travelagent-forge-github 1.11.1

use std::net::IpAddr;
use std::time::Duration;

use async_trait::async_trait;
use reqwest::{Client, header};
use serde::de::DeserializeOwned;
use url::{Host, Url};

use travelagent_core::error::{Result, TrvError};
use travelagent_core::forge::{
    ForgeComments, ForgeMerge, ForgeReactions, ForgeRead, ForgeReview, ForgeType, ForgeWarnHandler,
    MergeMethod, MergeableStatus, NewComment, NewReview, Permissions, PrId, PrListFilter,
    PrListItem, PrMetadata, PrState, ReactionContent, ReactionTarget, RemoteComment, ReviewThread,
    ReviewVerdict, User,
};
use travelagent_core::model::{DiffFile, FileStatus, LineSide};
use travelagent_core::vcs::CommitInfo;
use travelagent_core::vcs::diff_parser::parse_patch_hunks;

use crate::auth;
use crate::types::{
    GhCommit, GhCommitDetail2, GhFile, GhIssueComment, GhPullRequest, GhPullRequestListItem,
    GhRepo, GhRepoPermissions, GhReviewComment, GhUser,
};

/// Maximum number of bytes from a response body we retain when building error
/// messages. Bodies beyond this are truncated so we never splat multi-megabyte
/// payloads (potentially containing secrets) into logs.
const MAX_ERROR_BODY_BYTES: usize = 2 * 1024;

/// Hard connect timeout for outbound HTTP requests.
const CONNECT_TIMEOUT: Duration = Duration::from_secs(10);
/// Hard overall request timeout. Protects the TUI from hanging on slow forges.
const REQUEST_TIMEOUT: Duration = Duration::from_secs(30);

pub struct GitHubForge {
    client: Client,
    base_url: String,
    /// Optional callback for non-fatal warnings (e.g. pagination truncation).
    /// When `None`, warnings fall back to stderr via `eprintln!`. The TUI
    /// installs one of these via `with_warn_handler` so warnings reach the
    /// status bar + error-log ring instead of garbling the alternate screen.
    warn_handler: Option<ForgeWarnHandler>,
}

impl GitHubForge {
    pub fn new() -> Result<Self> {
        Self::with_base_url("https://api.github.com")
    }

    /// Validate + normalize a base URL. Rejects non-`https` schemes and
    /// hostnames that resolve (syntactically) to loopback, private, link-local,
    /// or unspecified IP literals. Pass `allow_insecure = true` to bypass the
    /// scheme and IP-literal checks (useful for tests hitting `http://127.0.0.1`
    /// mock servers).
    fn validate_base_url(base_url: &str, allow_insecure: bool) -> Result<String> {
        let parsed = Url::parse(base_url)
            .map_err(|_| TrvError::AuthError("base_url is not a valid URL".to_string()))?;

        if !allow_insecure && parsed.scheme() != "https" {
            return Err(TrvError::AuthError(
                "base_url must use https:// scheme".to_string(),
            ));
        }
        if parsed.scheme() != "https" && parsed.scheme() != "http" {
            return Err(TrvError::AuthError(
                "base_url must use http:// or https:// scheme".to_string(),
            ));
        }

        if !allow_insecure {
            match parsed.host() {
                Some(Host::Ipv4(ip)) => {
                    let ip = IpAddr::V4(ip);
                    if is_blocked_ip(&ip) {
                        return Err(TrvError::AuthError(
                            "base_url host resolves to a private, loopback, or link-local address"
                                .to_string(),
                        ));
                    }
                }
                Some(Host::Ipv6(ip)) => {
                    let ip = IpAddr::V6(ip);
                    if is_blocked_ip(&ip) {
                        return Err(TrvError::AuthError(
                            "base_url host resolves to a private, loopback, or link-local address"
                                .to_string(),
                        ));
                    }
                }
                Some(Host::Domain(_)) => {}
                None => {
                    return Err(TrvError::AuthError(
                        "base_url must include a host".to_string(),
                    ));
                }
            }
        }

        // Return the original (trimmed) string so downstream path joins continue
        // to work against the caller's exact formatting (e.g. GHE `/api/v3`).
        Ok(base_url.trim_end_matches('/').to_string())
    }

    pub fn with_base_url(base_url: &str) -> Result<Self> {
        let token = auth::resolve_token()?;
        Self::with_token(base_url, token)
    }

    pub fn with_token(base_url: &str, token: String) -> Result<Self> {
        // Production builder: require https + public host.
        Self::with_token_validated(base_url, token, false)
    }

    /// Like [`with_token`] but allows the caller to opt into insecure hosts
    /// (non-https, loopback/private IP literals). Production callers should
    /// stick with [`with_token`].
    pub fn with_token_insecure(base_url: &str, token: String) -> Result<Self> {
        Self::with_token_validated(base_url, token, true)
    }

    fn with_token_validated(base_url: &str, token: String, allow_insecure: bool) -> Result<Self> {
        let normalized_base = Self::validate_base_url(base_url, allow_insecure)?;

        let mut headers = header::HeaderMap::new();
        headers.insert(
            header::ACCEPT,
            header::HeaderValue::from_static("application/vnd.github+json"),
        );
        headers.insert(
            "X-GitHub-Api-Version",
            header::HeaderValue::from_static("2022-11-28"),
        );
        headers.insert(
            header::AUTHORIZATION,
            format!("Bearer {token}").parse().map_err(|_| {
                TrvError::AuthError(
                    "token contains invalid header bytes; check GITHUB_TOKEN".to_string(),
                )
            })?,
        );
        headers.insert(
            header::USER_AGENT,
            header::HeaderValue::from_static("travelagent"),
        );

        // Set overall + connect timeouts to bound worst-case latency.
        let client = Client::builder()
            .default_headers(headers)
            .timeout(REQUEST_TIMEOUT)
            .connect_timeout(CONNECT_TIMEOUT)
            .build()
            .map_err(|e| TrvError::ForgeApi(format!("Failed to create HTTP client: {e}")))?;

        Ok(Self {
            client,
            base_url: normalized_base,
            warn_handler: None,
        })
    }

    /// Install a callback to receive non-fatal warnings (e.g. pagination
    /// truncation). Without one, warnings fall back to `eprintln!`.
    pub fn with_warn_handler(mut self, handler: ForgeWarnHandler) -> Self {
        self.warn_handler = Some(handler);
        self
    }

    /// Emit a non-fatal warning through the installed callback, or fall back
    /// to `eprintln!` when no callback is set.
    fn emit_warning(&self, msg: String) {
        if let Some(ref handler) = self.warn_handler {
            handler(msg);
        } else {
            eprintln!("{msg}");
        }
    }

    async fn get<T: DeserializeOwned>(&self, path: &str) -> Result<T> {
        let url = format!("{}{}", self.base_url, path);
        let resp = self
            .client
            .get(&url)
            .send()
            .await
            .map_err(|e| TrvError::ForgeApi(format!("Request failed: {e}")))?;

        let resp = Self::check_response(resp, &url).await?;

        resp.json()
            .await
            .map_err(|e| TrvError::ForgeApi(format!("Failed to parse response: {e}")))
    }

    async fn post<T: DeserializeOwned>(&self, path: &str, body: &serde_json::Value) -> Result<T> {
        let url = format!("{}{}", self.base_url, path);
        let resp = self
            .client
            .post(&url)
            .json(body)
            .send()
            .await
            .map_err(|e| TrvError::ForgeApi(format!("Request failed: {e}")))?;

        let resp = Self::check_response(resp, &url).await?;

        resp.json()
            .await
            .map_err(|e| TrvError::ForgeApi(format!("Failed to parse response: {e}")))
    }

    async fn post_no_content(&self, path: &str, body: &serde_json::Value) -> Result<()> {
        let url = format!("{}{}", self.base_url, path);
        let resp = self
            .client
            .post(&url)
            .json(body)
            .send()
            .await
            .map_err(|e| TrvError::ForgeApi(format!("Request failed: {e}")))?;

