//! Collector Hand - Data collection and aggregation capabilities
//!
//! This hand provides web scraping, data extraction, and aggregation features.

use async_trait::async_trait;
use serde::{Deserialize, Serialize};
use serde_json::{json, Value};
use std::collections::HashMap;
use std::sync::Arc;
use tokio::sync::RwLock;
use zclaw_types::Result;

use crate::{Hand, HandConfig, HandContext, HandResult};

/// Output format options
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
#[serde(rename_all = "lowercase")]
pub enum OutputFormat {
    Json,
    Csv,
    Markdown,
    Text,
}

impl Default for OutputFormat {
    fn default() -> Self {
        Self::Json
    }
}

/// Collection target configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct CollectionTarget {
    /// URL to collect from
    pub url: String,
    /// CSS selector for items
    #[serde(default)]
    pub selector: Option<String>,
    /// Fields to extract
    #[serde(default)]
    pub fields: HashMap<String, String>,
    /// Maximum items to collect
    #[serde(default = "default_max_items")]
    pub max_items: usize,
}

fn default_max_items() -> usize { 100 }

/// Collected item
#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct CollectedItem {
    /// Source URL
    pub source_url: String,
    /// Collected data
    pub data: HashMap<String, Value>,
    /// Collection timestamp
    pub collected_at: String,
}

/// Collection result
#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct CollectionResult {
    /// Target URL
    pub url: String,
    /// Collected items
    pub items: Vec<CollectedItem>,
    /// Total items collected
    pub total_items: usize,
    /// Output format
    pub format: OutputFormat,
    /// Collection timestamp
    pub collected_at: String,
    /// Duration in ms
    pub duration_ms: u64,
}

/// Aggregation configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct AggregationConfig {
    /// URLs to aggregate
    pub urls: Vec<String>,
    /// Fields to aggregate
    #[serde(default)]
    pub aggregate_fields: Vec<String>,
}

/// Collector action types
#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(tag = "action")]
pub enum CollectorAction {
    #[serde(rename = "collect")]
    Collect { target: CollectionTarget, format: Option<OutputFormat> },
    #[serde(rename = "aggregate")]
    Aggregate { config: AggregationConfig },
    #[serde(rename = "extract")]
    Extract { url: String, selectors: HashMap<String, String> },
}

/// Collector Hand implementation
pub struct CollectorHand {
    config: HandConfig,
    client: reqwest::Client,
    cache: Arc<RwLock<HashMap<String, String>>>,
}

impl CollectorHand {
    /// Create a new collector hand
    pub fn new() -> Self {
        Self {
            config: HandConfig {
                id: "collector".to_string(),
                name: "数据采集器".to_string(),
                description: "从网页源收集和聚合数据".to_string(),
                needs_approval: false,
                dependencies: vec!["network".to_string()],
                input_schema: Some(serde_json::json!({
                    "type": "object",
                    "oneOf": [
                        {
                            "properties": {
                                "action": { "const": "collect" },
                                "target": {
                                    "type": "object",
                                    "properties": {
                                        "url": { "type": "string" },
                                        "selector": { "type": "string" },
                                        "fields": { "type": "object" },
                                        "maxItems": { "type": "integer" }
                                    },
                                    "required": ["url"]
                                },
                                "format": { "type": "string", "enum": ["json", "csv", "markdown", "text"] }
                            },
                            "required": ["action", "target"]
                        },
                        {
                            "properties": {
                                "action": { "const": "extract" },
                                "url": { "type": "string" },
                                "selectors": { "type": "object" }
                            },
                            "required": ["action", "url", "selectors"]
                        },
                        {
                            "properties": {
                                "action": { "const": "aggregate" },
                                "config": {
                                    "type": "object",
                                    "properties": {
                                        "urls": { "type": "array", "items": { "type": "string" } },
                                        "aggregateFields": { "type": "array", "items": { "type": "string" } }
                                    },
                                    "required": ["urls"]
                                }
                            },
                            "required": ["action", "config"]
                        }
                    ]
                })),
                tags: vec!["data".to_string(), "collection".to_string(), "scraping".to_string()],
                enabled: true,
            },
            client: reqwest::Client::builder()
                .timeout(std::time::Duration::from_secs(30))
                .user_agent("ZCLAW-Collector/1.0")
                .build()
                .unwrap_or_else(|_| reqwest::Client::new()),
            cache: Arc::new(RwLock::new(HashMap::new())),
        }
    }

