//! `labels <number> [list|add|remove] [labels...]` — manage labels on
//! an issue or PR. Default action: list.

use anyhow::{Result, bail};
use clap::{Args as ClapArgs, Subcommand};
use forgejo_api::structs::{DeleteLabelsOption, IssueLabelsOption, IssueListLabelsQuery, Label};
use serde_json::json;

use crate::client::{Client, index};
use crate::verbs::print_json;

#[derive(ClapArgs)]
pub struct Args {
    /// Issue or PR number.
    pub(crate) number: u64,
    #[command(subcommand)]
    action: Option<Action>,
}

#[derive(Subcommand)]
enum Action {
    /// List labels (default when no action is given).
    List,
    /// Add labels by name.
    Add {
        /// Label names to add.
        labels: Vec<String>,
    },
    /// Remove labels by name.
    Remove {
        /// Label names to remove.
        labels: Vec<String>,
    },
}

pub fn run(client: &Client, args: Args) -> Result<()> {
    let (owner, name) = client.owner_repo()?;
    let idx = index(args.number)?;
    match args.action.unwrap_or(Action::List) {
        Action::List => {
            let labels = client.api().issue_get_labels(owner, name, idx).send()?;
            print_label_names(&labels);
        }
        Action::Add { labels } => {
            if labels.is_empty() {
                bail!("hive-forge labels add: pass at least one label name");
            }
            let all = repo_labels(client)?;
            let ids: Vec<serde_json::Value> = resolve_ids(&all, &labels)
                .into_iter()
                .map(|id| json!(id))
                .collect();
            let resp = client
                .api()
                .issue_add_label(
                    owner,
                    name,
                    idx,
                    IssueLabelsOption {
                        labels: Some(ids),
                        updated_at: None,
                    },
                )
                .send()?;
            print_label_names(&resp);
        }
        Action::Remove { labels } => {
            if labels.is_empty() {
                bail!("hive-forge labels remove: pass at least one label name");
            }
            let all = repo_labels(client)?;
            for label in &labels {
                if let Some(id) = lookup_id(&all, label) {
                    let _ = client
                        .api()
                        .issue_remove_label(
                            owner,
                            name,
                            idx,
                            &id.to_string(),
                            DeleteLabelsOption { updated_at: None },
                        )
                        .send();
                }
            }
            let labels = client.api().issue_get_labels(owner, name, idx).send()?;
            print_label_names(&labels);
        }
    }
    Ok(())
}

/// First page (100) of the repo's label set, for name → id resolution.
fn repo_labels(client: &Client) -> Result<Vec<Label>> {
    let (owner, name) = client.owner_repo()?;
    let (_, labels) = client
        .api()
        .issue_list_labels(owner, name, IssueListLabelsQuery::default())
        .page_size(100)
        .send()?;
    Ok(labels)
}

fn resolve_ids(all: &[Label], names: &[String]) -> Vec<i64> {
    names.iter().filter_map(|n| lookup_id(all, n)).collect()
}

fn lookup_id(all: &[Label], name: &str) -> Option<i64> {
    all.iter()
        .find(|l| l.name.as_deref() == Some(name))
        .and_then(|l| l.id)
}

fn print_label_names(labels: &[Label]) {
    let names: Vec<&str> = labels.iter().filter_map(|l| l.name.as_deref()).collect();
    let _ = print_json(&json!(names));
}