        Self::check_response(resp, &url).await?;
        Ok(())
    }

    async fn patch<T: DeserializeOwned>(&self, path: &str, body: &serde_json::Value) -> Result<T> {
        let url = format!("{}{}", self.base_url, path);
        let resp = self
            .client
            .patch(&url)
            .json(body)
            .send()
            .await
            .map_err(|e| TrvError::ForgeApi(format!("Request failed: {e}")))?;

        let resp = Self::check_response(resp, &url).await?;

        resp.json()
            .await
            .map_err(|e| TrvError::ForgeApi(format!("Failed to parse response: {e}")))
    }

    async fn put_no_content(&self, path: &str, body: &serde_json::Value) -> Result<()> {
        let url = format!("{}{}", self.base_url, path);
        let resp = self
            .client
            .put(&url)
            .json(body)
            .send()
            .await
            .map_err(|e| TrvError::ForgeApi(format!("Request failed: {e}")))?;

        Self::check_response(resp, &url).await?;
        Ok(())
    }

    async fn delete(&self, path: &str) -> Result<()> {
        let url = format!("{}{}", self.base_url, path);
        let resp = self
            .client
            .delete(&url)
            .send()
            .await
            .map_err(|e| TrvError::ForgeApi(format!("Request failed: {e}")))?;

        Self::check_response(resp, &url).await?;
        Ok(())
    }

    /// Non-consuming status check for use in `get_all_pages` where we need to
    /// read headers (Link) from the response before consuming the body.
    fn check_response_status(resp: &reqwest::Response, url: &str) -> Result<()> {
        match resp.status().as_u16() {
            200..=299 => Ok(()),
            401 => Err(TrvError::AuthError(
                "GitHub API authentication failed".into(),
            )),
            403 if resp
                .headers()
                .get("x-ratelimit-remaining")
                .and_then(|v| v.to_str().ok())
                == Some("0") =>
            {
                Err(TrvError::RateLimited)
            }
            404 => Err(TrvError::NotFound(url.to_string())),
            status => Err(TrvError::ForgeApi(format!("GitHub API {status} for {url}"))),
        }
    }

    async fn check_response(resp: reqwest::Response, url: &str) -> Result<reqwest::Response> {
        match resp.status().as_u16() {
            200..=299 => Ok(resp),
            401 => Err(TrvError::AuthError(
                "GitHub API authentication failed".into(),
            )),
            403 if resp
                .headers()
                .get("x-ratelimit-remaining")
                .and_then(|v| v.to_str().ok())
                == Some("0") =>
            {
                Err(TrvError::RateLimited)
            }
            404 => {
                let body = read_error_body(resp).await;
                let body = sanitize_error_body(&body);
                Err(TrvError::NotFound(format!("{url}: {body}")))
            }
            status => {
                let body = read_error_body(resp).await;
                let body = sanitize_error_body(&body);
                Err(TrvError::ForgeApi(format!(
                    "GitHub API {status} for {url}: {body}"
                )))
            }
        }
    }

    async fn get_all_pages<T: DeserializeOwned>(&self, path: &str) -> Result<Vec<T>> {
        const MAX_PAGES: usize = 50;
        let mut all: Vec<T> = Vec::new();
        let mut page_count: usize = 0;
        let mut url = if path.contains('?') {
            format!("{}{}&per_page=100", self.base_url, path)
        } else {
            format!("{}{}?per_page=100", self.base_url, path)
        };
        loop {
            if page_count >= MAX_PAGES {
                // Phase A: surface silent truncation via the installed warn
                // handler (TUI routes this into the status bar + error-log
                // ring). Without a handler we fall back to stderr so CLI-only
                // paths still see the message.
                self.emit_warning(format!(
                    "trv: warning: GitHub pagination hit MAX_PAGES={MAX_PAGES} limit for {path}; results may be truncated"
                ));
                break;
            }
            page_count += 1;

            let resp = self
                .client
                .get(&url)
                .send()
                .await
                .map_err(|e| TrvError::ForgeApi(format!("Request failed: {e}")))?;

            Self::check_response_status(&resp, &url)?;

            let next_url = resp
                .headers()
                .get("link")
                .and_then(|v| v.to_str().ok())
                .and_then(parse_next_link);

            let page: Vec<T> = resp
                .json()
                .await
                .map_err(|e| TrvError::ForgeApi(format!("Failed to parse response: {e}")))?;
            all.extend(page);

            match next_url {
                Some(next) => url = next,
                None => break,
            }
        }
        Ok(all)
    }

    /// Paginate `path` up to `limit` items, using `per_page` up to 100 per
    /// request. Stops as soon as the accumulated count reaches `limit` or the
    /// next Link header is absent. Returns at most `limit` items.
    async fn get_pages_up_to<T: DeserializeOwned>(
        &self,
        path: &str,
        limit: usize,
    ) -> Result<Vec<T>> {
        const MAX_PAGES: usize = 50;
        let per_page = limit.clamp(1, 100);
        let mut all: Vec<T> = Vec::new();
        let mut page_count: usize = 0;
        let mut url = if path.contains('?') {
            format!("{}{}&per_page={}", self.base_url, path, per_page)
        } else {
            format!("{}{}?per_page={}", self.base_url, path, per_page)
        };
        loop {
            if page_count >= MAX_PAGES {
                self.emit_warning(format!(
                    "trv: warning: GitHub pagination hit MAX_PAGES={MAX_PAGES} limit for {path}; results may be truncated"
                ));
                break;
            }
            page_count += 1;

            let resp = self
                .client
                .get(&url)
                .send()
                .await
                .map_err(|e| TrvError::ForgeApi(format!("Request failed: {e}")))?;

            Self::check_response_status(&resp, &url)?;

            let next_url = resp
                .headers()
                .get("link")
                .and_then(|v| v.to_str().ok())
                .and_then(parse_next_link);

            let page: Vec<T> = resp
                .json()
                .await
                .map_err(|e| TrvError::ForgeApi(format!("Failed to parse response: {e}")))?;
            all.extend(page);

            if all.len() >= limit {
                all.truncate(limit);
                break;
            }

            match next_url {
                Some(next) => url = next,
                None => break,
            }
        }
        Ok(all)
    }

    /// GraphQL endpoint URL. For github.com the REST base is https://api.github.com
    /// and GraphQL is at https://api.github.com/graphql. For GHE, the REST base is
    /// https://HOSTNAME/api/v3 and GraphQL is https://HOSTNAME/api/graphql.
    fn graphql_url(&self) -> String {
        if self.base_url.ends_with("/api/v3") {
            // GHE: https://HOSTNAME/api/v3 -> https://HOSTNAME/api/graphql
            format!("{}/graphql", self.base_url.trim_end_matches("/v3"))
        } else {
            // github.com: https://api.github.com -> https://api.github.com/graphql
            format!("{}/graphql", self.base_url)
        }
    }

    async fn graphql_with_vars(
        &self,
        query: &str,
        variables: serde_json::Value,
    ) -> Result<serde_json::Value> {
        let url = self.graphql_url();
        let resp = self
            .client
            .post(&url)
            .json(&serde_json::json!({ "query": query, "variables": variables }))
            .send()
            .await
            .map_err(|e| TrvError::ForgeApi(format!("GraphQL request failed: {e}")))?;

        let resp = Self::check_response(resp, &url).await?;

        let body: serde_json::Value = resp
            .json()
            .await
            .map_err(|e| TrvError::ForgeApi(format!("GraphQL parse error: {e}")))?;

        if let Some(errors) = body.get("errors") {
            return Err(TrvError::ForgeApi(format!("GraphQL errors: {errors}")));
        }

