use log::*;
use std::io::Write;
use std::process::{Command, Stdio, Child};
use which::which;

use crate::meta_plugin::{MetaPlugin, MetaPluginResponse, MetaPluginType};

pub struct MetaPluginExec {
    pub program: String,
    pub args: Vec<String>,
    pub supported: bool,
    pub split_whitespace: bool,
    process: Option<Child>,
    writer: Option<Box<dyn Write>>,
    result: Option<String>,
    outputs: std::collections::HashMap<String, serde_yaml::Value>,
    options: std::collections::HashMap<String, serde_yaml::Value>,
}

// Manual Debug implementation because Box<dyn Write> doesn't implement Debug
impl std::fmt::Debug for MetaPluginExec {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.debug_struct("MetaPluginExec")
            .field("program", &self.program)
            .field("args", &self.args)
            .field("supported", &self.supported)
            .field("split_whitespace", &self.split_whitespace)
            .field("process", &self.process)
            .field("writer", &self.writer.as_ref().map(|_| "Box<dyn Write>"))
            .field("result", &self.result)
            .field("outputs", &self.outputs)
            .field("options", &self.options)
            .finish()
    }
}


impl MetaPluginExec {
    pub fn new(
        program: &str, 
        args: Vec<&str>, 
        meta_name: String, 
        split_whitespace: bool,
        _options: Option<std::collections::HashMap<String, serde_yaml::Value>>,
        outputs: Option<std::collections::HashMap<String, serde_yaml::Value>>,
    ) -> MetaPluginExec {
        let program_path = which(program);
        let supported = program_path.is_ok();
        
        // Start with default outputs
        let mut final_outputs = std::collections::HashMap::new();
        final_outputs.insert(meta_name.clone(), serde_yaml::Value::String(meta_name.clone()));
        if let Some(outs) = outputs {
            for (key, value) in outs {
                final_outputs.insert(key, value);
            }
        }

        // Start with default options
        let mut final_options = std::collections::HashMap::new();
        if let Some(opts) = _options {
            for (key, value) in opts {
                final_options.insert(key, value);
            }
        }
        
        MetaPluginExec {
            program: program_path.map_or_else(|_| program.to_string(), |p| p.to_string_lossy().to_string()),
            args: args.iter().map(|s| s.to_string()).collect(),
            supported,
            split_whitespace,
            process: None,
            writer: None,
            result: None,
            outputs: final_outputs,
            options: final_options,
        }
    }
    
}

impl MetaPlugin for MetaPluginExec {
    fn is_supported(&self) -> bool {
        self.supported
    }
    
    fn is_internal(&self) -> bool {
        false
    }

    fn initialize(&mut self) -> MetaPluginResponse {
        debug!("META: Initializing program plugin: {:?}", self);

        let program = self.program.clone();
        let args = self.args.clone();

        debug!("META: Executing command: {:?} {:?}", program, args);

        let mut process = match Command::new(program.clone())
            .args(args.clone())
            .stdin(Stdio::piped())
            .stdout(Stdio::piped())
            .stderr(Stdio::piped())
            .spawn() 
        {
            Ok(process) => process,
            Err(e) => {
                debug!("META: Failed to spawn process: {}", e);
                return MetaPluginResponse {
                    metadata: Vec::new(),
                    is_finalized: true,
                };
            }
        };

        let stdin = process.stdin.take().unwrap();
        self.writer = Some(Box::new(stdin));
        self.process = Some(process);

        MetaPluginResponse {
            metadata: Vec::new(),
            is_finalized: false,
        }
    }

    fn finalize(&mut self) -> MetaPluginResponse {
        debug!("META: Finalizing program plugin");
        let mut metadata = Vec::new();

        if let Some(process) = self.process.take() {
            // Close stdin to signal end of input
            drop(self.writer.take());

            // Wait for the process to complete
            let output = match process.wait_with_output() {
                Ok(output) => output,
                Err(e) => {
                    debug!("META: Failed to get process output: {}", e);
                    return MetaPluginResponse {
                        metadata: Vec::new(),
                        is_finalized: true,
                    };
                }
            };

            if output.status.success() {
                // Process the output
                let output_str = String::from_utf8_lossy(&output.stdout);
                let result = if self.split_whitespace {
                    output_str.split_whitespace().next().unwrap_or("").to_string()
                } else {
                    output_str.trim().to_string()
                };

                if !result.is_empty() {
                    debug!("META: Program output: {}", result);
                    self.result = Some(result.clone());

                    // Use process_metadata_outputs to handle output mapping
                    if let Some(meta_data) = crate::meta_plugin::process_metadata_outputs(
                        &self.meta_type().to_string(), 
                        serde_yaml::Value::String(result), 
                        &self.outputs
                    ) {
                        metadata.push(meta_data);
                    }
                }
            } else {
                debug!("META: Program failed with status: {:?}", output.status);
                let stderr = String::from_utf8_lossy(&output.stderr);
                if !stderr.is_empty() {
                    debug!("META: Program stderr: {}", stderr);
                }
            }
        }

        MetaPluginResponse {
            metadata,
            is_finalized: true,
        }
    }

    fn update(&mut self, data: &[u8]) -> MetaPluginResponse {
        if let Some(ref mut writer) = self.writer {
            if let Err(e) = writer.write_all(data) {
                debug!("META: Failed to write to process stdin: {}", e);
            }
        }
        MetaPluginResponse {
            metadata: Vec::new(),
            is_finalized: false,
        }
    }

    fn meta_type(&self) -> MetaPluginType {
        MetaPluginType::Exec
    }
    
    fn program_info(&self) -> Option<(&str, Vec<&str>)> {
        if self.supported {
            Some((&self.program, self.args.iter().map(|s| s.as_str()).collect()))
        } else {
            None
        }
    }
    
    fn outputs(&self) -> &std::collections::HashMap<String, serde_yaml::Value> {
        &self.outputs
    }
    
    fn outputs_mut(&mut self) -> &mut std::collections::HashMap<String, serde_yaml::Value> {
        &mut self.outputs
    }
    
    fn default_outputs(&self) -> Vec<String> {
        vec![self.meta_type().to_string()]
    }
    
    
    fn options(&self) -> &std::collections::HashMap<String, serde_yaml::Value> {
        &self.options
    }
    
    fn options_mut(&mut self) -> &mut std::collections::HashMap<String, serde_yaml::Value> {
        &mut self.options
    }
}