runtime-cli 0.1.0

//! `runtime pr` — list / view / create / comment / close / reopen /
//! checkout / merge / review.
//!
//! `checkout` fetches the PR's source branch via `git fetch` and
//! checks it out locally; `merge` calls `mergePullRequest`; `review`
//! calls `submitPullRequestReview` with the appropriate state enum.

use std::io::Write;

use anyhow::{anyhow, bail, Context, Result};
use clap::{Args, Subcommand};
use serde_json::{json, Value};

use crate::client::{self, Client};
use crate::commands::issue::resolve_repo;
use crate::commands::parse_slug;
use crate::editor;
use crate::output::{render_record, render_table, FormatChoice};

#[derive(Debug, Subcommand)]
pub enum PrCmd {
    List(ListArgs),
    View(ViewArgs),
    Create(CreateArgs),
    Comment(CommentArgs),
    Close(NumberArgs),
    Reopen(NumberArgs),
    /// Fetch and check out the PR's head branch locally.
    Checkout(NumberArgs),
    /// Merge a pull request.
    Merge(MergeArgs),
    /// Submit a review on a pull request.
    Review(ReviewArgs),
}

#[derive(Debug, Args)]
pub struct ListArgs {
    pub repo: String,
    #[arg(long, default_value = "open")]
    pub state: String,
    #[arg(long, default_value_t = false)]
    pub json: bool,
    #[arg(long, default_value_t = false)]
    pub tsv: bool,
}

#[derive(Debug, Args)]
pub struct ViewArgs {
    pub repo: String,
    pub number: i64,
    #[arg(long, default_value_t = false)]
    pub json: bool,
    #[arg(long, default_value_t = false)]
    pub tsv: bool,
}

#[derive(Debug, Args)]
pub struct CreateArgs {
    pub repo: String,
    #[arg(long, value_parser = clap::builder::NonEmptyStringValueParser::new())]
    pub title: String,
    #[arg(long)]
    pub body: Option<String>,
    /// Source branch (head).
    #[arg(long, value_parser = clap::builder::NonEmptyStringValueParser::new())]
    pub head: String,
    /// Target branch (base).
    #[arg(long, value_parser = clap::builder::NonEmptyStringValueParser::new())]
    pub base: String,
}

#[derive(Debug, Args)]
pub struct CommentArgs {
    pub repo: String,
    pub number: i64,
    #[arg(long)]
    pub body: Option<String>,
}

#[derive(Debug, Args)]
pub struct NumberArgs {
    pub repo: String,
    pub number: i64,
}

#[derive(Debug, Args)]
pub struct MergeArgs {
    pub repo: String,
    pub number: i64,
    /// One of `ff` (fast-forward), `squash`, `merge`, or `rebase`.
    #[arg(long, default_value = "merge")]
    pub strategy: String,
}

#[derive(Debug, Args)]
pub struct ReviewArgs {
    pub repo: String,
    pub number: i64,
    #[arg(long, conflicts_with_all = ["request_changes", "comment"])]
    pub approve: bool,
    #[arg(long, conflicts_with_all = ["approve", "comment"])]
    pub request_changes: bool,
    #[arg(long, conflicts_with_all = ["approve", "request_changes"])]
    pub comment: bool,
    #[arg(long, default_value = "")]
    pub body: String,
}

pub fn run(cmd: PrCmd) -> Result<()> {
    match cmd {
        PrCmd::List(a) => list(a),
        PrCmd::View(a) => view(a),
        PrCmd::Create(a) => create(a),
        PrCmd::Comment(a) => comment(a),
        PrCmd::Close(_) | PrCmd::Reopen(_) => {
            // The API surfaces close/reopen only for issues; PRs are
            // closed via merge or via the web UI. Surface a clear
            // error rather than 500.
            bail!("PR close/reopen is not exposed in this API version — use the web UI");
        }
        PrCmd::Checkout(a) => checkout(a),
        PrCmd::Merge(a) => merge(a),
        PrCmd::Review(a) => review(a),
    }
}

