky = 0; ky < gKernelSize; ky++) {
        for (int kx = 0; kx < gKernelSize; kx++) {
            int ix = x * gStride + kx - gPadding;
            int iy = y * gStride + ky - gPadding;

            if (ix >= 0 && ix < gInputWidth && iy >= 0 && iy < gInputHeight) {
                float input_val = rsGetElementAt_float(gInput, ix + iy * gInputWidth + gChannel * gInputWidth * gInputHeight);
                float kernel_val = rsGetElementAt_float(gKernel, kx + ky * gKernelSize + gChannel * gKernelSize * gKernelSize);
                sum += input_val * kernel_val;
            }
        }
    }
    return sum;
}
"#.to_string(),
        }
    }

    /// Execute RenderScript kernel
    pub fn execute_kernel(
        &mut self,
        kernel_type: RSKernelType,
        inputs: &[&Tensor],
        output_shape: &[usize],
        params: Option<RSKernelParams>,
    ) -> Result<Tensor> {
        let context = self.rs_context.as_ref().ok_or_else(|| {
            TrustformersError::InvalidState("RenderScript context not initialized".to_string())
        })?;

        let kernel = self.compiled_kernels.get(&kernel_type).ok_or_else(|| {
            TrustformersError::InvalidState(format!("Kernel {:?} not compiled", kernel_type))
        })?;

        // Create allocations for inputs and output
        let mut input_allocations = Vec::new();
        for input in inputs {
            let allocation = self.create_allocation(context, input)?;
            input_allocations.push(allocation);
        }

        let output_allocation = self.create_output_allocation(context, output_shape)?;

        // Set kernel parameters
        if let Some(params) = params {
            self.set_kernel_params(kernel, &params)?;
        }

        // Bind input allocations
        for (i, allocation) in input_allocations.iter().enumerate() {
            kernel.bind_allocation(i, allocation)?;
        }

        // Execute kernel
        let launch_params = RSLaunchParams::from_shape(output_shape);
        kernel.launch(&launch_params)?;

        // Copy result back to CPU
        let result = self.allocation_to_tensor(&output_allocation, output_shape)?;

        // Update statistics
        self.stats.total_kernel_executions += 1;
        self.stats
            .kernel_type_counts
            .entry(kernel_type)
            .and_modify(|count| *count += 1)
            .or_insert(1);

        Ok(result)
    }

    /// Create RenderScript allocation from tensor
    fn create_allocation(&mut self, context: &RSContext, tensor: &Tensor) -> Result<RSAllocation> {
        let allocation =
            RSAllocation::create(context, tensor.shape(), self.config.allocation_strategy)?;

        // Copy tensor data to allocation
        allocation.copy_from_tensor(tensor)?;

        Ok(allocation)
    }

    /// Create output allocation
    fn create_output_allocation(
        &self,
        context: &RSContext,
        shape: &[usize],
    ) -> Result<RSAllocation> {
        RSAllocation::create(context, shape, self.config.allocation_strategy)
    }

    /// Set kernel parameters
    fn set_kernel_params(&self, kernel: &CompiledKernel, params: &RSKernelParams) -> Result<()> {
        match params {
            RSKernelParams::Conv2D {
                stride,
                padding,
                kernel_size,
            } => {
                kernel.set_int_param("gStride", *stride as i32)?;
                kernel.set_int_param("gPadding", *padding as i32)?;
                kernel.set_int_param("gKernelSize", *kernel_size as i32)?;
            },
            RSKernelParams::Pool2D { pool_size, stride } => {
                kernel.set_int_param("gPoolSize", *pool_size as i32)?;
                kernel.set_int_param("gStride", *stride as i32)?;
            },
            RSKernelParams::BatchNorm {
                mean,
                variance,
                gamma,
                beta,
                epsilon,
            } => {
                kernel.set_float_param("gMean", *mean)?;
                kernel.set_float_param("gVariance", *variance)?;
                kernel.set_float_param("gGamma", *gamma)?;
                kernel.set_float_param("gBeta", *beta)?;
                kernel.set_float_param("gEpsilon", *epsilon)?;
            },
            RSKernelParams::MatMul {
                width_a,
                height_a,
                width_b,
            } => {
                kernel.set_int_param("gWidthA", *width_a as i32)?;
                kernel.set_int_param("gHeightA", *height_a as i32)?;
                kernel.set_int_param("gWidthB", *width_b as i32)?;
            },
            RSKernelParams::Softmax { max_val, sum } => {
                kernel.set_float_param("gMaxVal", *max_val)?;
                kernel.set_float_param("gSum", *sum)?;
            },
        }
        Ok(())
    }

    /// Convert allocation back to tensor
    fn allocation_to_tensor(&self, allocation: &RSAllocation, shape: &[usize]) -> Result<Tensor> {
        allocation.to_tensor(shape)
    }

    /// Log RenderScript events
    fn log_rs_event(&self, message: &str) {
        if self.config.enable_profiling {
            println!("[RenderScript] {}", message);
        }
    }

    /// Get RenderScript statistics
    pub fn get_stats(&self) -> &RenderScriptStats {
        &self.stats
    }

    /// Check RenderScript availability
    pub fn is_available() -> bool {
        // Check if RenderScript is available on this device
        // This would query the Android system in a real implementation
        true // Placeholder
    }

    /// Get supported API level
    pub fn get_api_level() -> u32 {
        // Get the device's API level
        28 // Placeholder - Android 9.0
    }
}

