use async_trait::async_trait;
use serde::{Deserialize, Serialize};
use serde_json::{json, Value};
use sqlx::PgPool;
use std::sync::Arc;
use uuid::Uuid;

use crate::plugins::{
    hooks::HookContext, manager::PluginSystem, Plugin, PluginError, PluginMetadata, PluginScope,
};

pub struct StructuredDeliberationPlugin;

impl StructuredDeliberationPlugin {
    pub fn new() -> Self {
        Self
    }
}

#[async_trait]
impl Plugin for StructuredDeliberationPlugin {
    fn metadata(&self) -> PluginMetadata {
        PluginMetadata {
            name: "structured_deliberation",
            version: "1.0.0",
            description: "Pro/con arguments and collaborative summaries",
            is_core: false,
            scope: PluginScope::Community,
            default_enabled: true,
            settings_schema: Some(json!({
                "type": "object",
                "properties": {
                    "require_reading": {"type": "boolean", "default": true},
                    "enable_summaries": {"type": "boolean", "default": true}
                }
            })),
        }
    }

    fn register(&self, system: &mut PluginSystem) {
        // Hook: Check reading requirement before comment
        system.add_action(
            "comment.pre_create",
            "structured_deliberation".to_string(),
            5,
            Arc::new(|ctx: HookContext, payload: Value| {
                Box::pin(async move {
                    if let (Some(proposal_id), Some(user_id)) = (
                        payload
                            .get("proposal_id")
                            .and_then(|v| v.as_str())
                            .and_then(|s| Uuid::parse_str(s).ok()),
                        ctx.actor_user_id,
                    ) {
                        let can_comment = DeliberationService::check_can_participate(
                            &ctx.pool,
                            proposal_id,
                            user_id,
                            "comment",
                        )
                        .await?;

                        if !can_comment {
                            return Err(PluginError::Message(
                                "Please read the proposal before commenting".to_string(),
                            ));
                        }
                    }
                    Ok(())
                })
            }),
        );

        // Hook: Calculate metrics periodically
        system.add_action(
            "cron.hourly",
            "structured_deliberation".to_string(),
            50,
            Arc::new(|ctx: HookContext, _payload: Value| {
                Box::pin(async move {
                    DeliberationService::update_all_metrics(&ctx.pool).await?;
                    Ok(())
                })
            }),
        );

        // Hook: Track argument creation
        system.add_action(
            "deliberation.argument.created",
            "structured_deliberation".to_string(),
            50,
            Arc::new(|ctx: HookContext, payload: Value| {
                Box::pin(async move {
                    ctx.emit_public_event(
                        Some("structured_deliberation"),
                        "argument.created",
                        payload.clone(),
                    )
                    .await?;
                    Ok(())
                })
            }),
        );
    }
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Argument {
    pub id: Uuid,
    pub proposal_id: Uuid,
    pub stance: String,
    pub title: String,
    pub content: String,
    pub author_id: Uuid,
    pub upvotes: i32,
    pub downvotes: i32,
    pub quality_score: Option<f64>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Summary {
    pub id: Uuid,
    pub proposal_id: Uuid,
    pub summary_type: String,
    pub content: String,
    pub version: i32,
    pub is_approved: bool,
}

pub struct DeliberationService;

impl DeliberationService {
    /// Check if user can participate based on reading requirements
    pub async fn check_can_participate(
        pool: &PgPool,
        proposal_id: Uuid,
        user_id: Uuid,
        action: &str,
    ) -> Result<bool, PluginError> {
        let reading = sqlx::query!(
            r#"SELECT can_comment, can_vote FROM deliberation_reading_log
            WHERE proposal_id = $1 AND user_id = $2"#,
            proposal_id,
            user_id
        )
        .fetch_optional(pool)
        .await?;

        match reading {
            Some(r) => Ok(match action {
                "comment" => r.can_comment.unwrap_or(false),
                "vote" => r.can_vote.unwrap_or(false),
                _ => true,
            }),
            None => Ok(false), // No reading record
        }
    }