    /// Fetch a page
    async fn fetch_page(&self, url: &str) -> Result<String> {
        // Check cache
        {
            let cache = self.cache.read().await;
            if let Some(cached) = cache.get(url) {
                return Ok(cached.clone());
            }
        }

        let response = self.client
            .get(url)
            .send()
            .await
            .map_err(|e| zclaw_types::ZclawError::HandError(format!("Request failed: {}", e)))?;

        let html = response.text().await
            .map_err(|e| zclaw_types::ZclawError::HandError(format!("Failed to read response: {}", e)))?;

        // Cache the result
        {
            let mut cache = self.cache.write().await;
            cache.insert(url.to_string(), html.clone());
        }

        Ok(html)
    }

    /// Extract text by simple pattern matching
    fn extract_by_pattern(&self, html: &str, pattern: &str) -> String {
        // Simple implementation: find text between tags
        if pattern.contains("title") || pattern.contains("h1") {
            if let Some(start) = html.find("<title>") {
                if let Some(end) = html[start..].find("</title>") {
                    return html[start + 7..start + end]
                        .replace("&amp;", "&")
                        .replace("&lt;", "<")
                        .replace("&gt;", ">")
                        .trim()
                        .to_string();
                }
            }
        }

        // Extract meta description
        if pattern.contains("description") || pattern.contains("meta") {
            if let Some(start) = html.find("name=\"description\"") {
                let rest = &html[start..];
                if let Some(content_start) = rest.find("content=\"") {
                    let content = &rest[content_start + 9..];
                    if let Some(end) = content.find('"') {
                        return content[..end].trim().to_string();
                    }
                }
            }
        }

        // Default: extract visible text
        self.extract_visible_text(html)
    }

    /// Extract visible text from HTML, stripping scripts and styles
    fn extract_visible_text(&self, html: &str) -> String {
        let html_lower = html.to_lowercase();
        let mut text = String::new();
        let mut in_tag = false;
        let mut in_script = false;
        let mut in_style = false;
        let mut pos: usize = 0;

        for c in html.chars() {
            let char_len = c.len_utf8();
            match c {
                '<' => {
                    let remaining = &html_lower[pos..];
                    if remaining.starts_with("</script") {
                        in_script = false;
                    } else if remaining.starts_with("</style") {
                        in_style = false;
                    }
                    if remaining.starts_with("<script") {
                        in_script = true;
                    } else if remaining.starts_with("<style") {
                        in_style = true;
                    }
                    in_tag = true;
                }
                '>' => {
                    in_tag = false;
                }
                _ if in_tag => {}
                _ if in_script || in_style => {}
                ' ' | '\n' | '\t' | '\r' => {
                    if !text.ends_with(' ') && !text.is_empty() {
                        text.push(' ');
                    }
                }
                _ => text.push(c),
            }
            pos += char_len;
        }

        if text.len() > 10000 {
            text.truncate(10000);
            text.push_str("...");
        }

        text.trim().to_string()
    }

    /// Execute collection
    async fn execute_collect(&self, target: &CollectionTarget, format: OutputFormat) -> Result<CollectionResult> {
        let start = std::time::Instant::now();
        let html = self.fetch_page(&target.url).await?;

        let mut items = Vec::new();
        let mut data = HashMap::new();

        // Extract fields
        for (field_name, selector) in &target.fields {
            let value = self.extract_by_pattern(&html, selector);
            data.insert(field_name.clone(), Value::String(value));
        }

        // If no fields specified, extract basic info
        if data.is_empty() {
            data.insert("title".to_string(), Value::String(self.extract_by_pattern(&html, "title")));
            data.insert("content".to_string(), Value::String(self.extract_visible_text(&html)));
        }

        items.push(CollectedItem {
            source_url: target.url.clone(),
            data,
            collected_at: chrono::Utc::now().to_rfc3339(),
        });

        Ok(CollectionResult {
            url: target.url.clone(),
            total_items: items.len(),
            items,
            format,
            collected_at: chrono::Utc::now().to_rfc3339(),
            duration_ms: start.elapsed().as_millis() as u64,
        })
    }

