//! Show command - display detailed entity information from local database.

use console::style;
use rusqlite::Connection;
use serde::Serialize;

use crate::Config;
use crate::core::db::create_connection;
use crate::core::error::{LoreError, Result};
use crate::core::paths::get_db_path;
use crate::core::project::resolve_project;
use crate::core::time::ms_to_iso;

/// Merge request metadata for display.
#[derive(Debug, Serialize)]
pub struct MrDetail {
    pub id: i64,
    pub iid: i64,
    pub title: String,
    pub description: Option<String>,
    pub state: String,
    pub draft: bool,
    pub author_username: String,
    pub source_branch: String,
    pub target_branch: String,
    pub created_at: i64,
    pub updated_at: i64,
    pub merged_at: Option<i64>,
    pub closed_at: Option<i64>,
    pub web_url: Option<String>,
    pub project_path: String,
    pub labels: Vec<String>,
    pub assignees: Vec<String>,
    pub reviewers: Vec<String>,
    pub discussions: Vec<MrDiscussionDetail>,
}

/// MR discussion detail for display.
#[derive(Debug, Serialize)]
pub struct MrDiscussionDetail {
    pub notes: Vec<MrNoteDetail>,
    pub individual_note: bool,
}

/// MR note detail for display (includes DiffNote position).
#[derive(Debug, Serialize)]
pub struct MrNoteDetail {
    pub author_username: String,
    pub body: String,
    pub created_at: i64,
    pub is_system: bool,
    pub position: Option<DiffNotePosition>,
}

/// DiffNote position context for display.
#[derive(Debug, Clone, Serialize)]
pub struct DiffNotePosition {
    pub old_path: Option<String>,
    pub new_path: Option<String>,
    pub old_line: Option<i64>,
    pub new_line: Option<i64>,
    pub position_type: Option<String>,
}

/// Issue metadata for display.
#[derive(Debug, Serialize)]
pub struct IssueDetail {
    pub id: i64,
    pub iid: i64,
    pub title: String,
    pub description: Option<String>,
    pub state: String,
    pub author_username: String,
    pub created_at: i64,
    pub updated_at: i64,
    pub web_url: Option<String>,
    pub project_path: String,
    pub labels: Vec<String>,
    pub discussions: Vec<DiscussionDetail>,
}

/// Discussion detail for display.
#[derive(Debug, Serialize)]
pub struct DiscussionDetail {
    pub notes: Vec<NoteDetail>,
    pub individual_note: bool,
}

/// Note detail for display.
#[derive(Debug, Serialize)]
pub struct NoteDetail {
    pub author_username: String,
    pub body: String,
    pub created_at: i64,
    pub is_system: bool,
}

/// Run the show issue command.
pub fn run_show_issue(
    config: &Config,
    iid: i64,
    project_filter: Option<&str>,
) -> Result<IssueDetail> {
    let db_path = get_db_path(config.storage.db_path.as_deref());
    let conn = create_connection(&db_path)?;

    // Find the issue
    let issue = find_issue(&conn, iid, project_filter)?;

    // Load labels
    let labels = get_issue_labels(&conn, issue.id)?;

    // Load discussions with notes
    let discussions = get_issue_discussions(&conn, issue.id)?;

    Ok(IssueDetail {
        id: issue.id,
        iid: issue.iid,
        title: issue.title,
        description: issue.description,
        state: issue.state,
        author_username: issue.author_username,
        created_at: issue.created_at,
        updated_at: issue.updated_at,
        web_url: issue.web_url,
        project_path: issue.project_path,
        labels,
        discussions,
    })
}

/// Internal issue row from query.
struct IssueRow {
    id: i64,
    iid: i64,
    title: String,
    description: Option<String>,
    state: String,
    author_username: String,
    created_at: i64,
    updated_at: i64,
    web_url: Option<String>,
    project_path: String,
}

