use db::sqlx;
use git::rpc::{proto as p, proto::init_service_client::InitServiceClient};
use model::repos::{RepoModel, RepoTopicModel};
use serde::{Deserialize, Serialize};
use session::Session;

use crate::{
    AppService, Pagination, error::AppError, git::rpc_err,
    metrics::with_op_metric, session_user,
};

#[derive(Debug, Clone, Serialize, Deserialize, utoipa::ToSchema)]
pub struct RepoResponse {
    #[schema(value_type = String)]
    pub id: uuid::Uuid,
    pub name: String,
    pub description: Option<String>,
    pub default_branch: String,
    pub visibility: String,
    #[schema(value_type = i64)]
    pub size_bytes: i64,
    pub is_archived: bool,
    pub is_template: bool,
    pub is_mirror: bool,
    #[schema(value_type = String)]
    pub created_by: uuid::Uuid,
    #[schema(value_type = String)]
    pub created_at: chrono::DateTime<chrono::Utc>,
    #[schema(value_type = String)]
    pub updated_at: chrono::DateTime<chrono::Utc>,
}

pub fn repo_response(repo: RepoModel) -> RepoResponse {
    RepoResponse {
        id: repo.id,
        name: repo.name,
        description: repo.description,
        default_branch: repo.default_branch,
        visibility: repo.visibility,
        size_bytes: repo.size_bytes,
        is_archived: repo.is_archived,
        is_template: repo.is_template,
        is_mirror: repo.is_mirror,
        created_by: repo.created_by,
        created_at: repo.created_at,
        updated_at: repo.updated_at,
    }
}

#[derive(Debug, Clone, Deserialize, utoipa::ToSchema)]
pub struct UpdateRepo {
    pub name: Option<String>,
    pub description: Option<String>,
    pub default_branch: Option<String>,
    pub visibility: Option<String>,
    pub is_archived: Option<bool>,
    pub is_template: Option<bool>,
}

#[derive(Debug, Clone, Deserialize, utoipa::ToSchema)]
pub struct TransferRepo {
    pub target_workspace: String,
}

#[derive(Debug, Clone, Deserialize, utoipa::IntoParams)]
pub struct RepoFilter {
    pub visibility: Option<String>,
    pub is_archived: Option<bool>,
    pub search: Option<String>,
}

impl AppService {
    pub async fn repo_list(
        &self,
        ctx: &Session,
        wk_name: &str,
        filter: RepoFilter,
        pagination: Pagination,
    ) -> Result<Vec<RepoResponse>, AppError> {
        let user_uid = session_user(ctx)?;
        let wk = self.workspace_resolve(wk_name).await?;
        self.workspace_require_member(wk.id, user_uid).await?;

        let mut param_idx = 2;
        let mut sql = String::from(
            "SELECT id, wk, name, description, default_branch, visibility, size_bytes, \
             is_archived, is_template, is_mirror, created_by, storage_path, created_at, updated_at, deleted_at \
             FROM repo WHERE wk = $1 AND deleted_at IS NULL",
        );

        if filter.visibility.is_some() {
            sql.push_str(&format!(" AND visibility = ${param_idx}"));
            param_idx += 1;
        }
        if filter.is_archived.is_some() {
            sql.push_str(&format!(" AND is_archived = ${param_idx}"));
            param_idx += 1;
        }
        if filter.search.is_some() {
            sql.push_str(&format!(" AND name ILIKE ${param_idx}"));
            param_idx += 1;
        }

        let offset_idx = param_idx;
        let limit_idx = param_idx + 1;
        sql.push_str(&format!(
            " ORDER BY name ASC OFFSET ${offset_idx} LIMIT ${limit_idx}"
        ));

        let mut q = sqlx::query_as::<_, RepoModel>(sqlx::AssertSqlSafe(sql))
            .bind(wk.id);

        if let Some(vis) = &filter.visibility {
            q = q.bind(vis.clone());
        }
        if let Some(archived) = filter.is_archived {
            q = q.bind(archived);
        }
        if let Some(search) = &filter.search {
            q = q.bind(format!("%{}%", search));
        }

        q = q
            .bind(pagination.offset() as i64)
            .bind(pagination.limit() as i64);

        let rows = q
            .fetch_all(self.db.reader())
            .await
            .map_err(|e| AppError::DatabaseError(e.to_string()))?;

        Ok(rows.into_iter().map(repo_response).collect())
    }

    pub async fn repo_get(
        &self,
        ctx: &Session,
        wk_name: &str,
        repo_name: &str,
    ) -> Result<RepoResponse, AppError> {
        let repo = self.git_require_member(ctx, wk_name, repo_name).await?;
        Ok(repo_response(repo))
    }

    pub async fn repo_update(
        &self,
        ctx: &Session,
        wk_name: &str,
        repo_name: &str,
        params: UpdateRepo,
    ) -> Result<RepoResponse, AppError> {
        with_op_metric(&self.metrics.repo_operations_total, &["update"], async {
            let user_uid = session_user(ctx)?;
        let wk = self.workspace_resolve(wk_name).await?;
        self.workspace_require_admin(wk.id, user_uid).await?;
        let mut repo = self.repo_resolve(wk.id, repo_name).await?;

