use regex::Regex;
use serde::{Deserialize, Serialize};

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ScriptureSection {
    pub verse: String,
    pub reference: String,
}

/// Format raw scripture text into structured sections with verses and references
pub fn format_scripture_text(text: &str) -> Vec<ScriptureSection> {
    // Handle single-line format where verse and reference are together
    if text.contains(" KJV") && !text.contains('\n') {
        // Single line format: "verse text. Book chapter:verse KJV"
        if let Some(kjv_pos) = text.rfind(" KJV") {
            let before_kjv = &text[..kjv_pos];
            // Find the last period or other punctuation that separates verse from reference
            if let Some(last_period) = before_kjv.rfind('.') {
                if let Some(reference_start) = before_kjv[last_period..].find(char::is_alphabetic) {
                    let actual_start = last_period + reference_start;
                    let verse_text = format!("{}.", &before_kjv[..last_period]);
                    let reference = format!("{} KJV", &before_kjv[actual_start..]);
                    return vec![ScriptureSection {
                        verse: verse_text.trim().to_string(),
                        reference: reference.trim().to_string(),
                    }];
                }
            }
        }
        // Fallback: treat entire text as verse with no separate reference
        return vec![ScriptureSection {
            verse: text.to_string(),
            reference: String::new(),
        }];
    }

    // Multi-line format (original logic)
    let sections: Vec<&str> = text.split('\n').collect();
    let mut formatted_sections = Vec::new();
    let mut current_verse = String::new();

    for section in sections {
        let trimmed = section.trim();
        if trimmed.is_empty() {
            continue;
        }

        // Check if this line is a reference (contains "KJV" at the end)
        if trimmed.ends_with("KJV") {
            // This is a reference for the verse we just accumulated
            if !current_verse.is_empty() {
                formatted_sections.push(ScriptureSection {
                    verse: current_verse.clone(),
                    reference: trimmed.to_string(),
                });
                current_verse.clear(); // Reset for next verse
            }
        } else {
            // This is verse text
            if !current_verse.is_empty() {
                current_verse.push(' ');
            }
            current_verse.push_str(trimmed);
        }
    }

    // Add any remaining verse without a reference
    if !current_verse.is_empty() {
        formatted_sections.push(ScriptureSection {
            verse: current_verse,
            reference: String::new(),
        });
    }

    formatted_sections
}

/// Extract scripture references from text (e.g., "Joel 2:28 KJV" patterns)
pub fn extract_scripture_references(text: &str) -> String {
    let pattern = r"([1-3]?\s*[A-Za-z]+\s+\d+:\d+(?:-\d+)?)\s+KJV";
    
    match Regex::new(pattern) {
        Ok(regex) => {
            let references: Vec<String> = regex
                .captures_iter(text)
                .filter_map(|cap| cap.get(1).map(|m| m.as_str().trim().to_string()))
                .collect();
            
            if references.is_empty() {
                "Scripture Reading".to_string()
            } else {
                references.join(", ")
            }
        }
        Err(_) => "Scripture Reading".to_string(),
    }
}

/// Create standardized share text for sermons
pub fn create_sermon_share_text(title: &str, speaker: &str, video_url: Option<&str>, audio_url: Option<&str>) -> Vec<String> {
    let mut items = Vec::new();
    
    // Create share text
    let share_text = format!("Check out this sermon: \"{}\" by {}", title, speaker);
    items.push(share_text);
    
    // Add video URL if available, otherwise audio URL
    if let Some(url) = video_url {
        items.push(url.to_string());
    } else if let Some(url) = audio_url {
        items.push(url.to_string());
    }
    
    items
}

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

    #[test]
    fn test_single_line_scripture_format() {
        let input = "And it shall come to pass afterward, that I will pour out my spirit upon all flesh. Joel 2:28 KJV";
        let result = format_scripture_text(input);
        
        assert_eq!(result.len(), 1);
        assert_eq!(result[0].verse, "And it shall come to pass afterward, that I will pour out my spirit upon all flesh.");
        assert_eq!(result[0].reference, "Joel 2:28 KJV");
    }

    #[test]
    fn test_multi_line_scripture_format() {
        let input = "And it shall come to pass afterward, that I will pour out my spirit upon all flesh\nJoel 2:28 KJV\nQuench not the Spirit. Despise not prophesyings.\n1 Thessalonians 5:19-21 KJV";
        let result = format_scripture_text(input);
        
        assert_eq!(result.len(), 2);
        assert_eq!(result[0].verse, "And it shall come to pass afterward, that I will pour out my spirit upon all flesh");
        assert_eq!(result[0].reference, "Joel 2:28 KJV");
        assert_eq!(result[1].verse, "Quench not the Spirit. Despise not prophesyings.");
        assert_eq!(result[1].reference, "1 Thessalonians 5:19-21 KJV");
    }

    #[test]
    fn test_extract_scripture_references() {
        let input = "Some text with Joel 2:28 KJV and 1 Thessalonians 5:19-21 KJV references";
        let result = extract_scripture_references(input);
        
        assert_eq!(result, "Joel 2:28, 1 Thessalonians 5:19-21");
    }

    #[test]
    fn test_create_sermon_share_text() {
        let result = create_sermon_share_text(
            "Test Sermon", 
            "John Doe", 
            Some("https://example.com/video"), 
            Some("https://example.com/audio")
        );
        
        assert_eq!(result.len(), 2);
        assert_eq!(result[0], "Check out this sermon: \"Test Sermon\" by John Doe");
        assert_eq!(result[1], "https://example.com/video");
    }
}