        Ok(body)
    }
}

/// Return true when `ip` falls into a range we refuse to reach from the forge
/// client (SSRF hardening): loopback, private (RFC1918), link-local, or
/// unspecified addresses.
fn is_blocked_ip(ip: &IpAddr) -> bool {
    if ip.is_loopback() || ip.is_unspecified() {
        return true;
    }
    match ip {
        IpAddr::V4(v4) => {
            v4.is_private()
                || v4.is_link_local()
                || v4.is_broadcast()
                // 100.64.0.0/10 — RFC 6598 carrier-grade NAT
                || (v4.octets()[0] == 100 && (v4.octets()[1] & 0xc0) == 64)
        }
        IpAddr::V6(v6) => {
            // Unique local (fc00::/7)
            (v6.segments()[0] & 0xfe00) == 0xfc00
                // Link-local (fe80::/10)
                || (v6.segments()[0] & 0xffc0) == 0xfe80
                // IPv4-mapped / IPv4-compatible — re-check the embedded v4.
                || v6
                    .to_ipv4_mapped()
                    .is_some_and(|v4| is_blocked_ip(&IpAddr::V4(v4)))
        }
    }
}

/// Read the body of an error response, surfacing the read failure instead
/// of silently returning an empty string. Previously `check_response`
/// called `resp.text().await.unwrap_or_default()`, which dropped the
/// underlying IO error and left `sanitize_error_body` operating on "" —
/// users saw "GitHub API 500 for <url>: " with no hint at what went
/// wrong. grok-4-20-thinking flagged this in the 2026-05-02 crew review.
async fn read_error_body(resp: reqwest::Response) -> String {
    match resp.text().await {
        Ok(body) => body,
        Err(e) => format!("<body read failed: {e}>"),
    }
}

/// Strip lines that look like credential headers (Authorization, Private-Token,
/// X-*-Token, etc.) and truncate to [`MAX_ERROR_BODY_BYTES`]. We never want a
/// forge echoing a request header into an error body to leak a token into
/// TUI/log output.
fn sanitize_error_body(body: &str) -> String {
    // Filter credential-bearing lines first, so truncation operates on the
    // scrubbed text (avoids a case where we truncate right before a secret
    // header and happen to keep it).
    let filtered: String = body
        .lines()
        .filter(|line| !line_looks_like_credential_header(line))
        .collect::<Vec<_>>()
        .join("\n");

    if filtered.len() <= MAX_ERROR_BODY_BYTES {
        filtered
    } else {
        // Truncate on a char boundary to avoid splitting a multi-byte UTF-8
        // scalar in half.
        let mut end = MAX_ERROR_BODY_BYTES;
        while end > 0 && !filtered.is_char_boundary(end) {
            end -= 1;
        }
        let mut out = filtered[..end].to_string();
        out.push_str("... [truncated]");
        out
    }
}

/// True if `line` matches `(?i)^(authorization|private-token|x-.*-token)\s*:`.
fn line_looks_like_credential_header(line: &str) -> bool {
    let colon = match line.find(':') {
        Some(i) => i,
        None => return false,
    };
    let name = line[..colon].trim().to_ascii_lowercase();
    if name.is_empty() {
        return false;
    }
    if name == "authorization" || name == "private-token" {
        return true;
    }
    if let Some(rest) = name.strip_prefix("x-") {
        // Anything ending in "-token" or exactly "token".
        return rest == "token" || rest.ends_with("-token");
    }
    false
}

fn parse_next_link(link_header: &str) -> Option<String> {
    for part in link_header.split(',') {
        let trimmed = part.trim();
        if trimmed.ends_with("rel=\"next\"")
            && let Some(url) = trimmed.strip_suffix("; rel=\"next\"")
        {
            return Some(url.trim().trim_matches('<').trim_matches('>').to_string());
        }
    }
    None
}

// --- Conversion helpers ---

fn parse_datetime(s: &str) -> Result<chrono::DateTime<chrono::Utc>> {
    chrono::DateTime::parse_from_rfc3339(s)
        .map(|dt| dt.with_timezone(&chrono::Utc))
        .map_err(|e| TrvError::ForgeApi(format!("Invalid datetime '{s}': {e}")))
}

/// Bounded GET that paginates up to `limit` items or `MAX_PAGES` pages.
///
/// Returns at most `limit` items, stopping as soon as that threshold is met
/// even if more pages exist. Used by `list_prs` so callers can ask for a
/// small number (default 30) without us fetching everything.
fn default_list_prs_max() -> u32 {
    30
}

fn cap_list_prs_max(m: u32) -> u32 {
    // Cap at 100 per spec; also clamp to at least 1.
    m.clamp(1, 100)
}

fn convert_pr_list_item(
    gh: GhPullRequestListItem,
    current_user_login: Option<&str>,
) -> Result<PrListItem> {
    let state = if gh.merged_at.is_some() {
        PrState::Merged
    } else if gh.state == "closed" {
        PrState::Closed
    } else {
        PrState::Open
    };
    let has_review_requested_from_me = match current_user_login {
        Some(me) => gh.requested_reviewers.iter().any(|u| u.login == me),
        None => false,
    };
    let comment_count = {
        let review = gh.review_comments.unwrap_or(0);
        let issue = gh.comments.unwrap_or(0);
        u32::try_from(review.saturating_add(issue)).unwrap_or(u32::MAX)
    };
    let assignees = gh.assignees.iter().map(|u| u.login.clone()).collect();
    let reviewers = gh
        .requested_reviewers
        .iter()
        .map(|u| u.login.clone())
        .collect();
    Ok(PrListItem {
        number: gh.number,
        title: gh.title,
        author: gh.user.login,
        state,
        is_draft: gh.draft.unwrap_or(false),
        base_branch: gh.base.ref_name,
        head_branch: gh.head.ref_name,
        updated_at: parse_datetime(&gh.updated_at)?,
        comment_count,
        has_review_requested_from_me,
        assignees,
        reviewers,
    })
}

fn convert_pr(gh: GhPullRequest) -> Result<PrMetadata> {
    let state = if gh.merged_at.is_some() {
        PrState::Merged
    } else if gh.state == "closed" {
        PrState::Closed
    } else {
        PrState::Open
    };

    let mergeable = gh.mergeable_state.as_deref().map(|s| match s {
        "clean" => MergeableStatus::Clean,
        "unstable" => MergeableStatus::Unstable,
        "behind" => MergeableStatus::Behind,
        "blocked" => MergeableStatus::Blocked,
        "dirty" => MergeableStatus::Dirty,
        "draft" => MergeableStatus::Draft,
        _ => MergeableStatus::Unknown,
    });

    Ok(PrMetadata {
        title: gh.title,
        body: gh.body.unwrap_or_default(),
        author: gh.user.login,
        state,
        base_branch: gh.base.ref_name,
        head_branch: gh.head.ref_name,
        head_sha: gh.head.sha,
        created_at: parse_datetime(&gh.created_at)?,
        mergeable,
        is_draft: gh.draft.unwrap_or(false),
    })
}

fn convert_commit(gh: GhCommit) -> Result<CommitInfo> {
    let short_id = if gh.sha.len() >= 7 {
        gh.sha[..7].to_string()
    } else {
        gh.sha.clone()
    };
    let (summary, body) = match gh.commit.message.split_once('\n') {
        Some((s, b)) => (s.to_string(), Some(b.trim().to_string())),
        None => (gh.commit.message.clone(), None),
    };
    let author = gh.author.map(|u| u.login).unwrap_or(gh.commit.author.name);
    let time = match gh.commit.author.date {
        Some(d) => parse_datetime(&d)?,
        None => chrono::Utc::now(),
    };