    /// Execute aggregation
    async fn execute_aggregate(&self, config: &AggregationConfig) -> Result<Value> {
        let start = std::time::Instant::now();
        let mut results = Vec::new();

        for url in config.urls.iter().take(10) {
            match self.fetch_page(url).await {
                Ok(html) => {
                    let mut data = HashMap::new();
                    for field in &config.aggregate_fields {
                        let value = self.extract_by_pattern(&html, field);
                        data.insert(field.clone(), Value::String(value));
                    }
                    if data.is_empty() {
                        data.insert("content".to_string(), Value::String(self.extract_visible_text(&html)));
                    }
                    results.push(data);
                }
                Err(e) => {
                    tracing::warn!(target: "collector", url = url, error = %e, "Failed to fetch");
                }
            }
        }

        Ok(json!({
            "results": results,
            "source_count": config.urls.len(),
            "duration_ms": start.elapsed().as_millis()
        }))
    }

    /// Execute extraction
    async fn execute_extract(&self, url: &str, selectors: &HashMap<String, String>) -> Result<HashMap<String, String>> {
        let html = self.fetch_page(url).await?;
        let mut results = HashMap::new();

        for (field_name, selector) in selectors {
            let value = self.extract_by_pattern(&html, selector);
            results.insert(field_name.clone(), value);
        }

        Ok(results)
    }
}

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

#[async_trait]
impl Hand for CollectorHand {
    fn config(&self) -> &HandConfig {
        &self.config
    }

    async fn execute(&self, _context: &HandContext, input: Value) -> Result<HandResult> {
        let action: CollectorAction = serde_json::from_value(input.clone())
            .map_err(|e| zclaw_types::ZclawError::HandError(format!("Invalid action: {}", e)))?;

        let start = std::time::Instant::now();

        let result = match action {
            CollectorAction::Collect { target, format } => {
                let fmt = format.unwrap_or(OutputFormat::Json);
                let collection = self.execute_collect(&target, fmt.clone()).await?;
                json!({
                    "action": "collect",
                    "url": target.url,
                    "total_items": collection.total_items,
                    "duration_ms": start.elapsed().as_millis(),
                    "items": collection.items
                })
            }
            CollectorAction::Aggregate { config } => {
                let aggregation = self.execute_aggregate(&config).await?;
                json!({
                    "action": "aggregate",
                    "duration_ms": start.elapsed().as_millis(),
                    "result": aggregation
                })
            }
            CollectorAction::Extract { url, selectors } => {
                let extracted = self.execute_extract(&url, &selectors).await?;
                json!({
                    "action": "extract",
                    "url": url,
                    "duration_ms": start.elapsed().as_millis(),
                    "data": extracted
                })
            }
        };

        Ok(HandResult::success(result))
    }

    fn needs_approval(&self) -> bool {
        false
    }

    fn check_dependencies(&self) -> Result<Vec<String>> {
        Ok(Vec::new())
    }

    fn status(&self) -> crate::HandStatus {
        crate::HandStatus::Idle
    }
}

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

    #[test]
    fn test_collector_config() {
        let hand = CollectorHand::new();
        assert_eq!(hand.config().id, "collector");
        assert_eq!(hand.config().name, "数据采集器");
        assert!(hand.config().enabled);
        assert!(!hand.config().needs_approval);
    }

    #[test]
    fn test_output_format_serialize() {
        let formats = vec![
            (OutputFormat::Csv, "\"csv\""),
            (OutputFormat::Markdown, "\"markdown\""),
            (OutputFormat::Json, "\"json\""),
            (OutputFormat::Text, "\"text\""),
        ];

        for (fmt, expected) in formats {
            let serialized = serde_json::to_string(&fmt).unwrap();
            assert_eq!(serialized, expected);
        }

        // Verify round-trip deserialization
        for json_str in &["\"csv\"", "\"markdown\"", "\"json\"", "\"text\""] {
            let deserialized: OutputFormat = serde_json::from_str(json_str).unwrap();
            let re_serialized = serde_json::to_string(&deserialized).unwrap();
            assert_eq!(&re_serialized, json_str);
        }
    }