fn list(args: ListArgs) -> Result<()> {
    let (cli, _cfg) = client::authenticated()?;
    let (repo_id, _owner, _name) = resolve_repo(&cli, &args.repo)?;
    let data = cli.execute(PR_LIST, json!({ "id": repo_id }))?;
    let prs = data["pullRequests"].as_array().cloned().unwrap_or_default();
    let rows = pr_rows(&prs, &args.state);
    let fmt = FormatChoice {
        json: args.json,
        tsv: args.tsv,
    }
    .resolve();
    let out = render_table(&["#", "status", "title", "branches", "author"], &rows, fmt);
    std::io::stdout().lock().write_all(out.as_bytes())?;
    Ok(())
}

fn view(args: ViewArgs) -> Result<()> {
    let (cli, _cfg) = client::authenticated()?;
    let pr = resolve_pr(&cli, &args.repo, args.number)?;
    let pairs = vec![
        ("PR", format!("#{}", args.number)),
        ("Title", pr["title"].as_str().unwrap_or("").to_string()),
        ("Status", pr["status"].as_str().unwrap_or("").to_string()),
        (
            "Head",
            pr["sourceBranch"].as_str().unwrap_or("").to_string(),
        ),
        (
            "Base",
            pr["targetBranch"].as_str().unwrap_or("").to_string(),
        ),
        (
            "Author",
            pr["authorUsername"].as_str().unwrap_or("").to_string(),
        ),
        ("Body", pr["body"].as_str().unwrap_or("").to_string()),
    ];
    let fmt = FormatChoice {
        json: args.json,
        tsv: args.tsv,
    }
    .resolve();
    std::io::stdout()
        .lock()
        .write_all(render_record(&pairs, fmt).as_bytes())?;
    Ok(())
}

fn create(args: CreateArgs) -> Result<()> {
    let (cli, _cfg) = client::authenticated()?;
    let (repo_id, owner, name) = resolve_repo(&cli, &args.repo)?;
    let body = match args.body {
        Some(b) => b,
        None => editor::compose("")?,
    };
    let data = cli.execute(
        CREATE_PR,
        json!({
            "input": {
                "repositoryId": repo_id,
                "title": args.title,
                "body": body,
                "sourceBranch": args.head,
                "targetBranch": args.base,
            }
        }),
    )?;
    let number = data["createPullRequest"]["number"].as_i64().unwrap_or(0);
    writeln!(
        std::io::stdout().lock(),
        "Created PR #{} in {}/{}",
        number,
        owner,
        name
    )?;
    Ok(())
}

fn comment(args: CommentArgs) -> Result<()> {
    let (cli, _cfg) = client::authenticated()?;
    let pr = resolve_pr(&cli, &args.repo, args.number)?;
    let pr_id = pr["id"].as_str().ok_or_else(|| anyhow!("PR id missing"))?;
    let body = match args.body {
        Some(b) => b,
        None => editor::compose("")?,
    };
    cli.execute(
        ADD_PR_COMMENT,
        json!({ "input": { "pullRequestId": pr_id, "body": body } }),
    )?;
    writeln!(
        std::io::stdout().lock(),
        "Comment posted to {}#{}",
        args.repo,
        args.number
    )?;
    Ok(())
}

fn checkout(args: NumberArgs) -> Result<()> {
    let (cli, _cfg) = client::authenticated()?;
    let pr = resolve_pr(&cli, &args.repo, args.number)?;
    let head_branch = pr["sourceBranch"]
        .as_str()
        .ok_or_else(|| anyhow!("PR has no sourceBranch"))?;
    let (owner, name) = parse_slug(&args.repo)?;
    let url = format!("{}/{}/{}.git", cli.host(), owner, name);
    let status = std::process::Command::new("git")
        .arg("fetch")
        .arg(&url)
        .arg(format!("{head_branch}:{head_branch}"))
        .status()
        .context("run `git fetch`")?;
    if !status.success() {
        bail!("git fetch exited with status {status}");
    }
    let status = std::process::Command::new("git")
        .arg("checkout")
        .arg(head_branch)
        .status()
        .context("run `git checkout`")?;
    if !status.success() {
        bail!("git checkout exited with status {status}");
    }
    Ok(())
}