        let next_name = match params.name {
            Some(name) => {
                let name = name.trim();
                if name.is_empty() {
                    return Err(AppError::BadRequest(
                        "repo name is required".to_string(),
                    ));
                }
                if name != repo.name {
                    let existing = sqlx::query_scalar::<_, bool>(
                        "SELECT EXISTS(SELECT 1 FROM repo WHERE wk = $1 AND name = $2 AND deleted_at IS NULL)",
                    )
                    .bind(wk.id)
                    .bind(name)
                    .fetch_one(self.db.reader())
                    .await
                    .map_err(|e| AppError::DatabaseError(e.to_string()))?;
                    if existing {
                        return Err(AppError::RepoNameAlreadyExists);
                    }
                    Some(name.to_string())
                } else {
                    None
                }
            }
            None => None,
        };

        let mut txn = self.db.begin().await.map_err(|_| AppError::TxnError)?;

        if let Some(next_name) = &next_name {
            sqlx::query(
                "INSERT INTO repo_history_name (id, repo, name, changed_by, created_at) \
                 VALUES ($1, $2, $3, $4, $5)",
            )
            .bind(uuid::Uuid::now_v7())
            .bind(repo.id)
            .bind(&repo.name)
            .bind(user_uid)
            .bind(chrono::Utc::now())
            .execute(&mut **txn.inner_mut())
            .await
            .map_err(|e| AppError::DatabaseError(e.to_string()))?;
            repo.name = next_name.clone();
        }

        if let Some(desc) = params.description {
            repo.description = if desc.is_empty() { None } else { Some(desc) };
        }
        let mut default_branch_changed = false;
        if let Some(branch) = params.default_branch {
            repo.default_branch = branch;
            default_branch_changed = true;
        }
        if let Some(vis) = params.visibility {
            repo.visibility = vis;
        }
        if let Some(archived) = params.is_archived {
            repo.is_archived = archived;
        }
        if let Some(template) = params.is_template {
            repo.is_template = template;
        }

        let updated = sqlx::query_as::<_, RepoModel>(
            "UPDATE repo SET name = $1, description = $2, default_branch = $3, \
             visibility = $4, is_archived = $5, is_template = $6, updated_at = $7 \
             WHERE id = $8 \
             RETURNING id, wk, name, description, default_branch, visibility, size_bytes, \
             is_archived, is_template, is_mirror, created_by, storage_path, created_at, updated_at, deleted_at",
        )
        .bind(&repo.name)
        .bind(&repo.description)
        .bind(&repo.default_branch)
        .bind(&repo.visibility)
        .bind(repo.is_archived)
        .bind(repo.is_template)
        .bind(chrono::Utc::now())
        .bind(repo.id)
        .fetch_one(&mut **txn.inner_mut())
        .await
        .map_err(|e| AppError::DatabaseError(e.to_string()))?;

        txn.commit().await.map_err(|_| AppError::TxnError)?;
        if default_branch_changed {
            let mut client = InitServiceClient::new(self.git.clone());
            let _ = client
                .set_default_branch(tonic::Request::new(
                    p::SetDefaultBranchRequest {
                        repo_id: repo.id.to_string(),
                        branch_name: repo.default_branch.clone(),
                    },
                ))
                .await
                .map_err(rpc_err);
            self.queue_sync(repo.id).await;
        }

            Ok(repo_response(updated))
        }).await
    }

    pub async fn repo_archive(
        &self,
        ctx: &Session,
        wk_name: &str,
        repo_name: &str,
    ) -> Result<RepoResponse, AppError> {
        self.repo_update(
            ctx,
            wk_name,
            repo_name,
            UpdateRepo {
                name: None,
                description: None,
                default_branch: None,
                visibility: None,
                is_archived: Some(true),
                is_template: None,
            },
        )
        .await
    }

    pub async fn repo_delete(
        &self,
        ctx: &Session,
        wk_name: &str,
        repo_name: &str,
    ) -> Result<(), AppError> {
        with_op_metric(
            &self.metrics.repo_operations_total,
            &["delete"],
            async {
                let user_uid = session_user(ctx)?;
                let wk = self.workspace_resolve(wk_name).await?;
                self.workspace_require_owner(wk.id, user_uid).await?;
                let repo = self.repo_resolve(wk.id, repo_name).await?;

                sqlx::query("UPDATE repo SET deleted_at = $1 WHERE id = $2")
                    .bind(chrono::Utc::now())
                    .bind(repo.id)
                    .execute(self.db.writer())
                    .await
                    .map_err(|e| AppError::DatabaseError(e.to_string()))?;

