use std::collections::HashMap;

use super::chunk::chunk_text;
use super::client::{EmbedPayload, EmbedVector};
use super::embeddable::{EmbedMemoryInput, Embeddable};

/// Embedding and upsert operations for entity vectors in Qdrant.
impl super::EmbedService {
    pub async fn embed_issue(
        &self,
        id: &str,
        title: &str,
        body: Option<&str>,
    ) -> crate::Result<()> {
        let text = match body {
            Some(b) if !b.is_empty() => format!("{}\n\n{}", title, b),
            _ => title.to_string(),
        };

        tracing::debug!(issue_id = %id, text_len = text.len(), "embed_issue: calling embedding API");
        let vector = self.client.embed_text(&text, &self.model_name).await?;
        tracing::debug!(issue_id = %id, vec_dim = vector.len(), "embed_issue: embedding done");

        let point = EmbedVector {
            id: id.to_string(),
            vector,
            payload: EmbedPayload {
                entity_type: "issue".to_string(),
                entity_id: id.to_string(),
                text,
                extra: None,
            },
        };

        self.client.upsert(vec![point]).await?;
        tracing::info!(issue_id = %id, "embed_issue: upsert complete");
        Ok(())
    }

    pub async fn embed_repo(
        &self,
        id: &str,
        name: &str,
        description: Option<&str>,
    ) -> crate::Result<()> {
        let text = match description {
            Some(d) if !d.is_empty() => format!("{}: {}", name, d),
            _ => name.to_string(),
        };

        tracing::debug!(repo_id = %id, text_len = text.len(), "embed_repo: calling embedding API");
        let vector = self.client.embed_text(&text, &self.model_name).await?;
        tracing::debug!(repo_id = %id, vec_dim = vector.len(), "embed_repo: embedding done");

        let point = EmbedVector {
            id: id.to_string(),
            vector,
            payload: EmbedPayload {
                entity_type: "repo".to_string(),
                entity_id: id.to_string(),
                text,
                extra: None,
            },
        };

        self.client.upsert(vec![point]).await?;
        tracing::info!(repo_id = %id, "embed_repo: upsert complete");
        Ok(())
    }

    pub async fn embed_issues<T: Embeddable + Send + Sync>(
        &self,
        items: Vec<T>,
    ) -> crate::Result<()> {
        if items.is_empty() {
            return Ok(());
        }

        let texts: Vec<String> = items.iter().map(|i| i.to_text()).collect();
        tracing::debug!(count = texts.len(), "embed_issues: calling embed_batch");
        let embeddings = self.client.embed_batch(&texts, &self.model_name).await?;
        tracing::debug!(count = embeddings.len(), "embed_issues: batch done");

        let points: Vec<EmbedVector> = items
            .into_iter()
            .zip(embeddings.into_iter())
            .map(|(item, vector)| EmbedVector {
                id: item.entity_id(),
                vector,
                payload: EmbedPayload {
                    entity_type: item.entity_type().to_string(),
                    entity_id: item.entity_id(),
                    text: item.to_text(),
                    extra: None,
                },
            })
            .collect();

        let count = points.len();
        self.client.upsert(points).await?;
        tracing::info!(count = count, "embed_issues: upsert complete");
        Ok(())
    }

    pub async fn embed_skill(
        &self,
        skill_id: i64,
        name: &str,
        description: Option<&str>,
        content: &str,
        project_uuid: &str,
    ) -> crate::Result<()> {
        let desc = description.unwrap_or_default();
        let id = skill_id.to_string();

        tracing::debug!(skill_id = %skill_id, name = %name, content_len = content.len(), "embed_skill: starting");

        let texts = chunk_text(content);
        tracing::debug!(skill_id = %skill_id, chunks = texts.len(), "embed_skill: chunked");

        if texts.len() == 1 {
            self.client
                .embed_skill(&id, name, desc, content, project_uuid, &self.model_name)
                .await?;
        } else {
            let full_texts: Vec<String> = texts
                .iter()
                .map(|t| format!("{}: {} {}", name, desc, t))
                .collect();
            tracing::debug!(skill_id = %skill_id, "embed_skill: calling embed_batch");
            let embeddings = self
                .client
                .embed_batch(&full_texts, &self.model_name)
                .await?;

            let points: Vec<EmbedVector> = embeddings
                .into_iter()
                .enumerate()
                .map(|(i, vector)| EmbedVector {
                    id: format!("{}:chunk:{}", id, i),
                    vector,
                    payload: EmbedPayload {
                        entity_type: "skill".to_string(),
                        entity_id: project_uuid.to_string(),
                        text: texts[i].clone(),
                        extra: serde_json::json!({
                            "name": name,
                            "description": desc,
                            "chunk_index": i,
                            "total_chunks": texts.len(),
                        })
                        .into(),
                    },
                })
                .collect();

            self.client.upsert(points).await?;
        }
        tracing::info!(skill_id = %skill_id, chunks = texts.len(), "embed_skill: complete");
        Ok(())
    }

    pub async fn embed_issue_chunked(
        &self,
        id: &str,
        title: &str,
        body: Option<&str>,
    ) -> crate::Result<()> {
        let text = match body {
            Some(b) if !b.is_empty() => format!("{}\n\n{}", title, b),
            _ => title.to_string(),
        };