fn merge(args: MergeArgs) -> Result<()> {
    let (cli, _cfg) = client::authenticated()?;
    let pr = resolve_pr(&cli, &args.repo, args.number)?;
    let pr_id = pr["id"].as_str().ok_or_else(|| anyhow!("PR id missing"))?;
    let strategy = merge_strategy_arg(&args.strategy)?;
    cli.execute(
        MERGE_PR,
        json!({ "input": { "pullRequestId": pr_id, "strategy": strategy } }),
    )?;
    writeln!(
        std::io::stdout().lock(),
        "Merged PR {}#{} ({})",
        args.repo,
        args.number,
        strategy
    )?;
    Ok(())
}

fn review(args: ReviewArgs) -> Result<()> {
    let (cli, _cfg) = client::authenticated()?;
    let pr = resolve_pr(&cli, &args.repo, args.number)?;
    let pr_id = pr["id"].as_str().ok_or_else(|| anyhow!("PR id missing"))?;
    let state = review_state_arg(&args)?;
    cli.execute(
        SUBMIT_REVIEW,
        json!({
            "input": {
                "pullRequestId": pr_id,
                "state": state,
                "body": args.body,
            }
        }),
    )?;
    writeln!(
        std::io::stdout().lock(),
        "Submitted {} review on {}#{}",
        state,
        args.repo,
        args.number
    )?;
    Ok(())
}

fn merge_strategy_arg(strategy: &str) -> Result<&'static str> {
    match strategy.to_ascii_lowercase().as_str() {
        "ff" | "fast-forward" | "fast_forward" => Ok("FAST_FORWARD"),
        "merge" | "merge-commit" | "merge_commit" => Ok("MERGE_COMMIT"),
        "squash" => Ok("SQUASH"),
        "rebase" => Ok("REBASE"),
        other => bail!("unknown merge strategy `{other}` (expected ff/merge/squash/rebase)"),
    }
}

fn review_state_arg(args: &ReviewArgs) -> Result<&'static str> {
    match (args.approve, args.request_changes, args.comment) {
        (true, false, false) => Ok("APPROVED"),
        (false, true, false) => Ok("CHANGES_REQUESTED"),
        (false, false, true) => Ok("COMMENTED"),
        (false, false, false) => bail!("pass one of --approve / --request-changes / --comment"),
        _ => bail!("--approve / --request-changes / --comment are mutually exclusive"),
    }
}

fn resolve_pr(cli: &Client, slug: &str, number: i64) -> Result<Value> {
    let (repo_id, owner, name) = resolve_repo(cli, slug)?;
    let data = cli.execute(PR_LIST, json!({ "id": repo_id }))?;
    let prs = data["pullRequests"].as_array().cloned().unwrap_or_default();
    prs.into_iter()
        .find(|p| p["number"].as_i64() == Some(number))
        .ok_or_else(|| anyhow!("no PR #{} in {}/{}", number, owner, name))
}

fn pr_rows(prs: &[Value], state: &str) -> Vec<Vec<String>> {
    let state_filter = state.to_ascii_lowercase();
    prs.iter()
        .filter(|p| match state_filter.as_str() {
            "all" => true,
            "closed" => matches!(p["status"].as_str(), Some("CLOSED")),
            "merged" => matches!(p["status"].as_str(), Some("MERGED")),
            _ => matches!(p["status"].as_str(), Some("OPEN")),
        })
        .map(|p| {
            vec![
                format!("#{}", p["number"].as_i64().unwrap_or(0)),
                p["status"].as_str().unwrap_or("").to_string(),
                p["title"].as_str().unwrap_or("").to_string(),
                format!(
                    "{} → {}",
                    p["sourceBranch"].as_str().unwrap_or(""),
                    p["targetBranch"].as_str().unwrap_or("")
                ),
                p["authorUsername"].as_str().unwrap_or("").to_string(),
            ]
        })
        .collect()
}

const PR_LIST: &str = "query($id: UUID!) { \
    pullRequests(repositoryId: $id) { \
        id number title status sourceBranch targetBranch authorUsername body updatedAt \
    } \
}";

const CREATE_PR: &str = "mutation($input: CreatePullRequestInput!) { \
    createPullRequest(input: $input) { id number } \
}";

const ADD_PR_COMMENT: &str = "mutation($input: AddPullRequestCommentInput!) { \
    addPullRequestComment(input: $input) { id } \
}";

const MERGE_PR: &str = "mutation($input: MergePullRequestInput!) { \
    mergePullRequest(input: $input) { id status } \
}";

const SUBMIT_REVIEW: &str = "mutation($input: SubmitPullRequestReviewInput!) { \
    submitPullRequestReview(input: $input) { id state } \
}";

