use crate::rpcgit::commit::types::{CommitInfo, ListCommitsOptions};
use serde::{Deserialize, Serialize};

use crate::context::facade::GitContext;
use crate::service::GitService;
use crate::service::cache::{self, IMMUTABLE_TTL};
use crate::share::errors::{GitError, map_baby};

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct LogListDto {
    pub commits: Vec<CommitInfo>,
    pub cursor: Option<String>,
    pub has_more: bool,
}

#[derive(Debug, Clone, Deserialize, utoipa::IntoParams)]
pub struct LogOptions {
    #[serde(default)]
    pub revision: Option<String>,
    #[serde(default)]
    pub limit: Option<u64>,
    #[serde(default)]
    pub skip: Option<u64>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct GraphNode {
    pub commit: CommitInfo,
    pub lanes: Vec<usize>,
}

const DEFAULT_LOG_LIMIT: u64 = 50;
const MAX_LOG_LIMIT: u64 = 200;

impl GitService {
    pub async fn log_list(
        &self,
        ctx: &GitContext,
        opts: LogOptions,
    ) -> Result<LogListDto, GitError> {
        let limit = opts
            .limit
            .unwrap_or(DEFAULT_LOG_LIMIT)
            .clamp(1, MAX_LOG_LIMIT);
        let skip = opts.skip.unwrap_or(0);
        let revision = opts.revision.clone().unwrap_or_else(|| "HEAD".to_string());
        let baby = self.baby(&ctx);
        let rev_oid = baby.rev_parse(&revision).await.map_err(map_baby)?;

        let key = format!(
            "repo.{}.log_list.{}:{}:{}",
            ctx.model.id, rev_oid, skip, limit
        );
        cache::cached_fetch(&ctx.cache, &key, IMMUTABLE_TTL, || async {
            let max = limit + skip + 1;
            let max_count = if max <= u32::MAX as u64 {
                Some(max as u32)
            } else {
                None
            };
            let commits = baby
                .list_commits(ListCommitsOptions {
                    revision: rev_oid.to_string(),
                    max_count,
                    ..Default::default()
                })
                .await
                .map_err(map_baby)?;
            let has_more = commits.len() > limit as usize + skip as usize;
            let mut page = commits;
            if page.len() > limit as usize + skip as usize {
                page.truncate(limit as usize + skip as usize);
            }
            let page = page.into_iter().skip(skip as usize).collect::<Vec<_>>();
            let cursor = page.last().map(|c| c.id.to_string());
            Ok(LogListDto {
                commits: page,
                cursor: if has_more { cursor } else { None },
                has_more,
            })
        })
        .await
    }
}