use crate::error::{GeneratorError, Result};
use serde::{Deserialize, Serialize};
use std::path::Path;

#[derive(Debug, Clone)]
pub struct ApiRouterGenerator {
    pub router_url: String,
    pub api_secret: String,
    pub openrouter_api_key: Option<String>,
}

#[derive(Debug, Serialize)]
struct ImageRequest {
    prompt: String,
    model: String,
}

#[derive(Debug, Deserialize)]
struct ImageResponse {
    statut: String,
    donnees: Option<ImageData>,
}

#[derive(Debug, Deserialize)]
struct ImageData {
    #[serde(rename = "imageUrl")]
    image_url: Option<String>,
}

impl ApiRouterGenerator {
    pub fn new(router_url: String, api_secret: String, openrouter_api_key: Option<String>) -> Self {
        Self {
            router_url,
            api_secret,
            openrouter_api_key,
        }
    }

    async fn download_image(&self, url: &str, output_path: &Path) -> Result<bool> {
        let response = reqwest::get(url)
            .await
            .map_err(GeneratorError::RequestError)?;

        let bytes = response.bytes().await.map_err(GeneratorError::RequestError)?;
        std::fs::write(output_path, bytes)?;
        Ok(true)
    }

    pub async fn generate(
        &self,
        prompt: &str,
        output_path: &Path,
        scene_index: usize,
        is_last: bool,
    ) -> Result<bool> {
        let horror_hook = if scene_index == 1 {
            "SHOCKING HORROR: terrified face or lunging monster, "
        } else {
            ""
        };

        let branding = if is_last {
            " with 'Darkmedia-X' branding text visible"
        } else {
            ""
        };

        let styled_prompt = format!(
            "Dark Anime Horror, {}{}{branding}. 9:16 ratio, ink-wash, high resolution.",
            horror_hook, prompt
        );

        let payload = ImageRequest {
            prompt: styled_prompt,
            model: "openai/dall-e-3".to_string(),
        };

        let client = reqwest::Client::new();
        let url = format!("{}/api/image", self.router_url.trim_end_matches('/'));

        let response = client
            .post(&url)
            .header("Authorization", format!("Bearer {}", self.api_secret))
            .header("Content-Type", "application/json")
            .json(&payload)
            .timeout(std::time::Duration::from_secs(45))
            .send()
            .await;

        match response {
            Ok(resp) => {
                let status = resp.status();

                if status == 404 {
                    eprintln!("      [WARN] Router 404 — fallback direct");
                    return self.fallback_direct(prompt, output_path, is_last).await;
                }

                if !status.is_success() {
                    eprintln!("      [WARN] Router returned status {} — fallback direct", status);
                    return self.fallback_direct(prompt, output_path, is_last).await;
                }

                if let Ok(data) = resp.json::<ImageResponse>().await {
                    if data.statut == "actif" {
                        if let Some(image_data) = data.donnees {
                            if let Some(img_url) = image_data.image_url {
                                return self.download_image(&img_url, output_path).await;
                            }
                        }
                    }
                }
                Ok(false)
            }
            Err(e) => {
                eprintln!("      [WARN] Router inaccessible — fallback direct: {}", e);
                self.fallback_direct(prompt, output_path, is_last).await
            }
        }
    }

    async fn fallback_direct(&self, prompt: &str, output_path: &Path, is_last: bool) -> Result<bool> {
        let api_key = self.openrouter_api_key.as_ref()
            .ok_or_else(|| GeneratorError::ApiError("OPENROUTER_API_KEY not configured".to_string()))?;

        let branding = if is_last {
            " with 'Darkmedia-X' branding text visible"
        } else {
            ""
        };

        let styled_prompt = format!(
            "Dark Anime Cinematic Horror Style: {}{branding}. High resolution, 9:16 vertical ratio, ink-wash textures, moody lighting.",
            prompt
        );

        let client = reqwest::Client::new();

        #[derive(Serialize)]
        struct OpenRouterRequest {
            model: String,
            prompt: String,
            n: usize,
            size: String,
        }

        let payload = OpenRouterRequest {
            model: "openai/dall-e-3".to_string(),
            prompt: styled_prompt,
            n: 1,
            size: "1024x1792".to_string(),
        };

        let response = client
            .post("https://openrouter.ai/api/v1/images/generations")
            .header("Authorization", format!("Bearer {}", api_key))
            .json(&payload)
            .timeout(std::time::Duration::from_secs(120))
            .send()
            .await?;

        if !response.status().is_success() {
            eprintln!("         🔴 OpenRouter error: {} status", response.status());
            if let Ok(text) = response.text().await {
                eprintln!("            Response: {}", &text[..std::cmp::min(200, text.len())]);
            }
            return Err(GeneratorError::ApiError("OpenRouter API error".to_string()));
        }

        #[derive(Deserialize)]
        struct OpenRouterResponse {
            data: Vec<OpenRouterImage>,
        }

        #[derive(Deserialize)]
        struct OpenRouterImage {
            url: String,
        }

        match response.json::<OpenRouterResponse>().await {
            Ok(data) => {
                if let Some(img) = data.data.first() {
                    return self.download_image(&img.url, output_path).await;
                }
                Ok(false)
            }
            Err(e) => {
                eprintln!("         🔴 OpenRouter JSON error: {}", e);
                Err(e.into())
            }
        }
    }
}

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

    #[test]
    fn test_api_router_new() {
        let generator = ApiRouterGenerator::new(
            "http://localhost:8080".to_string(),
            "secret".to_string(),
            Some("openrouter_key".to_string()),
        );
        assert_eq!(generator.router_url, "http://localhost:8080");
        assert_eq!(generator.api_secret, "secret");
        assert_eq!(generator.openrouter_api_key, Some("openrouter_key".to_string()));
    }
}