    Ok(CommitInfo {
        id: gh.sha,
        short_id,
        branch_name: None,
        summary,
        body,
        author,
        time,
    })
}

fn convert_review_comment(gh: GhReviewComment) -> Result<RemoteComment> {
    let side = gh.side.as_deref().map(|s| match s {
        "LEFT" => LineSide::Old,
        _ => LineSide::New,
    });

    Ok(RemoteComment {
        id: gh.id,
        author: gh.user.login,
        body: gh.body,
        path: Some(gh.path),
        line: gh.line,
        side,
        created_at: parse_datetime(&gh.created_at)?,
        in_reply_to: gh.in_reply_to_id,
    })
}

/// Parse GitHub's per-file `patch` field into DiffFile structures.
///
/// GitHub returns a `patch` string per file that looks like a unified diff
/// without the `---`/`+++` file headers. Each hunk starts with `@@`.
fn parse_gh_files(gh_files: Vec<GhFile>) -> Vec<DiffFile> {
    gh_files.into_iter().map(parse_single_gh_file).collect()
}

fn parse_single_gh_file(gh: GhFile) -> DiffFile {
    let status = match gh.status.as_str() {
        "added" => FileStatus::Added,
        "removed" => FileStatus::Deleted,
        "renamed" => FileStatus::Renamed,
        "copied" => FileStatus::Copied,
        _ => FileStatus::Modified,
    };

    let old_path = match status {
        FileStatus::Added => None,
        FileStatus::Renamed | FileStatus::Copied => {
            gh.previous_filename.map(std::path::PathBuf::from)
        }
        _ => Some(std::path::PathBuf::from(&gh.filename)),
    };

    let new_path = match status {
        FileStatus::Deleted => None,
        _ => Some(std::path::PathBuf::from(&gh.filename)),
    };

    let hunks = match &gh.patch {
        Some(patch) if !patch.is_empty() => parse_patch_hunks(patch),
        _ => Vec::new(),
    };

    let is_binary = gh.patch.is_none()
        && gh.additions == 0
        && gh.deletions == 0
        && status != FileStatus::Renamed
        && status != FileStatus::Copied;
    let is_too_large = gh.patch.is_none() && (gh.additions > 0 || gh.deletions > 0);

    DiffFile {
        old_path,
        new_path,
        status,
        hunks,
        is_binary,
        is_too_large,
        is_commit_message: false,
    }
}

// --- ForgeBackend implementation ---
//
// Split into one `impl` block per capability trait (Phase H5). The
// supertrait alias `ForgeBackend` is auto-derived via the blanket impl in
// `travelagent_core::forge`.

#[async_trait]
impl ForgeRead for GitHubForge {
    fn forge_type(&self) -> ForgeType {
        ForgeType::GitHub
    }

    async fn get_pr(&self, id: &PrId) -> Result<PrMetadata> {
        let path = format!("/repos/{}/{}/pulls/{}", id.owner, id.repo, id.number);
        let gh: GhPullRequest = self.get(&path).await?;
        convert_pr(gh)
    }

    async fn get_pr_commits(&self, id: &PrId) -> Result<Vec<CommitInfo>> {
        let path = format!(
            "/repos/{}/{}/pulls/{}/commits",
            id.owner, id.repo, id.number
        );
        let gh: Vec<GhCommit> = self.get_all_pages(&path).await?;
        gh.into_iter().map(convert_commit).collect()
    }

    async fn list_prs(
        &self,
        owner: &str,
        repo: &str,
        filter: &PrListFilter,
    ) -> Result<Vec<PrListItem>> {
        let limit = cap_list_prs_max(filter.max.unwrap_or(default_list_prs_max())) as usize;

        // Map our PrState into GitHub's `state` query param.
        let state_param = match filter.state {
            Some(PrState::Closed) => "closed",
            Some(PrState::Merged) => "closed", // GitHub lumps merged into closed
            _ => "open",
        };
        let path =
            format!("/repos/{owner}/{repo}/pulls?state={state_param}&sort=updated&direction=desc");

        let rows: Vec<GhPullRequestListItem> = self.get_pages_up_to(&path, limit).await?;

        // Look up current user once so we can flag review-requested rows. Fail soft
        // — if the /user call errors, we just leave the flag as false rather than
        // failing the whole list fetch. A valid token may lack `user:read` but
        // still be able to read a repo's PRs.
        let me = self.current_user().await.ok().map(|u| u.login);

        let mut out: Vec<PrListItem> = rows
            .into_iter()
            .map(|row| convert_pr_list_item(row, me.as_deref()))
            .collect::<Result<_>>()?;

        // Client-side filters. GitHub's list endpoint has no server-side
        // assignee filter, but PR #138 wired `assignees` into `PrListItem`,
        // so we can honour `filter.assignee` here without a richer path.
        // Comparisons are case-insensitive to match the TUI picker and
        // tolerate GitHub's mixed-case login echoes.
        if let Some(ref who) = filter.author {
            out.retain(|r| r.author.eq_ignore_ascii_case(who));
        }
        if let Some(ref who) = filter.assignee {
            out.retain(|r| r.assignees.iter().any(|a| a.eq_ignore_ascii_case(who)));
        }
        if let Some(true) = filter.review_requested {
            out.retain(|r| r.has_review_requested_from_me);
        }

        Ok(out)
    }

    async fn get_pr_files(&self, id: &PrId) -> Result<Vec<DiffFile>> {
        let path = format!("/repos/{}/{}/pulls/{}/files", id.owner, id.repo, id.number);
        let gh: Vec<GhFile> = self.get_all_pages(&path).await?;
        Ok(parse_gh_files(gh))
    }

    async fn get_commit_diff(&self, id: &PrId, commit_sha: &str) -> Result<Vec<DiffFile>> {
        if !commit_sha.chars().all(|c| c.is_ascii_hexdigit()) {
            return Err(TrvError::ForgeApi(format!(
                "Invalid commit SHA: '{commit_sha}'"
            )));
        }
        let path = format!("/repos/{}/{}/commits/{}", id.owner, id.repo, commit_sha);
        let gh: GhCommitDetail2 = self.get(&path).await?;
        Ok(parse_gh_files(gh.files.unwrap_or_default()))
    }

    async fn current_user(&self) -> Result<User> {
        let gh: GhUser = self.get("/user").await?;
        Ok(User {
            login: gh.login,
            id: gh.id,
        })
    }

    async fn check_permissions(&self, id: &PrId) -> Result<Permissions> {
        let path = format!("/repos/{}/{}", id.owner, id.repo);
        let gh: GhRepo = self.get(&path).await?;

        let perms = gh.permissions.unwrap_or(GhRepoPermissions {
            push: None,
            maintain: None,
            admin: None,
        });

        let can_push = perms.push.unwrap_or(false)
            || perms.maintain.unwrap_or(false)
            || perms.admin.unwrap_or(false);
        let can_merge = perms.maintain.unwrap_or(false) || perms.admin.unwrap_or(false);

        let mut allowed_merge_methods = Vec::new();
        if gh.allow_merge_commit.unwrap_or(true) {
            allowed_merge_methods.push(MergeMethod::Merge);
        }
        if gh.allow_squash_merge.unwrap_or(true) {
            allowed_merge_methods.push(MergeMethod::Squash);
        }
        if gh.allow_rebase_merge.unwrap_or(true) {
            allowed_merge_methods.push(MergeMethod::Rebase);
        }

        Ok(Permissions {
            can_push,
            can_merge,
            allowed_merge_methods,
        })
    }
}

