use uuid::Uuid;

use crate::error::AppError;
use crate::models::common::Role;
use crate::models::issues::IssueTemplate;
use crate::service::IssueService;
use crate::session::Session;

use super::util::{clamp_limit_offset, ensure_affected, required_text};

#[derive(serde::Deserialize, serde::Serialize, Clone, Debug, utoipa::ToSchema)]
pub struct CreateTemplateParams {
    pub name: String,
    pub description: Option<String>,
    pub title_template: Option<String>,
    pub body_template: String,
    pub labels: Vec<String>,
}

#[derive(serde::Deserialize, serde::Serialize, Clone, Debug, utoipa::ToSchema)]
pub struct UpdateTemplateParams {
    pub name: Option<String>,
    pub description: Option<String>,
    pub title_template: Option<String>,
    pub body_template: Option<String>,
    pub labels: Option<Vec<String>>,
    pub active: Option<bool>,
}

impl IssueService {
    pub async fn issue_templates(
        &self,
        ctx: &Session,
        wk_name: &str,
        repo_name: &str,
        limit: i64,
        offset: i64,
    ) -> Result<Vec<IssueTemplate>, AppError> {
        let user_uid = ctx.user().ok_or(AppError::Unauthorized)?;
        let repo_id = self.resolve_repo_id(wk_name, repo_name).await?;
        let repo = crate::models::repos::Repo::find_by_id(self.ctx.db.reader(), repo_id)
            .await
            .map_err(AppError::Database)?
            .ok_or(AppError::NotFound("repo not found".into()))?;
        self.ensure_repo_readable(user_uid, &repo).await?;
        let (limit, offset) = clamp_limit_offset(limit, offset);
        sqlx::query_as::<_, IssueTemplate>(
            "SELECT id, repo_id, name, description, title_template, body_template, labels, \
             active, created_by, created_at, updated_at \
             FROM issue_template WHERE repo_id = $1 AND active = true \
             ORDER BY name ASC LIMIT $2 OFFSET $3",
        )
        .bind(repo_id)
        .bind(limit)
        .bind(offset)
        .fetch_all(self.ctx.db.reader())
        .await
        .map_err(AppError::Database)
    }

    pub async fn issue_create_template(
        &self,
        ctx: &Session,
        wk_name: &str,
        repo_name: &str,
        params: CreateTemplateParams,
    ) -> Result<IssueTemplate, AppError> {
        let user_uid = ctx.user().ok_or(AppError::Unauthorized)?;
        let repo_id = self.resolve_repo_id(wk_name, repo_name).await?;
        self.ensure_repo_role(repo_id, user_uid, Role::Member)
            .await?;
        let name = required_text(params.name, "name")?;
        let body_template = required_text(params.body_template, "body_template")?;
        let now = chrono::Utc::now();
        sqlx::query_as::<_, IssueTemplate>(
            "INSERT INTO issue_template (id, repo_id, name, description, title_template, body_template, \
             labels, active, created_by, created_at, updated_at) \
             VALUES ($1, $2, $3, $4, $5, $6, $7, true, $8, $9, $9) \
             RETURNING id, repo_id, name, description, title_template, body_template, labels, \
             active, created_by, created_at, updated_at",
        )
        .bind(Uuid::now_v7()).bind(repo_id).bind(&name).bind(params.description.as_deref())
        .bind(params.title_template.as_deref()).bind(&body_template)
        .bind(sqlx::types::Json(&params.labels)).bind(user_uid).bind(now)
        .fetch_one(self.ctx.db.writer()).await.map_err(AppError::Database)
    }

    pub async fn issue_update_template(
        &self,
        ctx: &Session,
        wk_name: &str,
        repo_name: &str,
        template_id: Uuid,
        params: UpdateTemplateParams,
    ) -> Result<IssueTemplate, AppError> {
        let user_uid = ctx.user().ok_or(AppError::Unauthorized)?;
        let repo_id = self.resolve_repo_id(wk_name, repo_name).await?;
        self.ensure_repo_role(repo_id, user_uid, Role::Admin)
            .await?;
        let current = sqlx::query_as::<_, IssueTemplate>(
            "SELECT id, repo_id, name, description, title_template, body_template, labels, \
             active, created_by, created_at, updated_at \
             FROM issue_template WHERE id = $1 AND repo_id = $2",
        )
        .bind(template_id)
        .bind(repo_id)
        .fetch_optional(self.ctx.db.reader())
        .await
        .map_err(AppError::Database)?
        .ok_or(AppError::NotFound("template not found".into()))?;

        let name = params.name.unwrap_or(current.name);
        let description = params.description.or(current.description);
        let title_template = params.title_template.or(current.title_template);
        let body_template = params.body_template.unwrap_or(current.body_template);
        let labels = params.labels.unwrap_or(current.labels);
        let active = params.active.unwrap_or(current.active);
        let now = chrono::Utc::now();

        sqlx::query_as::<_, IssueTemplate>(
            "UPDATE issue_template SET name = $1, description = $2, title_template = $3, \
             body_template = $4, labels = $5, active = $6, updated_at = $7 WHERE id = $8 \
             RETURNING id, repo_id, name, description, title_template, body_template, labels, \
             active, created_by, created_at, updated_at",
        )
        .bind(&name)
        .bind(&description)
        .bind(&title_template)
        .bind(&body_template)
        .bind(sqlx::types::Json(&labels))
        .bind(active)
        .bind(now)
        .bind(template_id)
        .fetch_one(self.ctx.db.writer())
        .await
        .map_err(AppError::Database)
    }

    pub async fn issue_delete_template(
        &self,
        ctx: &Session,
        wk_name: &str,
        repo_name: &str,
        template_id: Uuid,
    ) -> Result<(), AppError> {
        let user_uid = ctx.user().ok_or(AppError::Unauthorized)?;
        let repo_id = self.resolve_repo_id(wk_name, repo_name).await?;
        self.ensure_repo_role(repo_id, user_uid, Role::Admin)
            .await?;
        let result = sqlx::query("DELETE FROM issue_template WHERE id = $1 AND repo_id = $2")
            .bind(template_id)
            .bind(repo_id)
            .execute(self.ctx.db.writer())
            .await
            .map_err(AppError::Database)?;
        ensure_affected(result.rows_affected(), "template not found")
    }
}