use anyhow::Result;
use async_trait::async_trait;
use std::sync::Arc;
use tokio::sync::RwLock;

use super::Database;
use crate::core::config;
use crate::core::storage::snapshot_manager::SnapshotTier;

pub struct RedisDb {
    #[allow(dead_code)]
    state: Arc<RwLock<RedisState>>,
}

#[derive(Debug, Clone, Default)]
pub struct RedisState {
    pub processing: Vec<String>,
    pub completed: Vec<String>,
    pub failed: Vec<String>,
}

#[derive(Debug, serde::Serialize, serde::Deserialize)]
pub struct Job {
    pub id: String,
    pub uuid: String,
    pub job_type: String,
    pub status: String,
    pub progress: f32,
    pub created_at: String,
    pub updated_at: String,
}

#[derive(Debug, serde::Serialize, serde::Deserialize)]
pub struct SnapshotCacheEntry {
    pub hits: u64,
    pub last_access: i64,
    pub status: String,
    pub progress: Option<f32>,
}

impl RedisDb {
    pub async fn push_job(&self, _job: &Job) -> Result<()> {
        Ok(())
    }

    pub async fn get_pending_jobs(&self) -> Result<Vec<Job>> {
        Ok(vec![])
    }

    pub async fn update_job_status(
        &self,
        _job_id: &str,
        _status: &str,
        _progress: f32,
    ) -> Result<()> {
        Ok(())
    }

    pub async fn publish_event(&self, _channel: &str, _message: &str) -> Result<()> {
        Ok(())
    }

    // --- Snapshot Cache Methods ---

    pub async fn increment_snapshot_hits(&self, _file_uuid: &str) -> Result<u64> {
        // TODO: Redis HINCRBY snapshot:hits:{uuid}
        Ok(0)
    }

    pub async fn get_snapshot_hits(&self, _file_uuid: &str) -> Result<u64> {
        // TODO: Redis GET snapshot:hits:{uuid}
        Ok(0)
    }

    pub async fn update_last_access(&self, _file_uuid: &str) -> Result<()> {
        // TODO: Redis SET snapshot:last_access:{uuid} = now EX 7d
        Ok(())
    }

    pub async fn set_snapshot_status(
        &self,
        _file_uuid: &str,
        status: &str,
        progress: Option<f32>,
    ) -> Result<()> {
        // TODO: Redis SET snapshot:status:{uuid} = {status, progress} EX 30m
        let _ = (status, progress);
        Ok(())
    }

    pub async fn get_snapshot_status(&self, _file_uuid: &str) -> Result<SnapshotCacheEntry> {
        // TODO: Redis GET snapshot:status:{uuid}
        Ok(SnapshotCacheEntry {
            hits: 0,
            last_access: 0,
            status: "cold".to_string(),
            progress: None,
        })
    }

    pub async fn clear_snapshot_status(&self, _file_uuid: &str) -> Result<()> {
        // TODO: Redis DEL snapshot:status:{uuid}
        Ok(())
    }

    pub async fn set_migrate_hint(
        &self,
        _file_uuid: &str,
        _parent_uuid: &str,
        _count: u64,
    ) -> Result<()> {
        // TODO: Redis SET snapshot:migrate_hint:{uuid}
        Ok(())
    }

    pub async fn get_migrate_hint(&self, _file_uuid: &str) -> Result<Option<(String, u64)>> {
        // TODO: Redis GET snapshot:migrate_hint:{uuid}
        Ok(None)
    }

    pub fn compute_status_ttl(&self, tier: SnapshotTier) -> u64 {
        match tier {
            SnapshotTier::Hot => *config::snapshot::HOT_TTL_SECS,
            SnapshotTier::Warm => *config::snapshot::WARM_TTL_SECS,
            SnapshotTier::Cold => 0,
        }
    }

    pub fn generating_timeout() -> u64 {
        *config::snapshot::GENERATING_TIMEOUT_SECS
    }
}

#[async_trait]
impl Database for RedisDb {
    async fn init() -> Result<Self> {
        // TODO: Initialize Redis client
        Ok(Self {
            state: Arc::new(RwLock::new(RedisState::default())),
        })
    }
}