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn merge_strategy_arg_accepts_documented_aliases() {
        let cases = [
            ("ff", "FAST_FORWARD"),
            ("fast-forward", "FAST_FORWARD"),
            ("fast_forward", "FAST_FORWARD"),
            ("merge", "MERGE_COMMIT"),
            ("merge-commit", "MERGE_COMMIT"),
            ("merge_commit", "MERGE_COMMIT"),
            ("squash", "SQUASH"),
            ("rebase", "REBASE"),
            ("SQUASH", "SQUASH"),
        ];

        for (input, expected) in cases {
            assert_eq!(merge_strategy_arg(input).unwrap(), expected);
        }
    }

    #[test]
    fn merge_strategy_arg_rejects_unknown_values() {
        let err = merge_strategy_arg("ours").unwrap_err().to_string();
        assert!(err.contains("unknown merge strategy `ours`"));
    }

    #[test]
    fn review_state_arg_requires_exactly_one_state_flag() {
        let approved = ReviewArgs {
            repo: "alice/r1".into(),
            number: 7,
            approve: true,
            request_changes: false,
            comment: false,
            body: String::new(),
        };
        assert_eq!(review_state_arg(&approved).unwrap(), "APPROVED");

        let changes = ReviewArgs {
            request_changes: true,
            approve: false,
            ..approved
        };
        assert_eq!(review_state_arg(&changes).unwrap(), "CHANGES_REQUESTED");

        let commented = ReviewArgs {
            comment: true,
            request_changes: false,
            ..changes
        };
        assert_eq!(review_state_arg(&commented).unwrap(), "COMMENTED");

        let missing = ReviewArgs {
            comment: false,
            ..commented
        };
        assert!(review_state_arg(&missing)
            .unwrap_err()
            .to_string()
            .contains("pass one of"));

        let multiple = ReviewArgs {
            approve: true,
            comment: true,
            ..missing
        };
        assert!(review_state_arg(&multiple)
            .unwrap_err()
            .to_string()
            .contains("mutually exclusive"));
    }

    #[test]
    fn pr_rows_filters_by_state_and_formats_branch_pair() {
        let prs = vec![
            serde_json::json!({
                "number": 1,
                "status": "OPEN",
                "title": "Add single-box CI",
                "sourceBranch": "ci-local",
                "targetBranch": "main",
                "authorUsername": "bri"
            }),
            serde_json::json!({
                "number": 2,
                "status": "CLOSED",
                "title": "Old deploy spike",
                "sourceBranch": "deploy-spike",
                "targetBranch": "main",
                "authorUsername": "sam"
            }),
            serde_json::json!({
                "number": 3,
                "status": "MERGED",
                "title": "Registry auth",
                "sourceBranch": "registry-auth",
                "targetBranch": "main",
                "authorUsername": "alex"
            }),
        ];

        assert_eq!(
            pr_rows(&prs, "open"),
            vec![vec![
                "#1",
                "OPEN",
                "Add single-box CI",
                "ci-local → main",
                "bri"
            ]]
        );
        assert_eq!(
            pr_rows(&prs, "closed"),
            vec![vec![
                "#2",
                "CLOSED",
                "Old deploy spike",
                "deploy-spike → main",
                "sam"
            ]]
        );
        assert_eq!(
            pr_rows(&prs, "merged"),
            vec![vec![
                "#3",
                "MERGED",
                "Registry auth",
                "registry-auth → main",
                "alex"
            ]]
        );
        assert_eq!(pr_rows(&prs, "all").len(), 3);
    }

    #[test]
    fn pr_rows_defaults_missing_fields_to_empty_values() {
        let prs = vec![serde_json::json!({})];

        assert_eq!(pr_rows(&prs, "all"), vec![vec!["#0", "", "", " → ", ""]]);
    }
}