#[async_trait]
impl ForgeComments for GitHubForge {
    async fn get_comments(&self, id: &PrId) -> Result<Vec<RemoteComment>> {
        // Fetch inline review comments
        let review_path = format!(
            "/repos/{}/{}/pulls/{}/comments",
            id.owner, id.repo, id.number
        );
        let review_comments: Vec<GhReviewComment> = self.get_all_pages(&review_path).await?;

        // Fetch general issue comments
        let issue_path = format!(
            "/repos/{}/{}/issues/{}/comments",
            id.owner, id.repo, id.number
        );
        let issue_comments: Vec<GhIssueComment> = self.get_all_pages(&issue_path).await?;

        let mut all: Vec<RemoteComment> = review_comments
            .into_iter()
            .map(convert_review_comment)
            .collect::<Result<Vec<_>>>()?;

        for ic in issue_comments {
            all.push(RemoteComment {
                id: ic.id,
                author: ic.user.login,
                body: ic.body.unwrap_or_default(),
                path: None,
                line: None,
                side: None,
                created_at: parse_datetime(&ic.created_at)?,
                in_reply_to: None,
            });
        }

        all.sort_by_key(|c| c.created_at);
        Ok(all)
    }

    async fn get_review_threads(&self, id: &PrId) -> Result<Vec<ReviewThread>> {
        const MAX_PAGES: usize = 50;
        let mut all_threads = Vec::new();
        let mut cursor: Option<String> = None;

        let query = r"query($owner: String!, $name: String!, $number: Int!, $after: String) {
  repository(owner: $owner, name: $name) {
    pullRequest(number: $number) {
      reviewThreads(first: 100, after: $after) {
        pageInfo { hasNextPage endCursor }
        nodes {
          id
          isResolved
          comments(first: 1) {
            nodes { databaseId }
          }
        }
      }
    }
  }
}";

        for _ in 0..MAX_PAGES {
            let variables = serde_json::json!({
                "owner": id.owner,
                "name": id.repo,
                "number": id.number,
                "after": cursor,
            });

            let body = self.graphql_with_vars(query, variables).await?;

            let review_threads = body
                .pointer("/data/repository/pullRequest/reviewThreads")
                .cloned()
                .unwrap_or_default();

            let nodes = review_threads
                .get("nodes")
                .and_then(|v| v.as_array())
                .cloned()
                .unwrap_or_default();

            for t in nodes {
                let thread_id = t
                    .get("id")
                    .and_then(|v| v.as_str())
                    .unwrap_or_default()
                    .to_string();
                let is_resolved = t
                    .get("isResolved")
                    .and_then(serde_json::Value::as_bool)
                    .unwrap_or(false);
                let root_comment_id = t
                    .pointer("/comments/nodes/0/databaseId")
                    .and_then(serde_json::Value::as_u64)
                    .unwrap_or(0);

                all_threads.push(ReviewThread {
                    id: thread_id,
                    is_resolved,
                    root_comment_id,
                });
            }

            let has_next = review_threads
                .pointer("/pageInfo/hasNextPage")
                .and_then(serde_json::Value::as_bool)
                .unwrap_or(false);

            if has_next {
                cursor = review_threads
                    .pointer("/pageInfo/endCursor")
                    .and_then(|v| v.as_str())
                    .map(std::string::ToString::to_string);
            } else {
                break;
            }
        }

        Ok(all_threads)
    }

    async fn post_comment(&self, id: &PrId, comment: NewComment) -> Result<RemoteComment> {
        let commit_id = if let Some(sha) = &comment.commit_id {
            sha.clone()
        } else {
            let pr_path = format!("/repos/{}/{}/pulls/{}", id.owner, id.repo, id.number);
            let pr: GhPullRequest = self.get(&pr_path).await?;
            pr.head.sha
        };
        let path = format!(
            "/repos/{}/{}/pulls/{}/comments",
            id.owner, id.repo, id.number
        );
        let side = match comment.side {
            LineSide::Old => "LEFT",
            LineSide::New => "RIGHT",
        };
        let mut body = serde_json::json!({
            "path": comment.path,
            "body": comment.body,
            "line": comment.line,
            "side": side,
            "commit_id": commit_id,
        });
        if let Some(start) = comment.start_line {
            let start_side = match comment.side {
                LineSide::Old => "LEFT",
                LineSide::New => "RIGHT",
            };
            body["start_line"] = serde_json::json!(start);
            body["start_side"] = serde_json::json!(start_side);
        }
        let gh: GhReviewComment = self.post(&path, &body).await?;
        convert_review_comment(gh)
    }

    async fn post_reply(&self, id: &PrId, thread_id: &str, body: &str) -> Result<RemoteComment> {
        // thread_id should be the root comment's numeric database ID
        let comment_id: u64 = thread_id.parse().map_err(|_| {
            TrvError::ForgeApi(format!(
                "Invalid comment ID for reply: '{thread_id}'. \
                 Pass the root comment's numeric ID, not the GraphQL thread node ID."
            ))
        })?;
        let path = format!(
            "/repos/{}/{}/pulls/{}/comments",
            id.owner, id.repo, id.number
        );
        let req_body = serde_json::json!({
            "body": body,
            "in_reply_to": comment_id,
        });
        let gh: GhReviewComment = self.post(&path, &req_body).await?;
        convert_review_comment(gh)
    }

    async fn edit_comment(&self, id: &PrId, comment_id: u64, body: &str) -> Result<RemoteComment> {
        let path = format!(
            "/repos/{}/{}/pulls/comments/{}",
            id.owner, id.repo, comment_id
        );
        let req_body = serde_json::json!({ "body": body });
        let gh: GhReviewComment = self.patch(&path, &req_body).await?;
        convert_review_comment(gh)
    }

    async fn delete_comment(&self, id: &PrId, comment_id: u64) -> Result<()> {
        let path = format!(
            "/repos/{}/{}/pulls/comments/{}",
            id.owner, id.repo, comment_id
        );
        self.delete(&path).await
    }

    async fn resolve_thread(&self, thread_id: &str) -> Result<()> {
        let query = r"mutation($threadId: ID!) {
  resolveReviewThread(input: { threadId: $threadId }) {
    thread { id isResolved }
  }
}";
        let variables = serde_json::json!({ "threadId": thread_id });
        self.graphql_with_vars(query, variables).await?;
        Ok(())
    }

    async fn unresolve_thread(&self, thread_id: &str) -> Result<()> {
        let query = r"mutation($threadId: ID!) {
  unresolveReviewThread(input: { threadId: $threadId }) {
    thread { id isResolved }
  }
}";
        let variables = serde_json::json!({ "threadId": thread_id });
        self.graphql_with_vars(query, variables).await?;
        Ok(())
    }
}

#[async_trait]
impl ForgeReview for GitHubForge {
    async fn submit_review(&self, id: &PrId, review: NewReview) -> Result<()> {
        let path = format!(
            "/repos/{}/{}/pulls/{}/reviews",
            id.owner, id.repo, id.number
        );
        let event = match review.verdict {
            ReviewVerdict::Approve => "APPROVE",
            ReviewVerdict::RequestChanges => "REQUEST_CHANGES",
            ReviewVerdict::Comment => "COMMENT",
        };
        let comments: Vec<serde_json::Value> = review
            .comments
            .into_iter()
            .map(|c| {
                let side = match c.side {
                    LineSide::Old => "LEFT",
                    LineSide::New => "RIGHT",
                };
                let mut obj = serde_json::json!({
                    "path": c.path,
                    "body": c.body,
                    "line": c.line,
                    "side": side,
                });
                if let Some(start) = c.start_line {
                    obj["start_line"] = serde_json::json!(start);
                    obj["start_side"] = serde_json::json!(side);
                }
                obj
            })
            .collect();

        let body = serde_json::json!({
            "body": review.body,
            "event": event,
            "comments": comments,
        });
        self.post_no_content(&path, &body).await
    }
}