    #[test]
    fn test_extract_visible_text_basic() {
        let hand = CollectorHand::new();
        let html = "<html><body><h1>Title</h1><p>Content here</p></body></html>";
        let text = hand.extract_visible_text(html);
        assert!(text.contains("Title"), "should contain 'Title', got: {}", text);
        assert!(text.contains("Content here"), "should contain 'Content here', got: {}", text);
    }

    #[test]
    fn test_extract_visible_text_strips_scripts() {
        let hand = CollectorHand::new();
        let html = "<html><body><script>alert('xss')</script><p>Safe content</p></body></html>";
        let text = hand.extract_visible_text(html);
        assert!(!text.contains("alert"), "script content should be removed, got: {}", text);
        assert!(!text.contains("xss"), "script content should be removed, got: {}", text);
        assert!(text.contains("Safe content"), "visible content should remain, got: {}", text);
    }

    #[test]
    fn test_extract_visible_text_strips_styles() {
        let hand = CollectorHand::new();
        let html = "<html><head><style>body { color: red; }</style></head><body><p>Text</p></body></html>";
        let text = hand.extract_visible_text(html);
        assert!(!text.contains("color"), "style content should be removed, got: {}", text);
        assert!(!text.contains("red"), "style content should be removed, got: {}", text);
        assert!(text.contains("Text"), "visible content should remain, got: {}", text);
    }

    #[test]
    fn test_extract_visible_text_empty() {
        let hand = CollectorHand::new();
        let text = hand.extract_visible_text("");
        assert!(text.is_empty(), "empty HTML should produce empty text, got: '{}'", text);
    }

    #[tokio::test]
    async fn test_aggregate_action_empty_urls() {
        let hand = CollectorHand::new();
        let config = AggregationConfig {
            urls: vec![],
            aggregate_fields: vec![],
        };

        let result = hand.execute_aggregate(&config).await.unwrap();
        let results = result.get("results").unwrap().as_array().unwrap();
        assert_eq!(results.len(), 0, "empty URLs should produce empty results");
        assert_eq!(result.get("source_count").unwrap().as_u64().unwrap(), 0);
    }

    #[test]
    fn test_collector_action_deserialize() {
        // Collect action
        let collect_json = json!({
            "action": "collect",
            "target": {
                "url": "https://example.com",
                "selector": ".article",
                "fields": { "title": "h1" },
                "maxItems": 10
            },
            "format": "markdown"
        });
        let action: CollectorAction = serde_json::from_value(collect_json).unwrap();
        match action {
            CollectorAction::Collect { target, format } => {
                assert_eq!(target.url, "https://example.com");
                assert_eq!(target.selector.as_deref(), Some(".article"));
                assert_eq!(target.max_items, 10);
                assert!(format.is_some());
                assert_eq!(format.unwrap(), OutputFormat::Markdown);
            }
            _ => panic!("Expected Collect action"),
        }

        // Aggregate action
        let aggregate_json = json!({
            "action": "aggregate",
            "config": {
                "urls": ["https://a.com", "https://b.com"],
                "aggregateFields": ["title", "content"]
            }
        });
        let action: CollectorAction = serde_json::from_value(aggregate_json).unwrap();
        match action {
            CollectorAction::Aggregate { config } => {
                assert_eq!(config.urls.len(), 2);
                assert_eq!(config.aggregate_fields.len(), 2);
            }
            _ => panic!("Expected Aggregate action"),
        }

        // Extract action
        let extract_json = json!({
            "action": "extract",
            "url": "https://example.com",
            "selectors": { "title": "h1", "body": "p" }
        });
        let action: CollectorAction = serde_json::from_value(extract_json).unwrap();
        match action {
            CollectorAction::Extract { url, selectors } => {
                assert_eq!(url, "https://example.com");
                assert_eq!(selectors.len(), 2);
            }
            _ => panic!("Expected Extract action"),
        }
    }

    #[test]
    fn test_collection_target_deserialize() {
        let json = json!({
            "url": "https://example.com/page",
            "selector": ".content",
            "fields": {
                "title": "h1",
                "author": ".author-name"
            },
            "maxItems": 50
        });

        let target: CollectionTarget = serde_json::from_value(json).unwrap();
        assert_eq!(target.url, "https://example.com/page");
        assert_eq!(target.selector.as_deref(), Some(".content"));
        assert_eq!(target.fields.len(), 2);
        assert_eq!(target.max_items, 50);
    }
}