        let chunks = chunk_text(&text);
        if chunks.len() == 1 {
            return self.embed_issue(id, title, body).await;
        }

        let embeddings = self.client.embed_batch(&chunks, &self.model_name).await?;

        let points: Vec<EmbedVector> = embeddings
            .into_iter()
            .enumerate()
            .map(|(i, vector)| EmbedVector {
                id: format!("{}:chunk:{}", id, i),
                vector,
                payload: EmbedPayload {
                    entity_type: "issue".to_string(),
                    entity_id: id.to_string(),
                    text: chunks[i].clone(),
                    extra: serde_json::json!({
                        "chunk_index": i,
                        "total_chunks": chunks.len(),
                    })
                    .into(),
                },
            })
            .collect();

        self.client.upsert(points).await
    }

    pub async fn embed_memories_batch(&self, messages: Vec<EmbedMemoryInput>) -> crate::Result<()> {
        if messages.is_empty() {
            return Ok(());
        }

        let mut by_room: HashMap<String, Vec<(EmbedMemoryInput, Vec<String>)>> = HashMap::new();

        for msg in messages {
            let chunks = chunk_text(&msg.content);
            if chunks.is_empty() || chunks.iter().all(|c| c.trim().is_empty()) {
                continue;
            }
            let collection = super::qdrant::QdrantClient::room_memory_collection_name(
                &msg.project_name,
                &msg.room_id,
            );
            by_room.entry(collection).or_default().push((msg, chunks));
        }

        for (collection, entries) in &by_room {
            let all_texts: Vec<String> = entries
                .iter()
                .flat_map(|(_, chunks)| chunks.iter().cloned())
                .collect();

            if all_texts.is_empty() {
                continue;
            }

            let embeddings = self
                .client
                .embed_batch(&all_texts, &self.model_name)
                .await?;

            if let Some((first, _)) = entries.first() {
                let _ = self
                    .client
                    .ensure_room_memory_collection(
                        &first.project_name,
                        &first.room_id,
                        self.dimensions,
                    )
                    .await;
            }

            let mut points = Vec::new();
            let mut embed_idx = 0;
            for (msg, chunks) in entries {
                for (chunk_i, chunk) in chunks.iter().enumerate() {
                    if embed_idx >= embeddings.len() {
                        break;
                    }
                    let point_id = if chunks.len() == 1 {
                        msg.message_id.clone()
                    } else {
                        format!("{}:chunk:{}", msg.message_id, chunk_i)
                    };
                    points.push(EmbedVector {
                        id: point_id,
                        vector: embeddings[embed_idx].clone(),
                        payload: EmbedPayload {
                            entity_type: "memory".to_string(),
                            entity_id: msg.room_id.clone(),
                            text: chunk.clone(),
                            extra: serde_json::json!({
                                "message_id": msg.message_id,
                                "seq": msg.seq,
                                "user_id": msg.user_id,
                                "sender_type": msg.sender_type,
                                "chunk_index": if chunks.len() > 1 {
                                    Some(chunk_i)
                                } else {
                                    None
                                },
                                "total_chunks": if chunks.len() > 1 {
                                    Some(chunks.len())
                                } else {
                                    None
                                },
                            })
                            .into(),
                        },
                    });
                    embed_idx += 1;
                }
            }

            if let Err(e) = self.client.upsert_to_collection(collection, points).await {
                tracing::warn!(collection = %collection, error = %e, "batch memory embed failed");
            }
        }

        Ok(())
    }

    pub async fn embed_tags_batch(
        &self,
        tags: Vec<super::embeddable::TagEmbedInput>,
    ) -> crate::Result<()> {
        if tags.is_empty() {
            return Ok(());
        }

        let texts: Vec<String> = tags
            .iter()
            .map(|t| {
                if let Some(ref desc) = t.description {
                    if !desc.is_empty() {
                        format!("{}: {}", t.name, desc)
                    } else {
                        t.name.clone()
                    }
                } else {
                    t.name.clone()
                }
            })
            .collect();

        let embeddings = self.client.embed_batch(&texts, &self.model_name).await?;

        let points: Vec<EmbedVector> = tags
            .into_iter()
            .zip(embeddings.into_iter())
            .map(|(tag, vector)| {
                let point_id = format!("{}:{}", tag.repo_id, tag.name);
                EmbedVector {
                    id: point_id,
                    vector,
                    payload: EmbedPayload {
                        entity_type: "repo_tag".to_string(),
                        entity_id: tag.project_id.clone(),
                        text: tag.name.clone(),
                        extra: serde_json::json!({
                            "repo_id": tag.repo_id,
                            "repo_name": tag.repo_name,
                            "tag_name": tag.name,
                            "description": tag.description,
                        })
                        .into(),
                    },
                }
            })
            .collect();

        self.client.upsert(points).await
    }

    pub async fn embed_memory(
        &self,
        message_id: &str,
        text: &str,
        project_name: &str,
        room_id: &str,
        user_id: Option<&str>,
    ) -> crate::Result<()> {
        self.client
            .embed_memory(
                message_id,
                text,
                project_name,
                room_id,
                user_id,
                &self.model_name,
            )
            .await
    }
}