#[async_trait]
impl ForgeMerge for GitHubForge {
    async fn merge(&self, id: &PrId, method: MergeMethod) -> Result<()> {
        let path = format!("/repos/{}/{}/pulls/{}/merge", id.owner, id.repo, id.number);
        let merge_method = match method {
            MergeMethod::Merge => "merge",
            MergeMethod::Squash => "squash",
            MergeMethod::Rebase => "rebase",
        };
        let body = serde_json::json!({ "merge_method": merge_method });
        self.put_no_content(&path, &body).await
    }

    async fn close(&self, id: &PrId) -> Result<()> {
        let path = format!("/repos/{}/{}/pulls/{}", id.owner, id.repo, id.number);
        let body = serde_json::json!({ "state": "closed" });
        let _: serde_json::Value = self.patch(&path, &body).await?;
        Ok(())
    }

    async fn reopen(&self, id: &PrId) -> Result<()> {
        let path = format!("/repos/{}/{}/pulls/{}", id.owner, id.repo, id.number);
        let body = serde_json::json!({ "state": "open" });
        let _: serde_json::Value = self.patch(&path, &body).await?;
        Ok(())
    }
}

#[async_trait]
impl ForgeReactions for GitHubForge {
    async fn add_reaction(&self, target: &ReactionTarget, content: ReactionContent) -> Result<()> {
        match target {
            ReactionTarget::IssueComment(_) => {
                Err(TrvError::UnsupportedOperation(
                    "add_reaction for IssueComment requires repository context not available in current trait".into(),
                ))
            }
            ReactionTarget::ReviewComment(_) => {
                Err(TrvError::UnsupportedOperation(
                    "add_reaction for ReviewComment requires repository context not available in current trait".into(),
                ))
            }
            ReactionTarget::Review(node_id) => {
                let query = r"mutation($subjectId: ID!, $content: ReactionContent!) {
  addReaction(input: { subjectId: $subjectId, content: $content }) {
    reaction { content }
  }
}";
                let variables = serde_json::json!({
                    "subjectId": node_id,
                    "content": reaction_to_graphql(content),
                });
                self.graphql_with_vars(query, variables).await?;
                Ok(())
            }
        }
    }

    async fn remove_reaction(
        &self,
        target: &ReactionTarget,
        content: ReactionContent,
    ) -> Result<()> {
        match target {
            ReactionTarget::IssueComment(_) | ReactionTarget::ReviewComment(_) => {
                Err(TrvError::UnsupportedOperation(
                    "remove_reaction requires repository context not available in current trait"
                        .into(),
                ))
            }
            ReactionTarget::Review(node_id) => {
                let query = r"mutation($subjectId: ID!, $content: ReactionContent!) {
  removeReaction(input: { subjectId: $subjectId, content: $content }) {
    reaction { content }
  }
}";
                let variables = serde_json::json!({
                    "subjectId": node_id,
                    "content": reaction_to_graphql(content),
                });
                self.graphql_with_vars(query, variables).await?;
                Ok(())
            }
        }
    }
}

fn reaction_to_graphql(content: ReactionContent) -> &'static str {
    match content {
        ReactionContent::ThumbsUp => "THUMBS_UP",
        ReactionContent::ThumbsDown => "THUMBS_DOWN",
        ReactionContent::Laugh => "LAUGH",
        ReactionContent::Hooray => "HOORAY",
        ReactionContent::Confused => "CONFUSED",
        ReactionContent::Heart => "HEART",
        ReactionContent::Rocket => "ROCKET",
        ReactionContent::Eyes => "EYES",
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::types::{GhCommitDetail, GhGitActor, GhRef};

    #[test]
    fn parse_next_link_with_next() {
        let header = r#"<https://api.github.com/repos/o/r/pulls?page=2>; rel="next", <https://api.github.com/repos/o/r/pulls?page=5>; rel="last""#;
        assert_eq!(
            parse_next_link(header),
            Some("https://api.github.com/repos/o/r/pulls?page=2".to_string())
        );
    }

    #[test]
    fn parse_next_link_without_next() {
        let header = r#"<https://api.github.com/repos/o/r/pulls?page=5>; rel="last""#;
        assert_eq!(parse_next_link(header), None);
    }

    #[test]
    fn parse_next_link_empty() {
        assert_eq!(parse_next_link(""), None);
    }

    #[test]
    fn parse_hunk_header_basic() {
        use travelagent_core::vcs::diff_parser::parse_hunk_header;
        assert_eq!(parse_hunk_header("@@ -1,3 +1,4 @@"), Some((1, 3, 1, 4)));
    }

    #[test]
    fn parse_hunk_header_with_context() {
        use travelagent_core::vcs::diff_parser::parse_hunk_header;
        assert_eq!(
            parse_hunk_header("@@ -10,5 +20,8 @@ fn main()"),
            Some((10, 5, 20, 8))
        );
    }

    #[test]
    fn parse_hunk_header_no_count() {
        use travelagent_core::vcs::diff_parser::parse_hunk_header;
        assert_eq!(parse_hunk_header("@@ -5 +10 @@"), Some((5, 1, 10, 1)));
    }

    #[test]
    fn parse_patch_single_hunk() {
        use travelagent_core::model::LineOrigin;
        let patch = "@@ -1,3 +1,4 @@\n line1\n+added\n line2\n line3";
        let hunks = parse_patch_hunks(patch);
        assert_eq!(hunks.len(), 1);
        assert_eq!(hunks[0].lines.len(), 4);
        assert_eq!(hunks[0].lines[0].origin, LineOrigin::Context);
        assert_eq!(hunks[0].lines[1].origin, LineOrigin::Addition);
        assert_eq!(hunks[0].lines[1].content, "added");
    }

    #[test]
    fn parse_patch_multiple_hunks() {
        let patch = "@@ -1,2 +1,3 @@\n a\n+b\n c\n@@ -10,1 +11,1 @@\n-old\n+new";
        let hunks = parse_patch_hunks(patch);
        assert_eq!(hunks.len(), 2);
    }

    #[test]
    fn parse_patch_line_numbers() {
        let patch = "@@ -5,3 +5,4 @@\n ctx\n-del\n+add1\n+add2";
        let hunks = parse_patch_hunks(patch);
        let lines = &hunks[0].lines;

        assert_eq!(lines[0].old_lineno, Some(5));
        assert_eq!(lines[0].new_lineno, Some(5));
        assert_eq!(lines[1].old_lineno, Some(6));
        assert_eq!(lines[1].new_lineno, None);
        assert_eq!(lines[2].old_lineno, None);
        assert_eq!(lines[2].new_lineno, Some(6));
        assert_eq!(lines[3].old_lineno, None);
        assert_eq!(lines[3].new_lineno, Some(7));
    }

    #[test]
    fn parse_single_gh_file_added() {
        let gh = GhFile {
            filename: "new.rs".into(),
            status: "added".into(),
            additions: 5,
            deletions: 0,
            patch: Some("@@ -0,0 +1,2 @@\n+line1\n+line2".into()),
            previous_filename: None,
        };
        let df = parse_single_gh_file(gh);
        assert_eq!(df.status, FileStatus::Added);
        assert!(df.old_path.is_none());
        assert_eq!(df.new_path, Some(std::path::PathBuf::from("new.rs")));
        assert_eq!(df.hunks.len(), 1);
    }

