//! PPTX Exporter - PowerPoint presentation export
//!
//! Generates a .pptx file (Office Open XML format) containing:
//! - Title slide
//! - Content slides for each scene
//! - Speaker notes (optional)
//! - Quiz slides
//!
//! Note: This is a simplified implementation that creates a valid PPTX structure
//! without external dependencies. For more advanced features, consider using
//! a dedicated library like `pptx-rs` or `office` crate.

use crate::generation::{Classroom, GeneratedScene, SceneContent, SceneAction};
use super::{ExportOptions, ExportResult, Exporter, sanitize_filename};
use zclaw_types::{Result, ZclawError};
use std::collections::HashMap;

/// PPTX exporter
pub struct PptxExporter;

impl PptxExporter {
    /// Create new PPTX exporter
    pub fn new() -> Self {
        Self
    }

    /// Generate PPTX content (as bytes)
    fn generate_pptx(&self, classroom: &Classroom, options: &ExportOptions) -> Result<Vec<u8>> {
        let mut files: HashMap<String, Vec<u8>> = HashMap::new();

        // [Content_Types].xml
        files.insert(
            "[Content_Types].xml".to_string(),
            self.generate_content_types().into_bytes(),
        );

        // _rels/.rels
        files.insert(
            "_rels/.rels".to_string(),
            self.generate_rels().into_bytes(),
        );

        // docProps/app.xml
        files.insert(
            "docProps/app.xml".to_string(),
            self.generate_app_xml(classroom).into_bytes(),
        );

        // docProps/core.xml
        files.insert(
            "docProps/core.xml".to_string(),
            self.generate_core_xml(classroom).into_bytes(),
        );

        // ppt/presentation.xml
        files.insert(
            "ppt/presentation.xml".to_string(),
            self.generate_presentation_xml(classroom).into_bytes(),
        );

        // ppt/_rels/presentation.xml.rels
        files.insert(
            "ppt/_rels/presentation.xml.rels".to_string(),
            self.generate_presentation_rels(classroom, options).into_bytes(),
        );

        // Generate slides
        let mut slide_files = self.generate_slides(classroom, options);
        for (path, content) in slide_files.drain() {
            files.insert(path, content);
        }

        // Create ZIP archive
        self.create_zip_archive(files)
    }

    /// Generate [Content_Types].xml
    fn generate_content_types(&self) -> String {
        r#"<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Types xmlns="http://schemas.openxmlformats.org/package/2006/content-types">
  <Default Extension="rels" ContentType="application/vnd.openxmlformats-package.relationships+xml"/>
  <Default Extension="xml" ContentType="application/xml"/>
  <Override PartName="/ppt/presentation.xml" ContentType="application/vnd.openxmlformats-officedocument.presentationml.presentation.main+xml"/>
  <Override PartName="/docProps/core.xml" ContentType="application/vnd.openxmlformats-package.core-properties+xml"/>
  <Override PartName="/docProps/app.xml" ContentType="application/vnd.openxmlformats-officedocument.extended-properties+xml"/>
  <Override PartName="/ppt/slide1.xml" ContentType="application/vnd.openxmlformats-officedocument.presentationml.slide+xml"/>
</Types>"#.to_string()
    }

    /// Generate _rels/.rels
    fn generate_rels(&self) -> String {
        r#"<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships">
  <Relationship Id="rId1" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument" Target="ppt/presentation.xml"/>
  <Relationship Id="rId2" Type="http://schemas.openxmlformats.org/package/2006/relationships/metadata/core-properties" Target="docProps/core.xml"/>
  <Relationship Id="rId3" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/extended-properties" Target="docProps/app.xml"/>
</Relationships>"#.to_string()
    }

    /// Generate docProps/app.xml
    fn generate_app_xml(&self, classroom: &Classroom) -> String {
        format!(
            r#"<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Properties xmlns="http://schemas.openxmlformats.org/officeDocument/2006/extended-properties">
  <Application>ZCLAW Classroom Generator</Application>
  <Slides>{}</Slides>
  <Title>{}</Title>
  <Subject>{}</Subject>
</Properties>"#,
            classroom.scenes.len() + 1, // +1 for title slide
            xml_escape(&classroom.title),
            xml_escape(&classroom.topic)
        )
    }

