use sha2::{Digest, Sha256};

use crate::meta_plugin::MetaPlugin;

#[derive(Debug, Clone, Default)]
pub struct DigestSha256MetaPlugin {
    hasher: Sha256,
    is_finalized: bool,
    meta_name: String,
    outputs: std::collections::HashMap<String, serde_yaml::Value>,
    options: std::collections::HashMap<String, serde_yaml::Value>,
}

impl DigestSha256MetaPlugin {
    pub fn new(
        _options: Option<std::collections::HashMap<String, serde_yaml::Value>>,
        outputs: Option<std::collections::HashMap<String, serde_yaml::Value>>,
    ) -> DigestSha256MetaPlugin {
        // 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);
            }
        }
        
        // Start with default outputs
        let mut final_outputs = std::collections::HashMap::new();
        let default_outputs = vec!["digest_sha256".to_string()];
        for output_name in default_outputs {
            final_outputs.insert(output_name.clone(), serde_yaml::Value::String(output_name));
        }
        if let Some(outs) = outputs {
            for (key, value) in outs {
                final_outputs.insert(key, value);
            }
        }
        
        DigestSha256MetaPlugin {
            hasher: Sha256::new(),
            is_finalized: false,
            meta_name: "digest_sha256".to_string(),
            outputs: final_outputs,
            options: final_options,
        }
    }
    
    pub fn new_simple() -> DigestSha256MetaPlugin {
        Self::new(None, None)
    }
}

impl MetaPlugin for DigestSha256MetaPlugin {
    fn is_finalized(&self) -> bool {
        self.is_finalized
    }
    
    fn set_finalized(&mut self, finalized: bool) {
        self.is_finalized = finalized;
    }
    
    fn initialize(&mut self) -> crate::meta_plugin::MetaPluginResponse {
        crate::meta_plugin::MetaPluginResponse {
            metadata: Vec::new(),
            is_finalized: false,
        }
    }

    fn finalize(&mut self) -> crate::meta_plugin::MetaPluginResponse {
        // If already finalized, don't process again
        if self.is_finalized {
            return crate::meta_plugin::MetaPluginResponse {
                metadata: Vec::new(),
                is_finalized: true,
            };
        }
        
        let mut metadata = Vec::new();

        // Finalize the hash
        let hash_result = self.hasher.finalize_reset();
        let hex_string = format!("{:x}", hash_result);

        // Use process_metadata_outputs to handle output mapping
        if let Some(meta_data) = crate::meta_plugin::process_metadata_outputs(
            "digest_sha256", 
            hex_string, 
            &self.outputs
        ) {
            metadata.push(meta_data);
        }
        
        // Mark as finalized
        self.is_finalized = true;

        crate::meta_plugin::MetaPluginResponse {
            metadata,
            is_finalized: true,
        }
    }

    fn update(&mut self, data: &[u8]) -> crate::meta_plugin::MetaPluginResponse {
        // If already finalized, don't process more data
        if self.is_finalized {
            return crate::meta_plugin::MetaPluginResponse {
                metadata: Vec::new(),
                is_finalized: true,
            };
        }
        
        self.hasher.update(data);
        crate::meta_plugin::MetaPluginResponse {
            metadata: Vec::new(),
            is_finalized: false,
        }
    }

    fn meta_name(&self) -> String {
        self.meta_name.clone()
    }
    
    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!["digest_sha256".to_string()]
    }
    
    fn default_options(&self) -> std::collections::HashMap<String, serde_yaml::Value> {
        std::collections::HashMap::new()
    }
    
    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
    }
}