/// RenderScript context wrapper
struct RSContext {
    context: *mut c_void,
    api_level: u32,
}

impl RSContext {
    fn create(api_level: u32) -> Result<Self> {
        // Create RenderScript context
        // This would call native RenderScript APIs
        Ok(Self {
            context: ptr::null_mut(), // Placeholder
            api_level,
        })
    }
}

/// Compiled RenderScript kernel
struct CompiledKernel {
    script: *mut c_void,
    kernel_type: RSKernelType,
}

impl CompiledKernel {
    fn compile(context: &RSContext, kernel_type: RSKernelType, source: &str) -> Result<Self> {
        // Compile RenderScript kernel from source
        // This would use RenderScript compiler APIs
        Ok(Self {
            script: ptr::null_mut(), // Placeholder
            kernel_type,
        })
    }

    fn bind_allocation(&self, index: usize, allocation: &RSAllocation) -> Result<()> {
        // Bind allocation to kernel parameter
        Ok(())
    }

    fn set_int_param(&self, name: &str, value: i32) -> Result<()> {
        // Set integer parameter
        Ok(())
    }

    fn set_float_param(&self, name: &str, value: f32) -> Result<()> {
        // Set float parameter
        Ok(())
    }

    fn launch(&self, params: &RSLaunchParams) -> Result<()> {
        // Launch kernel execution
        Ok(())
    }
}

/// RenderScript allocation wrapper
struct RSAllocation {
    allocation: *mut c_void,
    shape: Vec<usize>,
}

impl RSAllocation {
    fn create(
        context: &RSContext,
        shape: &[usize],
        strategy: RSAllocationStrategy,
    ) -> Result<Self> {
        // Create RenderScript allocation
        Ok(Self {
            allocation: ptr::null_mut(), // Placeholder
            shape: shape.to_vec(),
        })
    }

    fn copy_from_tensor(&self, tensor: &Tensor) -> Result<()> {
        // Copy tensor data to allocation
        Ok(())
    }

    fn to_tensor(&self, shape: &[usize]) -> Result<Tensor> {
        // Copy allocation data back to tensor
        // Placeholder implementation
        Tensor::zeros(shape, trustformers_core::DType::F32)
    }
}

/// RenderScript launch parameters
struct RSLaunchParams {
    dimensions: Vec<u32>,
}

impl RSLaunchParams {
    fn from_shape(shape: &[usize]) -> Self {
        Self {
            dimensions: shape.iter().map(|&s| s as u32).collect(),
        }
    }
}

/// RenderScript kernel parameters
#[derive(Debug, Clone)]
pub enum RSKernelParams {
    Conv2D {
        stride: usize,
        padding: usize,
        kernel_size: usize,
    },
    Pool2D {
        pool_size: usize,
        stride: usize,
    },
    BatchNorm {
        mean: f32,
        variance: f32,
        gamma: f32,
        beta: f32,
        epsilon: f32,
    },
    MatMul {
        width_a: usize,
        height_a: usize,
        width_b: usize,
    },
    Softmax {
        max_val: f32,
        sum: f32,
    },
}

/// RenderScript statistics
#[derive(Debug, Clone, Default)]
pub struct RenderScriptStats {
    pub total_kernel_executions: usize,
    pub kernel_type_counts: HashMap<RSKernelType, usize>,
    pub total_allocation_count: usize,
    pub peak_memory_usage_mb: f32,
}

impl RenderScriptStats {
    /// Get most used kernel type
    pub fn most_used_kernel(&self) -> Option<RSKernelType> {
        self.kernel_type_counts
            .iter()
            .max_by_key(|(_, &count)| count)
            .map(|(&kernel_type, _)| kernel_type)
    }

    /// Get kernel usage distribution
    pub fn kernel_distribution(&self) -> HashMap<RSKernelType, f32> {
        let total = self.total_kernel_executions as f32;
        if total == 0.0 {
            return HashMap::new();
        }

        self.kernel_type_counts
            .iter()
            .map(|(&kernel_type, &count)| (kernel_type, count as f32 / total))
            .collect()
    }
}

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

    #[test]
    fn test_renderscript_config_default() {
        let config = RenderScriptConfig::default();
        assert!(config.enable_compute);
        assert!(config.matrix_operations);
        assert_eq!(config.target_api_level, 24);
    }

    #[test]
    fn test_renderscript_availability() {
        // Note: This would fail on non-Android platforms
        // In a real implementation, this would properly check platform
        let available = AndroidRenderScriptEngine::is_available();
        // For testing purposes, we just check that the function exists
        let _ = available;
    }

    #[test]
    fn test_renderscript_stats() {
        let mut stats = RenderScriptStats::default();
        stats.total_kernel_executions = 100;
        stats.kernel_type_counts.insert(RSKernelType::Conv2D, 60);
        stats.kernel_type_counts.insert(RSKernelType::ReLU, 40);

        assert_eq!(stats.most_used_kernel(), Some(RSKernelType::Conv2D).into());

        let distribution = stats.kernel_distribution();
        assert_eq!(distribution.get(&RSKernelType::Conv2D), Some(&0.6));
        assert_eq!(distribution.get(&RSKernelType::ReLU), Some(&0.4));
    }

    #[test]
    fn test_kernel_source_generation() {
        let config = RenderScriptConfig::default();
        let mobile_config = MobileConfig::default();

        // This would fail in a real test environment without Android
        // but tests that the engine structure is correct
        let result = AndroidRenderScriptEngine::new(config, mobile_config);
        // We expect this to fail on non-Android platforms
        // In a real implementation, this would be properly mocked
    }
}