use serde::{Deserialize, Serialize};
use uuid::Uuid;

use crate::error::AppError;
use crate::models::common::Role;
use crate::models::repos::RepoRelease;
use crate::service::RepoService;
use crate::session::Session;

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

#[derive(Deserialize, Serialize, Clone, Debug, utoipa::ToSchema)]
pub struct CreateReleaseParams {
    pub tag_name: String,
    pub title: String,
    pub body: Option<String>,
    pub draft: Option<bool>,
    pub prerelease: Option<bool>,
    pub tag_id: Option<Uuid>,
}

#[derive(Deserialize, Serialize, Clone, Debug, utoipa::ToSchema)]
pub struct UpdateReleaseParams {
    pub title: Option<String>,
    pub body: Option<String>,
    pub draft: Option<bool>,
    pub prerelease: Option<bool>,
}

impl RepoService {
    pub async fn repo_releases(
        &self,
        ctx: &Session,
        wk_name: &str,
        repo_name: &str,
        limit: i64,
        offset: i64,
    ) -> Result<Vec<RepoRelease>, AppError> {
        let user_uid = ctx.user().ok_or(AppError::Unauthorized)?;
        let repo = self.resolve_repo(wk_name, repo_name).await?;
        let repo_id = repo.id;
        self.ensure_repo_readable(user_uid, &repo).await?;
        let (limit, offset) = clamp_limit_offset(limit, offset);
        sqlx::query_as::<_, RepoRelease>(
            "SELECT id, repo_id, tag_id, tag_name, title, body, draft, prerelease, author_id, published_at, created_at, updated_at, deleted_at FROM repo_release WHERE repo_id = $1 AND deleted_at IS NULL ORDER BY created_at DESC 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 repo_create_release(
        &self,
        ctx: &Session,
        wk_name: &str,
        repo_name: &str,
        params: CreateReleaseParams,
    ) -> Result<RepoRelease, AppError> {
        let user_uid = ctx.user().ok_or(AppError::Unauthorized)?;
        let repo = self.resolve_repo(wk_name, repo_name).await?;
        let repo_id = repo.id;
        self.ensure_repo_role_at_least(user_uid, &repo, Role::Member)
            .await?;
        let tag_name = required_text(params.tag_name, "tag_name")?;
        let title = required_text(params.title, "title")?;
        let now = chrono::Utc::now();
        let published_at = if params.draft.unwrap_or(false) {
            None
        } else {
            Some(now)
        };

        let mut txn = self
            .ctx
            .db
            .writer()
            .begin()
            .await
            .map_err(|_| AppError::TxnError)?;
        sqlx::query("SET LOCAL app.current_user_id = $1")
            .bind(user_uid)
            .execute(&mut *txn)
            .await
            .map_err(AppError::Database)?;

        let release = sqlx::query_as::<_, RepoRelease>(
            "INSERT INTO repo_release (id, repo_id, tag_id, tag_name, title, body, draft, prerelease, \
             author_id, published_at, created_at, updated_at) \
             VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $11) RETURNING id, repo_id, tag_id, tag_name, title, body, draft, prerelease, author_id, published_at, created_at, updated_at, deleted_at",
        )
        .bind(Uuid::now_v7())
        .bind(repo_id)
        .bind(params.tag_id)
        .bind(&tag_name)
        .bind(&title)
        .bind(&params.body)
        .bind(params.draft.unwrap_or(false))
        .bind(params.prerelease.unwrap_or(false))
        .bind(user_uid)
        .bind(published_at)
        .bind(now)
        .fetch_one(&mut *txn)
        .await
        .map_err(AppError::Database)?;

        sqlx::query(
            "UPDATE repo_stats SET releases_count = releases_count + 1, updated_at = $1 WHERE repo_id = $2",
        )
        .bind(now)
        .bind(repo_id)
        .execute(&mut *txn)
        .await
        .map_err(AppError::Database)?;