    /// Generate docProps/core.xml
    fn generate_core_xml(&self, classroom: &Classroom) -> String {
        let created = chrono::DateTime::from_timestamp_millis(classroom.metadata.generated_at)
            .map(|dt| dt.format("%Y-%m-%dT%H:%M:%SZ").to_string())
            .unwrap_or_else(|| "2024-01-01T00:00:00Z".to_string());

        format!(
            r#"<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<cp:coreProperties xmlns:cp="http://schemas.openxmlformats.org/package/2006/metadata/core-properties" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:dcterms="http://purl.org/dc/terms/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <dc:title>{}</dc:title>
  <dc:subject>{}</dc:subject>
  <dc:description>{}</dc:description>
  <dcterms:created xsi:type="dcterms:W3CDTF">{}</dcterms:created>
  <cp:revision>1</cp:revision>
</cp:coreProperties>"#,
            xml_escape(&classroom.title),
            xml_escape(&classroom.topic),
            xml_escape(&classroom.description),
            created
        )
    }

    /// Generate ppt/presentation.xml
    fn generate_presentation_xml(&self, classroom: &Classroom) -> String {
        let slide_count = classroom.scenes.len() + 1; // +1 for title slide
        let slide_ids: String = (1..=slide_count)
            .map(|i| format!(r#"    <p:sldId id="{}" r:id="rId{}"/>"#, 255 + i, i))
            .collect::<Vec<_>>()
            .join("\n");

        format!(
            r#"<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<p:presentation xmlns:a="http://schemas.openxmlformats.org/drawingml/2006/main" xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships" xmlns:p="http://schemas.openxmlformats.org/presentationml/2006/main">
  <p:sldIdLst>
{}
  </p:sldIdLst>
  <p:sldSz cx="9144000" cy="6858000"/>
  <p:notesSz cx="6858000" cy="9144000"/>
</p:presentation>"#,
            slide_ids
        )
    }

    /// Generate ppt/_rels/presentation.xml.rels
    fn generate_presentation_rels(&self, classroom: &Classroom, _options: &ExportOptions) -> String {
        let slide_count = classroom.scenes.len() + 1;
        let relationships: String = (1..=slide_count)
            .map(|i| {
                format!(
                    r#"  <Relationship Id="rId{}" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/slide" Target="slides/slide{}.xml"/>"#,
                    i, i
                )
            })
            .collect::<Vec<_>>()
            .join("\n");

        format!(
            r#"<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships">
{}
</Relationships>"#,
            relationships
        )
    }

    /// Generate all slide files
    fn generate_slides(&self, classroom: &Classroom, options: &ExportOptions) -> HashMap<String, Vec<u8>> {
        let mut files = HashMap::new();

        // Title slide (slide1.xml)
        let title_slide = self.generate_title_slide(classroom);
        files.insert("ppt/slides/slide1.xml".to_string(), title_slide.into_bytes());

        // Content slides
        for (i, scene) in classroom.scenes.iter().enumerate() {
            let slide_num = i + 2; // Start from 2 (1 is title)
            let slide_xml = self.generate_content_slide(scene, options);
            files.insert(
                format!("ppt/slides/slide{}.xml", slide_num),
                slide_xml.into_bytes(),
            );
        }

        // Slide relationships
        let slide_count = classroom.scenes.len() + 1;
        for i in 1..=slide_count {
            let rels = self.generate_slide_rels(i);
            files.insert(
                format!("ppt/slides/_rels/slide{}.xml.rels", i),
                rels.into_bytes(),
            );
        }

        files
    }

    /// Generate title slide XML
    fn generate_title_slide(&self, classroom: &Classroom) -> String {
        let _objectives = classroom.objectives.iter()
            .map(|o| format!("- {}", o))
            .collect::<Vec<_>>()
            .join("\n");

