use std::ops::Range;

use common::{
    error::AppError,
    storage::{
        db::SurrealDbClient,
        types::{
            ingestion_task::IngestionTask, knowledge_entity::KnowledgeEntity,
            knowledge_relationship::KnowledgeRelationship, text_chunk::TextChunk,
            text_content::TextContent,
        },
    },
};
use retrieval_pipeline::RetrievedEntity;
use serde::{Deserialize, Serialize};
use tracing::error;

use super::enrichment_result::LLMEnrichmentResult;

use super::{config::IngestionConfig, services::PipelineServices};

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct EmbeddedKnowledgeEntity {
    pub entity: KnowledgeEntity,
    pub embedding: Vec<f32>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct EmbeddedTextChunk {
    pub chunk: TextChunk,
    pub embedding: Vec<f32>,
}

pub struct PipelineContext<'a> {
    pub task: &'a IngestionTask,
    pub task_id: String,
    pub attempt: u32,
    pub db: &'a SurrealDbClient,
    pub pipeline_config: &'a IngestionConfig,
    pub services: &'a dyn PipelineServices,
    pub text_content: Option<TextContent>,
    pub similar_entities: Vec<RetrievedEntity>,
    pub analysis: Option<LLMEnrichmentResult>,
}

#[derive(Debug)]
pub struct PipelineArtifacts {
    pub text_content: TextContent,
    pub entities: Vec<EmbeddedKnowledgeEntity>,
    pub relationships: Vec<KnowledgeRelationship>,
    pub chunks: Vec<EmbeddedTextChunk>,
}

impl<'a> PipelineContext<'a> {
    pub fn new(
        task: &'a IngestionTask,
        db: &'a SurrealDbClient,
        pipeline_config: &'a IngestionConfig,
        services: &'a dyn PipelineServices,
    ) -> Self {
        let task_id = task.id.clone();
        let attempt = task.attempts;
        Self {
            task,
            task_id,
            attempt,
            db,
            pipeline_config,
            services,
            text_content: None,
            similar_entities: Vec::new(),
            analysis: None,
        }
    }

    pub fn text_content(&self) -> Result<&TextContent, AppError> {
        self.text_content
            .as_ref()
            .ok_or_else(|| AppError::InternalError("text content expected to be available".into()))
    }

    pub fn take_text_content(&mut self) -> Result<TextContent, AppError> {
        self.text_content.take().ok_or_else(|| {
            AppError::InternalError("text content expected to be available for persistence".into())
        })
    }

    pub fn take_analysis(&mut self) -> Result<LLMEnrichmentResult, AppError> {
        self.analysis.take().ok_or_else(|| {
            AppError::InternalError("analysis expected to be available for persistence".into())
        })
    }

    pub fn abort(&mut self, err: AppError) -> AppError {
        error!(
            task_id = %self.task_id,
            attempt = self.attempt,
            error = %err,
            "ingestion pipeline aborted"
        );
        err
    }

    pub async fn build_artifacts(&mut self) -> Result<PipelineArtifacts, AppError> {
        if self.pipeline_config.chunk_only {
            return self.build_chunk_only_artifacts().await;
        }

        let content = self.take_text_content()?;
        let analysis = self.take_analysis()?;

        let (entities, relationships) = self.services.convert_analysis(&content, &analysis).await?;

        let chunk_range = self.chunk_token_range();
        let chunk_overlap = self.chunk_overlap_tokens();

        let chunks = self
            .services
            .prepare_chunks(&content, chunk_range, chunk_overlap)
            .await?;

        Ok(PipelineArtifacts {
            text_content: content,
            entities,
            relationships,
            chunks,
        })
    }

    pub async fn build_chunk_only_artifacts(&mut self) -> Result<PipelineArtifacts, AppError> {
        let content = self.take_text_content()?;
        let chunk_range = self.chunk_token_range();
        let chunk_overlap = self.chunk_overlap_tokens();

        let chunks = self
            .services
            .prepare_chunks(&content, chunk_range, chunk_overlap)
            .await?;

        Ok(PipelineArtifacts {
            text_content: content,
            entities: Vec::new(),
            relationships: Vec::new(),
            chunks,
        })
    }

    fn chunk_token_range(&self) -> Range<usize> {
        self.pipeline_config.tuning.chunk_min_tokens..self.pipeline_config.tuning.chunk_max_tokens
    }

    fn chunk_overlap_tokens(&self) -> usize {
        self.pipeline_config.tuning.chunk_overlap_tokens
    }
}