    #[test]
    fn parse_single_gh_file_renamed() {
        let gh = GhFile {
            filename: "new_name.rs".into(),
            status: "renamed".into(),
            additions: 0,
            deletions: 0,
            patch: None,
            previous_filename: Some("old_name.rs".into()),
        };
        let df = parse_single_gh_file(gh);
        assert_eq!(df.status, FileStatus::Renamed);
        assert_eq!(df.old_path, Some(std::path::PathBuf::from("old_name.rs")));
        assert_eq!(df.new_path, Some(std::path::PathBuf::from("new_name.rs")));
        assert!(!df.is_binary);
    }

    #[test]
    fn parse_single_gh_file_binary() {
        let gh = GhFile {
            filename: "image.png".into(),
            status: "modified".into(),
            additions: 0,
            deletions: 0,
            patch: None,
            previous_filename: None,
        };
        let df = parse_single_gh_file(gh);
        assert!(df.is_binary);
    }

    #[test]
    fn convert_pr_open() {
        let gh = GhPullRequest {
            number: 1,
            title: "test".into(),
            body: Some("body".into()),
            state: "open".into(),
            draft: Some(false),
            merged_at: None,
            user: GhUser {
                login: "alice".into(),
                id: 1,
            },
            base: GhRef {
                ref_name: "main".into(),
                sha: "abc".into(),
            },
            head: GhRef {
                ref_name: "feat".into(),
                sha: "def".into(),
            },
            created_at: "2024-01-01T00:00:00Z".into(),
            mergeable_state: Some("clean".into()),
            mergeable: Some(true),
        };
        let pr = convert_pr(gh).unwrap();
        assert_eq!(pr.state, PrState::Open);
        assert_eq!(pr.mergeable, Some(MergeableStatus::Clean));
        assert!(!pr.is_draft);
    }

    #[test]
    fn convert_pr_merged() {
        let gh = GhPullRequest {
            number: 2,
            title: "merged".into(),
            body: None,
            state: "closed".into(),
            draft: None,
            merged_at: Some("2024-01-02T00:00:00Z".into()),
            user: GhUser {
                login: "bob".into(),
                id: 2,
            },
            base: GhRef {
                ref_name: "main".into(),
                sha: "abc".into(),
            },
            head: GhRef {
                ref_name: "fix".into(),
                sha: "def".into(),
            },
            created_at: "2024-01-01T00:00:00Z".into(),
            mergeable_state: None,
            mergeable: None,
        };
        let pr = convert_pr(gh).unwrap();
        assert_eq!(pr.state, PrState::Merged);
        assert_eq!(pr.body, "");
    }

    #[test]
    fn convert_pr_list_item_open_pr_no_reviewers() {
        let gh = GhPullRequestListItem {
            number: 1,
            title: "feat: stuff".into(),
            state: "open".into(),
            draft: Some(false),
            merged_at: None,
            user: GhUser {
                login: "alice".into(),
                id: 1,
            },
            base: GhRef {
                ref_name: "main".into(),
                sha: "abc".into(),
            },
            head: GhRef {
                ref_name: "feat".into(),
                sha: "def".into(),
            },
            updated_at: "2024-06-15T10:30:00Z".into(),
            requested_reviewers: vec![],
            assignees: vec![],
            comments: Some(2),
            review_comments: Some(3),
        };
        let item = convert_pr_list_item(gh, Some("bob")).unwrap();
        assert_eq!(item.number, 1);
        assert_eq!(item.state, PrState::Open);
        assert_eq!(item.author, "alice");
        assert_eq!(item.comment_count, 5);
        assert!(!item.is_draft);
        assert!(!item.has_review_requested_from_me);
    }

    #[test]
    fn convert_pr_list_item_merged_state_detected_via_merged_at() {
        let gh = GhPullRequestListItem {
            number: 2,
            title: "chore".into(),
            state: "closed".into(),
            draft: None,
            merged_at: Some("2024-06-16T12:00:00Z".into()),
            user: GhUser {
                login: "bob".into(),
                id: 2,
            },
            base: GhRef {
                ref_name: "main".into(),
                sha: "a".into(),
            },
            head: GhRef {
                ref_name: "f".into(),
                sha: "b".into(),
            },
            updated_at: "2024-06-16T12:00:00Z".into(),
            requested_reviewers: vec![],
            assignees: vec![],
            comments: None,
            review_comments: None,
        };
        let item = convert_pr_list_item(gh, None).unwrap();
        assert_eq!(item.state, PrState::Merged);
        assert_eq!(item.comment_count, 0);
    }

    #[test]
    fn convert_pr_list_item_flags_review_requested_for_current_user() {
        let gh = GhPullRequestListItem {
            number: 3,
            title: "fix".into(),
            state: "open".into(),
            draft: Some(true),
            merged_at: None,
            user: GhUser {
                login: "alice".into(),
                id: 1,
            },
            base: GhRef {
                ref_name: "main".into(),
                sha: "a".into(),
            },
            head: GhRef {
                ref_name: "f".into(),
                sha: "b".into(),
            },
            updated_at: "2024-06-15T10:30:00Z".into(),
            requested_reviewers: vec![
                GhUser {
                    login: "carol".into(),
                    id: 3,
                },
                GhUser {
                    login: "bob".into(),
                    id: 2,
                },
            ],
            assignees: vec![],
            comments: Some(0),
            review_comments: Some(0),
        };
        let item = convert_pr_list_item(gh, Some("bob")).unwrap();
        assert!(item.is_draft);
        assert!(item.has_review_requested_from_me);
        assert_eq!(item.reviewers, vec!["carol".to_string(), "bob".to_string()]);
    }

    #[test]
    fn cap_list_prs_max_clamps_to_one_and_hundred() {
        assert_eq!(cap_list_prs_max(0), 1);
        assert_eq!(cap_list_prs_max(30), 30);
        assert_eq!(cap_list_prs_max(1000), 100);
    }

    #[test]
    fn convert_commit_basic() {
        let gh = GhCommit {
            sha: "abc123def456".into(),
            commit: GhCommitDetail {
                message: "Fix bug\n\nDetailed description".into(),
                author: GhGitActor {
                    name: "Alice".into(),
                    date: Some("2024-01-01T00:00:00Z".into()),
                },
            },
            author: Some(GhUser {
                login: "alice".into(),
                id: 1,
            }),
        };
        let ci = convert_commit(gh).unwrap();
        assert_eq!(ci.id, "abc123def456");
        assert_eq!(ci.short_id, "abc123d");
        assert_eq!(ci.summary, "Fix bug");
        assert_eq!(ci.body, Some("Detailed description".into()));
        assert_eq!(ci.author, "alice");
    }

    #[test]
    fn graphql_url_github_com() {
        let forge = GitHubForge {
            client: Client::new(),
            base_url: "https://api.github.com".into(),
            warn_handler: None,
        };
        assert_eq!(forge.graphql_url(), "https://api.github.com/graphql");
    }

    #[test]
    fn graphql_url_ghe() {
        let forge = GitHubForge {
            client: Client::new(),
            base_url: "https://github.example.com/api/v3".into(),
            warn_handler: None,
        };
        assert_eq!(
            forge.graphql_url(),
            "https://github.example.com/api/graphql"
        );
    }

    // --- SSRF / base_url validation ---

    #[test]
    fn validate_base_url_accepts_https_domain() {
        let got = GitHubForge::validate_base_url("https://api.github.com", false).unwrap();
        assert_eq!(got, "https://api.github.com");
    }

    #[test]
    fn validate_base_url_accepts_ghe_with_trailing_slash() {
        let got =
            GitHubForge::validate_base_url("https://github.example.com/api/v3/", false).unwrap();
        assert_eq!(got, "https://github.example.com/api/v3");
    }