        format!(
            r#"<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<p:sld xmlns:a="http://schemas.openxmlformats.org/drawingml/2006/main" xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships" xmlns:p="http://schemas.openxmlformats.org/presentationml/2006/main">
  <p:cSld>
    <p:spTree>
      <p:nvGrpSpPr>
        <p:cNvPr id="1" name=""/>
        <p:nvPr/>
      </p:nvGrpSpPr>
      <p:grpSpPr>
        <a:xfrm>
          <a:off x="0" y="0"/>
          <a:ext cx="0" cy="0"/>
          <a:chOff x="0" y="0"/>
          <a:chExt cx="0" cy="0"/>
        </a:xfrm>
      </p:grpSpPr>
      <p:sp>
        <p:nvSpPr>
          <p:cNvPr id="2" name="Title"/>
          <p:nvPr>
            <p:ph type="ctrTitle"/>
          </p:nvPr>
        </p:nvSpPr>
        <p:spPr>
          <a:xfrm>
            <a:off x="457200" y="2746388"/>
            <a:ext cx="8229600" cy="1143000"/>
          </a:xfrm>
        </p:spPr>
        <p:txBody>
          <a:bodyPr/>
          <a:p>
            <a:r>
              <a:rPr lang="zh-CN"/>
              <a:t>{}</a:t>
            </a:r>
          </a:p>
        </p:txBody>
      </p:sp>
      <p:sp>
        <p:nvSpPr>
          <p:cNvPr id="3" name="Subtitle"/>
          <p:nvPr>
            <p:ph type="subTitle"/>
          </p:nvPr>
        </p:nvSpPr>
        <p:spPr>
          <a:xfrm>
            <a:off x="457200" y="4039388"/>
            <a:ext cx="8229600" cy="609600"/>
          </a:xfrm>
        </p:spPr>
        <p:txBody>
          <a:bodyPr/>
          <a:p>
            <a:r>
              <a:rPr lang="zh-CN"/>
              <a:t>{}</a:t>
            </a:r>
          </a:p>
          <a:p>
            <a:r>
              <a:rPr lang="zh-CN"/>
              <a:t>Duration: {}</a:t>
            </a:r>
          </a:p>
        </p:txBody>
      </p:sp>
    </p:spTree>
  </p:cSld>
</p:sld>"#,
            xml_escape(&classroom.title),
            xml_escape(&classroom.description),
            format_duration(classroom.total_duration)
        )
    }

    /// Generate content slide XML
    fn generate_content_slide(&self, scene: &GeneratedScene, options: &ExportOptions) -> String {
        let content_text = self.extract_scene_content(&scene.content);
        let notes = if options.include_notes {
            scene.content.notes.as_ref()
                .map(|n| self.generate_notes(n))
                .unwrap_or_default()
        } else {
            String::new()
        };

        format!(
            r#"<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<p:sld xmlns:a="http://schemas.openxmlformats.org/drawingml/2006/main" xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships" xmlns:p="http://schemas.openxmlformats.org/presentationml/2006/main">
  <p:cSld>
    <p:spTree>
      <p:nvGrpSpPr>
        <p:cNvPr id="1" name=""/>
        <p:nvPr/>
      </p:nvGrpSpPr>
      <p:grpSpPr>
        <a:xfrm>
          <a:off x="0" y="0"/>
          <a:ext cx="0" cy="0"/>
          <a:chOff x="0" y="0"/>
          <a:chExt cx="0" cy="0"/>
        </a:xfrm>
      </p:grpSpPr>
      <p:sp>
        <p:nvSpPr>
          <p:cNvPr id="2" name="Title"/>
          <p:nvPr>
            <p:ph type="title"/>
          </p:nvPr>
        </p:nvSpPr>
        <p:spPr>
          <a:xfrm>
            <a:off x="457200" y="274638"/>
            <a:ext cx="8229600" cy="1143000"/>
          </a:xfrm>
        </p:spPr>
        <p:txBody>
          <a:bodyPr/>
          <a:p>
            <a:r>
              <a:rPr lang="zh-CN"/>
              <a:t>{}</a:t>
            </a:r>
          </a:p>
        </p:txBody>
      </p:sp>
      <p:sp>
        <p:nvSpPr>
          <p:cNvPr id="3" name="Content"/>
          <p:nvPr>
            <p:ph type="body"/>
          </p:nvPr>
        </p:nvSpPr>
        <p:spPr>
          <a:xfrm>
            <a:off x="457200" y="1600200"/>
            <a:ext cx="8229600" cy="4572000"/>
          </a:xfrm>
        </p:spPr>
        <p:txBody>
          <a:bodyPr/>
{}
        </p:txBody>
      </p:sp>
    </p:spTree>
  </p:cSld>
{}
</p:sld>"#,
            xml_escape(&scene.content.title),
            content_text,
            notes
        )
    }

