//! `milestone list|create|close` — manage milestones. Default action:
//! list.

use anyhow::{Context, Result};
use clap::{Args as ClapArgs, Subcommand};
use forgejo_api::structs::{
    CreateMilestoneOption, EditMilestoneOption, IssueGetMilestonesListQuery,
};
use serde_json::{Value, json};
use time::OffsetDateTime;
use time::format_description::well_known::Rfc3339;

use crate::client::{Client, index};
use crate::verbs::{print_json, rfc3339};

#[derive(ClapArgs)]
pub struct Args {
    #[command(subcommand)]
    action: Option<Action>,
}

#[derive(Subcommand)]
enum Action {
    /// List open milestones as JSON.
    List,
    /// Create a milestone, print {id,title}.
    Create {
        /// Milestone title.
        #[arg(long)]
        title: String,
        /// Description.
        #[arg(long)]
        desc: Option<String>,
        /// Due date YYYY-MM-DD.
        #[arg(long)]
        due: Option<String>,
    },
    /// Close a milestone by id.
    Close {
        /// Milestone id.
        id: u64,
    },
}

pub fn run(client: &Client, args: Args) -> Result<()> {
    let (owner, name) = client.owner_repo()?;
    match args.action.unwrap_or(Action::List) {
        Action::List => {
            let query = IssueGetMilestonesListQuery {
                state: Some("open".to_owned()),
                name: None,
            };
            let (_, milestones) = client
                .api()
                .issue_get_milestones_list(owner, name, query)
                .page_size(50)
                .send()?;
            let trimmed: Vec<Value> = milestones
                .iter()
                .map(|m| {
                    json!({
                        "id": m.id,
                        "title": m.title,
                        "open_issues": m.open_issues,
                        "closed_issues": m.closed_issues,
                        "due_on": rfc3339(m.due_on),
                        "description": m.description,
                    })
                })
                .collect();
            print_json(&Value::Array(trimmed))
        }
        Action::Create { title, desc, due } => {
            let due_on = due
                .filter(|s| !s.is_empty())
                .map(|d| {
                    OffsetDateTime::parse(&format!("{d}T00:00:00Z"), &Rfc3339)
                        .with_context(|| format!("milestone create: bad --due date {d:?}"))
                })
                .transpose()?;
            let payload = CreateMilestoneOption {
                description: desc.filter(|s| !s.is_empty()),
                due_on,
                state: None,
                title: Some(title),
            };
            let resp = client
                .api()
                .issue_create_milestone(owner, name, payload)
                .send()?;
            print_json(&json!({
                "id": resp.id,
                "title": resp.title,
            }))
        }
        Action::Close { id } => {
            let payload = EditMilestoneOption {
                description: None,
                due_on: None,
                state: Some("closed".to_owned()),
                title: None,
            };
            let resp = client
                .api()
                .issue_edit_milestone(owner, name, index(id)?, payload)
                .send()?;
            print_json(&json!({
                "id": resp.id,
                "title": resp.title,
                "state": resp.state,
            }))
        }
    }
}