    #[test]
    fn validate_base_url_rejects_http_scheme() {
        let err = GitHubForge::validate_base_url("http://api.github.com", false).unwrap_err();
        assert!(matches!(err, TrvError::AuthError(_)));
    }

    #[test]
    fn validate_base_url_rejects_non_url() {
        let err = GitHubForge::validate_base_url("not a url", false).unwrap_err();
        assert!(matches!(err, TrvError::AuthError(_)));
    }

    #[test]
    fn validate_base_url_rejects_loopback_v4() {
        let err = GitHubForge::validate_base_url("https://127.0.0.1", false).unwrap_err();
        assert!(matches!(err, TrvError::AuthError(_)));
    }

    #[test]
    fn validate_base_url_rejects_private_v4() {
        for url in [
            "https://10.0.0.1",
            "https://192.168.1.1",
            "https://172.16.0.1",
        ] {
            let err = GitHubForge::validate_base_url(url, false).unwrap_err();
            assert!(
                matches!(err, TrvError::AuthError(_)),
                "expected AuthError for {url}"
            );
        }
    }

    #[test]
    fn validate_base_url_rejects_link_local_v4() {
        let err = GitHubForge::validate_base_url("https://169.254.169.254", false).unwrap_err();
        assert!(matches!(err, TrvError::AuthError(_)));
    }

    #[test]
    fn validate_base_url_rejects_unspecified_v4() {
        let err = GitHubForge::validate_base_url("https://0.0.0.0", false).unwrap_err();
        assert!(matches!(err, TrvError::AuthError(_)));
    }

    #[test]
    fn validate_base_url_rejects_loopback_v6() {
        let err = GitHubForge::validate_base_url("https://[::1]", false).unwrap_err();
        assert!(matches!(err, TrvError::AuthError(_)));
    }

    #[test]
    fn validate_base_url_rejects_link_local_v6() {
        let err = GitHubForge::validate_base_url("https://[fe80::1]", false).unwrap_err();
        assert!(matches!(err, TrvError::AuthError(_)));
    }

    #[test]
    fn validate_base_url_allows_loopback_when_insecure() {
        let got = GitHubForge::validate_base_url("http://127.0.0.1:8080", true).unwrap();
        assert_eq!(got, "http://127.0.0.1:8080");
    }

    #[test]
    fn with_token_insecure_allows_loopback_http() {
        let forge = GitHubForge::with_token_insecure("http://127.0.0.1:1234", "tok".into());
        assert!(forge.is_ok());
    }

    #[test]
    fn is_blocked_ip_covers_cgnat() {
        let ip: IpAddr = "100.64.0.1".parse().unwrap();
        assert!(is_blocked_ip(&ip));
        let ip: IpAddr = "100.127.255.255".parse().unwrap();
        assert!(is_blocked_ip(&ip));
        // Just outside CGNAT
        let ip: IpAddr = "100.128.0.1".parse().unwrap();
        assert!(!is_blocked_ip(&ip));
    }

    // --- HTTP client builder timeouts ---

    #[test]
    fn with_token_builds_client_with_timeouts() {
        // The reqwest::Client API doesn't expose timeouts for read-back, so we
        // exercise the code path and assert the builder succeeds with them set.
        let forge = GitHubForge::with_token("https://api.github.com", "tok".into());
        assert!(forge.is_ok());
    }

    // --- Invalid token error message ---

    #[test]
    fn with_token_invalid_bytes_returns_static_message() {
        // \n is not allowed in HTTP header values; the builder must reject it
        // without echoing the underlying cause (which may contain the token).
        let bad_token = "abc\ndef".to_string();
        let result = GitHubForge::with_token("https://api.github.com", bad_token);
        let err = match result {
            Err(e) => e,
            Ok(_) => panic!("expected with_token to fail for invalid header bytes"),
        };
        match err {
            TrvError::AuthError(msg) => {
                assert_eq!(
                    msg,
                    "token contains invalid header bytes; check GITHUB_TOKEN"
                );
                assert!(!msg.contains("abc"));
                assert!(!msg.contains("def"));
            }
            other => panic!("expected AuthError, got {other:?}"),
        }
    }

    // --- Error body sanitizer ---

    #[test]
    fn sanitize_error_body_strips_authorization_line() {
        let body = "Something went wrong\nAuthorization: Bearer abc123\nmore text";
        let got = sanitize_error_body(body);
        assert!(!got.to_ascii_lowercase().contains("authorization"));
        assert!(!got.contains("abc123"));
        assert!(got.contains("Something went wrong"));
        assert!(got.contains("more text"));
    }

    #[test]
    fn sanitize_error_body_strips_private_token_case_insensitive() {
        let body = "prefix\nprivate-token: glpat-abc\nPRIVATE-TOKEN: other\nsuffix";
        let got = sanitize_error_body(body);
        assert!(!got.contains("glpat-abc"));
        assert!(!got.contains("other"));
        assert!(got.contains("prefix"));
        assert!(got.contains("suffix"));
    }

    #[test]
    fn sanitize_error_body_strips_x_token_headers() {
        let body = "line1\nx-github-token: ghp_secret\nx-gitlab-token: tok2\nline2";
        let got = sanitize_error_body(body);
        assert!(!got.contains("ghp_secret"));
        assert!(!got.contains("tok2"));
        assert!(got.contains("line1"));
        assert!(got.contains("line2"));
    }

    #[test]
    fn sanitize_error_body_truncates_large_payload() {
        let body = "a".repeat(10_000);
        let got = sanitize_error_body(&body);
        assert!(got.len() <= MAX_ERROR_BODY_BYTES + "... [truncated]".len());
        assert!(got.ends_with("... [truncated]"));
    }

    #[test]
    fn sanitize_error_body_preserves_short_body() {
        let body = "{\"message\":\"Not Found\"}";
        let got = sanitize_error_body(body);
        assert_eq!(got, body);
    }

    #[test]
    fn line_looks_like_credential_header_cases() {
        assert!(line_looks_like_credential_header(
            "Authorization: Bearer abc"
        ));
        assert!(line_looks_like_credential_header("authorization:x"));
        assert!(line_looks_like_credential_header("Private-Token: abc"));
        assert!(line_looks_like_credential_header("X-GitHub-Token: abc"));
        assert!(line_looks_like_credential_header("x-token: abc"));
        // Not a credential header:
        assert!(!line_looks_like_credential_header("Content-Type: json"));
        assert!(!line_looks_like_credential_header("message: bad request"));
        assert!(!line_looks_like_credential_header("no colon here"));
        assert!(!line_looks_like_credential_header("X-Request-Id: abc"));
    }

    // --- Warn handler routing ---

    #[test]
    fn emit_warning_routes_through_handler_when_installed() {
        use std::sync::{Arc, Mutex};
        let captured: Arc<Mutex<Vec<String>>> = Arc::new(Mutex::new(Vec::new()));
        let sink = Arc::clone(&captured);
        let forge = GitHubForge::with_token("https://api.github.com", "tok".into())
            .unwrap()
            .with_warn_handler(Arc::new(move |msg| {
                sink.lock().unwrap().push(msg);
            }));
        forge.emit_warning("hello".to_string());
        let got = captured.lock().unwrap().clone();
        assert_eq!(got, vec!["hello".to_string()]);
    }

    #[test]
    fn emit_warning_falls_back_without_handler() {
        // Without a handler installed, emit_warning routes to stderr via
        // eprintln!. We can't capture stderr here, but exercising the code
        // path guarantees it doesn't panic / deadlock.
        let forge = GitHubForge::with_token("https://api.github.com", "tok".into()).unwrap();
        assert!(forge.warn_handler.is_none());
        forge.emit_warning("fallback".to_string());
    }
}