    /// Extract scene content as PPTX paragraphs
    fn extract_scene_content(&self, content: &SceneContent) -> String {
        let mut paragraphs = String::new();

        // Add description
        if let Some(desc) = content.content.get("description").and_then(|v| v.as_str()) {
            paragraphs.push_str(&self.text_to_paragraphs(desc));
        }

        // Add key points
        if let Some(points) = content.content.get("key_points").and_then(|v| v.as_array()) {
            for point in points {
                if let Some(text) = point.as_str() {
                    paragraphs.push_str(&self.bullet_point_paragraph(text));
                }
            }
        }

        // Add speech content
        for action in &content.actions {
            if let SceneAction::Speech { text, agent_role } = action {
                let prefix = if agent_role != "teacher" {
                    format!("[{}]: ", agent_role)
                } else {
                    String::new()
                };
                paragraphs.push_str(&self.text_to_paragraphs(&format!("{}{}", prefix, text)));
            }
        }

        if paragraphs.is_empty() {
            paragraphs.push_str(&self.text_to_paragraphs("Content for this scene."));
        }

        paragraphs
    }

    /// Convert text to PPTX paragraphs
    fn text_to_paragraphs(&self, text: &str) -> String {
        text.lines()
            .filter(|l| !l.trim().is_empty())
            .map(|line| {
                format!(
                    r#"          <a:p>
            <a:r>
              <a:rPr lang="zh-CN"/>
              <a:t>{}</a:t>
            </a:r>
          </a:p>
"#,
                    xml_escape(line.trim())
                )
            })
            .collect()
    }

    /// Create bullet point paragraph
    fn bullet_point_paragraph(&self, text: &str) -> String {
        format!(
            r#"          <a:p>
            <a:pPr lvl="1">
              <a:buFont typeface="Arial"/>
              <a:buChar char="•"/>
            </a:pPr>
            <a:r>
              <a:rPr lang="zh-CN"/>
              <a:t>{}</a:t>
            </a:r>
          </a:p>
"#,
            xml_escape(text)
        )
    }

    /// Generate speaker notes XML
    fn generate_notes(&self, notes: &str) -> String {
        format!(
            r#"  <p:notes>
    <p:cSld>
      <p:spTree>
        <p:sp>
          <p:txBody>
            <a:bodyPr/>
            <a:p>
              <a:r>
                <a:t>{}</a:t>
              </a:r>
            </a:p>
          </p:txBody>
        </p:sp>
      </p:spTree>
    </p:cSld>
  </p:notes>"#,
            xml_escape(notes)
        )
    }

    /// Generate slide relationships
    fn generate_slide_rels(&self, _slide_num: usize) -> String {
        r#"<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships">
</Relationships>"#.to_string()
    }

    /// Create ZIP archive from files
    fn create_zip_archive(&self, files: HashMap<String, Vec<u8>>) -> Result<Vec<u8>> {
        use std::io::{Cursor, Write};

        let mut buffer = Cursor::new(Vec::new());
        {
            let mut writer = ZipWriter::new(&mut buffer);

            // Add files in sorted order (required by ZIP spec for deterministic output)
            let mut paths: Vec<_> = files.keys().collect();
            paths.sort();

            for path in paths {
                let content = files.get(path).expect("path comes from files.keys(), must exist");
                let options = SimpleFileOptions::default()
                    .compression_method(zip::CompressionMethod::Deflated);

                writer.start_file(path, options)
                    .map_err(|e| ZclawError::ExportError(e.to_string()))?;
                writer.write_all(content)
                    .map_err(|e| ZclawError::ExportError(e.to_string()))?;
            }

            writer.finish()
                .map_err(|e| ZclawError::ExportError(e.to_string()))?;
        }