                Ok(())
            },
        )
        .await
    }

    pub async fn repo_transfer(
        &self,
        ctx: &Session,
        wk_name: &str,
        repo_name: &str,
        params: TransferRepo,
    ) -> Result<RepoResponse, AppError> {
        with_op_metric(&self.metrics.repo_transfer_total, &[], async {
            let user_uid = session_user(ctx)?;
        let src_wk = self.workspace_resolve(wk_name).await?;
        self.workspace_require_owner(src_wk.id, user_uid).await?;
        let repo = self.repo_resolve(src_wk.id, repo_name).await?;

        let target_wk =
            self.workspace_resolve(&params.target_workspace).await?;
        self.workspace_require_admin(target_wk.id, user_uid).await?;

        let existing = sqlx::query_scalar::<_, bool>(
            "SELECT EXISTS(SELECT 1 FROM repo WHERE wk = $1 AND name = $2 AND deleted_at IS NULL)",
        )
        .bind(target_wk.id)
        .bind(&repo.name)
        .fetch_one(self.db.reader())
        .await
        .map_err(|e| AppError::DatabaseError(e.to_string()))?;
        if existing {
            return Err(AppError::Conflict(
                "repo name already exists in target workspace".to_string(),
            ));
        }

        let mut txn = self.db.begin().await.map_err(|_| AppError::TxnError)?;

        sqlx::query(
            "INSERT INTO repo_history_name (id, repo, name, changed_by, created_at) \
             VALUES ($1, $2, $3, $4, $5)",
        )
        .bind(uuid::Uuid::now_v7())
        .bind(repo.id)
        .bind(&format!("{}/{}", src_wk.name, repo.name))
        .bind(user_uid)
        .bind(chrono::Utc::now())
        .execute(&mut **txn.inner_mut())
        .await
        .map_err(|e| AppError::DatabaseError(e.to_string()))?;

        let updated = sqlx::query_as::<_, RepoModel>(
            "UPDATE repo SET wk = $1, updated_at = $2 WHERE id = $3 \
             RETURNING id, wk, name, description, default_branch, visibility, size_bytes, \
             is_archived, is_template, is_mirror, created_by, storage_path, created_at, updated_at, deleted_at",
        )
        .bind(target_wk.id)
        .bind(chrono::Utc::now())
        .bind(repo.id)
        .fetch_one(&mut **txn.inner_mut())
        .await
        .map_err(|e| AppError::DatabaseError(e.to_string()))?;

        txn.commit().await.map_err(|_| AppError::TxnError)?;
            Ok(repo_response(updated))
        }).await
    }

    pub async fn repo_topics(
        &self,
        ctx: &Session,
        wk_name: &str,
        repo_name: &str,
    ) -> Result<Vec<String>, AppError> {
        let repo = self.git_require_member(ctx, wk_name, repo_name).await?;

        let rows = sqlx::query_as::<_, RepoTopicModel>(
            "SELECT repo, topic, created_at FROM repo_topic WHERE repo = $1",
        )
        .bind(repo.id)
        .fetch_all(self.db.reader())
        .await
        .map_err(|e| AppError::DatabaseError(e.to_string()))?;

        Ok(rows.into_iter().map(|r| r.topic).collect())
    }

    pub async fn repo_update_topics(
        &self,
        ctx: &Session,
        wk_name: &str,
        repo_name: &str,
        topics: Vec<String>,
    ) -> Result<Vec<String>, AppError> {
        let user_uid = session_user(ctx)?;
        let wk = self.workspace_resolve(wk_name).await?;
        self.workspace_require_admin(wk.id, user_uid).await?;
        let repo = self.repo_resolve(wk.id, repo_name).await?;

        let mut txn = self.db.begin().await.map_err(|_| AppError::TxnError)?;

        sqlx::query("DELETE FROM repo_topic WHERE repo = $1")
            .bind(repo.id)
            .execute(&mut **txn.inner_mut())
            .await
            .map_err(|e| AppError::DatabaseError(e.to_string()))?;

        for topic in &topics {
            let topic = topic.trim();
            if topic.is_empty() {
                continue;
            }
            sqlx::query(
                "INSERT INTO repo_topic (repo, topic, created_at) VALUES ($1, $2, $3)",
            )
            .bind(repo.id)
            .bind(topic)
            .bind(chrono::Utc::now())
            .execute(&mut **txn.inner_mut())
            .await
            .map_err(|e| AppError::DatabaseError(e.to_string()))?;
        }

        txn.commit().await.map_err(|_| AppError::TxnError)?;
        Ok(topics)
    }

    /// CMDK BFF: list repo names + descriptions for a workspace.
    pub async fn repo_list_inner(
        &self,
        wk_name: &str,
    ) -> Result<Vec<(String, Option<String>)>, AppError> {
        let wk = sqlx::query_as::<_, (uuid::Uuid,)>(
            "SELECT id FROM workspace WHERE name = $1",
        )
        .bind(wk_name)
        .fetch_optional(self.db.reader())
        .await
        .map_err(|e| AppError::DatabaseError(e.to_string()))?
        .ok_or_else(|| AppError::NotFound("workspace not found".to_string()))?;

        let rows = sqlx::query_as::<_, (String, Option<String>)>(
            "SELECT name, description FROM repo WHERE wk = $1 AND deleted_at IS NULL ORDER BY updated_at DESC"
        )
        .bind(wk.0)
        .fetch_all(self.db.reader())
        .await
        .map_err(|e| AppError::DatabaseError(e.to_string()))?;
        Ok(rows)
    }
}