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

    pub async fn repo_update_release(
        &self,
        ctx: &Session,
        wk_name: &str,
        repo_name: &str,
        release_id: Uuid,
        params: UpdateReleaseParams,
    ) -> Result<RepoRelease, AppError> {
        let user_uid = ctx.user().ok_or(AppError::Unauthorized)?;
        let repo = self.resolve_repo(wk_name, repo_name).await?;
        let repo_id = repo.id;
        let actor_role = self
            .ensure_repo_role_at_least(user_uid, &repo, Role::Member)
            .await?;

        let current = sqlx::query_as::<_, RepoRelease>(
            "SELECT id, repo_id, tag_id, tag_name, title, body, draft, prerelease, author_id, published_at, created_at, updated_at, deleted_at FROM repo_release WHERE id = $1 AND repo_id = $2 AND deleted_at IS NULL",
        )
        .bind(release_id)
        .bind(repo_id)
        .fetch_optional(self.ctx.db.reader())
        .await
        .map_err(AppError::Database)?
        .ok_or(AppError::NotFound("release not found".into()))?;

        if crate::service::repo::util::role_level(actor_role)
            < crate::service::repo::util::role_level(Role::Admin)
            && current.author_id != user_uid
        {
            return Err(AppError::Unauthorized);
        }

        let title =
            merge_optional_text(params.title, Some(current.title.clone())).unwrap_or(current.title);
        let body = merge_optional_text(params.body, current.body);
        let draft = params.draft.unwrap_or(current.draft);
        let prerelease = params.prerelease.unwrap_or(current.prerelease);
        let now = chrono::Utc::now();

        let mut txn = self
            .ctx
            .db
            .writer()
            .begin()
            .await
            .map_err(|_| AppError::TxnError)?;
        sqlx::query("SET LOCAL app.current_user_id = $1")
            .bind(user_uid)
            .execute(&mut *txn)
            .await
            .map_err(AppError::Database)?;

        let result = sqlx::query_as::<_, RepoRelease>(
            "UPDATE repo_release SET title = $1, body = $2, draft = $3, prerelease = $4, \
             published_at = CASE WHEN $3 = false AND published_at IS NULL THEN $5 ELSE published_at END, \
             updated_at = $5 WHERE id = $6 AND repo_id = $7 RETURNING id, repo_id, tag_id, tag_name, title, body, draft, prerelease, author_id, published_at, created_at, updated_at, deleted_at",
        )
        .bind(&title)
        .bind(&body)
        .bind(draft)
        .bind(prerelease)
        .bind(now)
        .bind(release_id)
        .bind(repo_id)
        .fetch_one(&mut *txn)
        .await
        .map_err(AppError::Database)?;

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

    pub async fn repo_delete_release(
        &self,
        ctx: &Session,
        wk_name: &str,
        repo_name: &str,
        release_id: Uuid,
    ) -> Result<(), AppError> {
        let user_uid = ctx.user().ok_or(AppError::Unauthorized)?;
        let repo = self.resolve_repo(wk_name, repo_name).await?;
        let repo_id = repo.id;
        self.ensure_repo_role_at_least(user_uid, &repo, Role::Admin)
            .await?;
        let now = chrono::Utc::now();

        let mut txn = self
            .ctx
            .db
            .writer()
            .begin()
            .await
            .map_err(|_| AppError::TxnError)?;
        sqlx::query("SET LOCAL app.current_user_id = $1")
            .bind(user_uid)
            .execute(&mut *txn)
            .await
            .map_err(AppError::Database)?;

        let result = sqlx::query(
            "UPDATE repo_release SET deleted_at = $1, updated_at = $1 WHERE id = $2 AND repo_id = $3 AND deleted_at IS NULL",
        )
        .bind(now)
        .bind(release_id)
        .bind(repo_id)
        .execute(&mut *txn)
        .await
        .map_err(AppError::Database)?;
        ensure_affected(result.rows_affected(), "release not found")?;

        sqlx::query(
            "UPDATE repo_stats SET releases_count = GREATEST(releases_count - 1, 0), updated_at = $1 WHERE repo_id = $2",
        )
        .bind(now)
        .bind(repo_id)
        .execute(&mut *txn)
        .await
        .map_err(AppError::Database)?;

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