        Ok(buffer.into_inner())
    }
}

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

impl Exporter for PptxExporter {
    fn export(&self, classroom: &Classroom, options: &ExportOptions) -> Result<ExportResult> {
        let content = self.generate_pptx(classroom, options)?;
        let filename = format!("{}.pptx", sanitize_filename(&classroom.title));

        Ok(ExportResult {
            content,
            mime_type: "application/vnd.openxmlformats-officedocument.presentationml.presentation".to_string(),
            filename,
            extension: "pptx".to_string(),
        })
    }

    fn format(&self) -> super::ExportFormat {
        super::ExportFormat::Pptx
    }

    fn extension(&self) -> &str {
        "pptx"
    }

    fn mime_type(&self) -> &str {
        "application/vnd.openxmlformats-officedocument.presentationml.presentation"
    }
}

// Helper functions

/// Escape XML special characters
fn xml_escape(s: &str) -> String {
    s.replace('&', "&amp;")
        .replace('<', "&lt;")
        .replace('>', "&gt;")
        .replace('"', "&quot;")
        .replace('\'', "&apos;")
}

/// Format duration
fn format_duration(seconds: u32) -> String {
    let minutes = seconds / 60;
    let secs = seconds % 60;
    if secs > 0 {
        format!("{}m {}s", minutes, secs)
    } else {
        format!("{}m", minutes)
    }
}

// ZIP writing (minimal implementation)
use zip::{ZipWriter, write::SimpleFileOptions};

#[cfg(test)]
mod tests {
    use super::*;
    use crate::generation::{ClassroomMetadata, TeachingStyle, DifficultyLevel, SceneType};

    fn create_test_classroom() -> Classroom {
        Classroom {
            id: "test-1".to_string(),
            title: "Test Classroom".to_string(),
            description: "A test classroom".to_string(),
            topic: "Testing".to_string(),
            style: TeachingStyle::Lecture,
            level: DifficultyLevel::Beginner,
            total_duration: 1800,
            objectives: vec!["Learn A".to_string(), "Learn B".to_string()],
            scenes: vec![
                GeneratedScene {
                    id: "scene-1".to_string(),
                    outline_id: "outline-1".to_string(),
                    content: SceneContent {
                        title: "Introduction".to_string(),
                        scene_type: SceneType::Slide,
                        content: serde_json::json!({
                            "description": "Intro slide content",
                            "key_points": ["Point 1", "Point 2"]
                        }),
                        actions: vec![SceneAction::Speech {
                            text: "Welcome!".to_string(),
                            agent_role: "teacher".to_string(),
                        }],
                        duration_seconds: 600,
                        notes: Some("Speaker notes here".to_string()),
                    },
                    order: 0,
                },
            ],
            agents: vec![],
            metadata: ClassroomMetadata::default(),
        }
    }

    #[test]
    fn test_pptx_export() {
        let exporter = PptxExporter::new();
        let classroom = create_test_classroom();
        let options = ExportOptions::default();

        let result = exporter.export(&classroom, &options).unwrap();

        assert_eq!(result.extension, "pptx");
        assert!(result.filename.ends_with(".pptx"));
        assert!(!result.content.is_empty());

        // Verify it's a valid ZIP file
        let cursor = std::io::Cursor::new(&result.content);
        let mut archive = zip::ZipArchive::new(cursor).unwrap();
        assert!(archive.by_name("[Content_Types].xml").is_ok());
        assert!(archive.by_name("ppt/presentation.xml").is_ok());
    }

    #[test]
    fn test_xml_escape() {
        assert_eq!(xml_escape("Hello <World>"), "Hello &lt;World&gt;");
        assert_eq!(xml_escape("A & B"), "A &amp; B");
        assert_eq!(xml_escape("Say \"Hi\""), "Say &quot;Hi&quot;");
    }

    #[test]
    fn test_pptx_format() {
        let exporter = PptxExporter::new();
        assert_eq!(exporter.extension(), "pptx");
        assert_eq!(exporter.format(), super::super::ExportFormat::Pptx);
    }
}