    /// Record that user has read content
    pub async fn record_reading(
        pool: &PgPool,
        proposal_id: Uuid,
        user_id: Uuid,
        read_type: &str,
        time_seconds: i32,
    ) -> Result<(), PluginError> {
        sqlx::query!(
            r#"INSERT INTO deliberation_reading_log (proposal_id, user_id, first_read_at, reading_time_seconds)
            VALUES ($1, $2, NOW(), $3)
            ON CONFLICT (proposal_id, user_id) DO UPDATE SET
                read_proposal = CASE WHEN $4 = 'proposal' THEN true ELSE deliberation_reading_log.read_proposal END,
                read_summaries = CASE WHEN $4 = 'summaries' THEN true ELSE deliberation_reading_log.read_summaries END,
                read_top_arguments = CASE WHEN $4 = 'arguments' THEN true ELSE deliberation_reading_log.read_top_arguments END,
                reading_time_seconds = deliberation_reading_log.reading_time_seconds + $3,
                updated_at = NOW()"#,
            proposal_id,
            user_id,
            time_seconds,
            read_type
        )
        .execute(pool)
        .await?;

        Ok(())
    }

    /// Add an argument
    pub async fn add_argument(
        pool: &PgPool,
        proposal_id: Uuid,
        parent_id: Option<Uuid>,
        stance: &str,
        title: &str,
        content: &str,
        author_id: Uuid,
    ) -> Result<Uuid, PluginError> {
        let argument_id: Uuid = sqlx::query_scalar(
            "SELECT add_deliberation_argument($1, $2, $3::argument_stance, $4, $5, $6)",
        )
        .bind(proposal_id)
        .bind(parent_id)
        .bind(stance)
        .bind(title)
        .bind(content)
        .bind(author_id)
        .fetch_one(pool)
        .await?;

        Ok(argument_id)
    }

    /// Vote on an argument
    pub async fn vote_argument(
        pool: &PgPool,
        argument_id: Uuid,
        user_id: Uuid,
        vote_type: &str,
    ) -> Result<(), PluginError> {
        sqlx::query("SELECT vote_on_argument($1, $2, $3)")
            .bind(argument_id)
            .bind(user_id)
            .bind(vote_type)
            .execute(pool)
            .await?;

        Ok(())
    }

    /// Get arguments for a proposal
    pub async fn get_arguments(
        pool: &PgPool,
        proposal_id: Uuid,
        stance: Option<&str>,
        limit: i64,
    ) -> Result<Vec<Argument>, PluginError> {
        let arguments = if let Some(s) = stance {
            sqlx::query_as!(
                Argument,
                r#"SELECT 
                    id, proposal_id, stance::text AS "stance!",
                    title, content, author_id,
                    upvotes, downvotes, quality_score::float8 AS quality_score
                FROM deliberation_arguments
                WHERE proposal_id = $1 AND stance::text = $2 AND NOT is_hidden AND parent_id IS NULL
                ORDER BY quality_score DESC NULLS LAST
                LIMIT $3"#,
                proposal_id,
                s,
                limit
            )
            .fetch_all(pool)
            .await?
        } else {
            sqlx::query_as!(
                Argument,
                r#"SELECT 
                    id, proposal_id, stance::text AS "stance!",
                    title, content, author_id,
                    upvotes, downvotes, quality_score::float8 AS quality_score
                FROM deliberation_arguments
                WHERE proposal_id = $1 AND NOT is_hidden AND parent_id IS NULL
                ORDER BY quality_score DESC NULLS LAST
                LIMIT $2"#,
                proposal_id,
                limit
            )
            .fetch_all(pool)
            .await?
        };

        Ok(arguments)
    }

    /// Create or update a summary
    pub async fn upsert_summary(
        pool: &PgPool,
        proposal_id: Uuid,
        summary_type: &str,
        content: &str,
        key_points: Value,
        editor_id: Uuid,
    ) -> Result<Uuid, PluginError> {
        // Check if summary exists
        let existing = sqlx::query_scalar!(
            "SELECT id FROM deliberation_summaries WHERE proposal_id = $1 AND summary_type = $2::summary_type",
            proposal_id,
            summary_type as _
        )
        .fetch_optional(pool)
        .await?;

        if let Some(summary_id) = existing {
            // Save to history
            sqlx::query!(
                r#"INSERT INTO summary_edit_history (summary_id, version, content, key_points, editor_id)
                SELECT id, version, content, key_points, last_editor_id
                FROM deliberation_summaries WHERE id = $1"#,
                summary_id
            )
            .execute(pool)
            .await?;

            // Update
            sqlx::query!(
                r#"UPDATE deliberation_summaries SET
                    content = $2, key_points = $3, last_editor_id = $4,
                    version = version + 1, edit_count = edit_count + 1,
                    is_approved = false, updated_at = NOW()
                WHERE id = $1"#,
                summary_id,
                content,
                key_points,
                editor_id
            )
            .execute(pool)
            .await?;

            Ok(summary_id)
        } else {
            // Create new
            let summary_id = sqlx::query_scalar!(
                r#"INSERT INTO deliberation_summaries (
                    proposal_id, summary_type, content, key_points, last_editor_id
                ) VALUES ($1, $2::summary_type, $3, $4, $5)
                RETURNING id"#,
                proposal_id,
                summary_type as _,
                content,
                key_points,
                editor_id
            )
            .fetch_one(pool)
            .await?;

            Ok(summary_id)
        }
    }

    /// Get summaries for a proposal
    pub async fn get_summaries(
        pool: &PgPool,
        proposal_id: Uuid,
    ) -> Result<Vec<Summary>, PluginError> {
        let summaries = sqlx::query_as!(
            Summary,
            r#"SELECT 
                id, proposal_id, summary_type::text AS "summary_type!",
                content, version, is_approved
            FROM deliberation_summaries
            WHERE proposal_id = $1
            ORDER BY summary_type"#,
            proposal_id
        )
        .fetch_all(pool)
        .await?;

        Ok(summaries)
    }

    /// Approve a summary
    pub async fn approve_summary(
        pool: &PgPool,
        summary_id: Uuid,
        approver_id: Uuid,
    ) -> Result<(), PluginError> {
        sqlx::query!(
            r#"UPDATE deliberation_summaries SET
                is_approved = true, approved_by = $2, approved_at = NOW()
            WHERE id = $1"#,
            summary_id,
            approver_id
        )
        .execute(pool)
        .await?;

        Ok(())
    }

    /// Update metrics for all active proposals
    pub async fn update_all_metrics(pool: &PgPool) -> Result<i32, PluginError> {
        let proposals = sqlx::query_scalar!(
            r#"SELECT DISTINCT proposal_id FROM deliberation_arguments
            WHERE created_at > NOW() - INTERVAL '1 day'"#
        )
        .fetch_all(pool)
        .await?;

        let mut count = 0;
        for proposal_id in proposals {
            sqlx::query("SELECT calculate_deliberation_metrics($1)")
                .bind(proposal_id)
                .execute(pool)
                .await?;
            count += 1;
        }

        Ok(count)
    }

    /// Get deliberation overview
    pub async fn get_overview(pool: &PgPool, proposal_id: Uuid) -> Result<Value, PluginError> {
        let metrics = sqlx::query!(
            r#"SELECT 
                total_arguments, pro_arguments, con_arguments, neutral_arguments,
                unique_participants, substantive_ratio::float8 AS substantive_ratio,
                balance_score::float8 AS balance_score
            FROM deliberation_metrics
            WHERE proposal_id = $1
            ORDER BY calculated_at DESC
            LIMIT 1"#,
            proposal_id
        )
        .fetch_optional(pool)
        .await?;

        let top_pro = Self::get_arguments(pool, proposal_id, Some("pro"), 3).await?;
        let top_con = Self::get_arguments(pool, proposal_id, Some("con"), 3).await?;
        let summaries = Self::get_summaries(pool, proposal_id).await?;

        Ok(json!({
            "metrics": metrics.map(|m| json!({
                "total_arguments": m.total_arguments,
                "pro": m.pro_arguments,
                "con": m.con_arguments,
                "neutral": m.neutral_arguments,
                "participants": m.unique_participants,
                "substantive_ratio": m.substantive_ratio,
                "balance_score": m.balance_score
            })),
            "top_pro_arguments": top_pro,
            "top_con_arguments": top_con,
            "summaries": summaries
        }))
    }
}