/// Find issue by iid, optionally filtered by project.
fn find_issue(conn: &Connection, iid: i64, project_filter: Option<&str>) -> Result<IssueRow> {
    let (sql, params): (&str, Vec<Box<dyn rusqlite::ToSql>>) = match project_filter {
        Some(project) => {
            let project_id = resolve_project(conn, project)?;
            (
                "SELECT i.id, i.iid, i.title, i.description, i.state, i.author_username,
                        i.created_at, i.updated_at, i.web_url, p.path_with_namespace
                 FROM issues i
                 JOIN projects p ON i.project_id = p.id
                 WHERE i.iid = ? AND i.project_id = ?",
                vec![Box::new(iid), Box::new(project_id)],
            )
        }
        None => (
            "SELECT i.id, i.iid, i.title, i.description, i.state, i.author_username,
                    i.created_at, i.updated_at, i.web_url, p.path_with_namespace
             FROM issues i
             JOIN projects p ON i.project_id = p.id
             WHERE i.iid = ?",
            vec![Box::new(iid)],
        ),
    };

    let param_refs: Vec<&dyn rusqlite::ToSql> = params.iter().map(|p| p.as_ref()).collect();

    let mut stmt = conn.prepare(sql)?;
    let issues: Vec<IssueRow> = stmt
        .query_map(param_refs.as_slice(), |row| {
            Ok(IssueRow {
                id: row.get(0)?,
                iid: row.get(1)?,
                title: row.get(2)?,
                description: row.get(3)?,
                state: row.get(4)?,
                author_username: row.get(5)?,
                created_at: row.get(6)?,
                updated_at: row.get(7)?,
                web_url: row.get(8)?,
                project_path: row.get(9)?,
            })
        })?
        .collect::<std::result::Result<Vec<_>, _>>()?;

    match issues.len() {
        0 => Err(LoreError::NotFound(format!("Issue #{} not found", iid))),
        1 => Ok(issues.into_iter().next().unwrap()),
        _ => {
            let projects: Vec<String> = issues.iter().map(|i| i.project_path.clone()).collect();
            Err(LoreError::Ambiguous(format!(
                "Issue #{} exists in multiple projects: {}. Use --project to specify.",
                iid,
                projects.join(", ")
            )))
        }
    }
}

/// Get labels for an issue.
fn get_issue_labels(conn: &Connection, issue_id: i64) -> Result<Vec<String>> {
    let mut stmt = conn.prepare(
        "SELECT l.name FROM labels l
         JOIN issue_labels il ON l.id = il.label_id
         WHERE il.issue_id = ?
         ORDER BY l.name",
    )?;

    let labels: Vec<String> = stmt
        .query_map([issue_id], |row| row.get(0))?
        .collect::<std::result::Result<Vec<_>, _>>()?;

    Ok(labels)
}

/// Get discussions with notes for an issue.
fn get_issue_discussions(conn: &Connection, issue_id: i64) -> Result<Vec<DiscussionDetail>> {
    // First get all discussions
    let mut disc_stmt = conn.prepare(
        "SELECT id, individual_note FROM discussions
         WHERE issue_id = ?
         ORDER BY first_note_at",
    )?;

    let disc_rows: Vec<(i64, bool)> = disc_stmt
        .query_map([issue_id], |row| {
            let individual: i64 = row.get(1)?;
            Ok((row.get(0)?, individual == 1))
        })?
        .collect::<std::result::Result<Vec<_>, _>>()?;

    // Then get notes for each discussion
    let mut note_stmt = conn.prepare(
        "SELECT author_username, body, created_at, is_system
         FROM notes
         WHERE discussion_id = ?
         ORDER BY position",
    )?;

    let mut discussions = Vec::new();
    for (disc_id, individual_note) in disc_rows {
        let notes: Vec<NoteDetail> = note_stmt
            .query_map([disc_id], |row| {
                let is_system: i64 = row.get(3)?;
                Ok(NoteDetail {
                    author_username: row.get(0)?,
                    body: row.get(1)?,
                    created_at: row.get(2)?,
                    is_system: is_system == 1,
                })
            })?
            .collect::<std::result::Result<Vec<_>, _>>()?;

        // Filter out discussions with only system notes
        let has_user_notes = notes.iter().any(|n| !n.is_system);
        if has_user_notes || notes.is_empty() {
            discussions.push(DiscussionDetail {
                notes,
                individual_note,
            });
        }
    }

    Ok(discussions)
}

/// Run the show MR command.
pub fn run_show_mr(config: &Config, iid: i64, project_filter: Option<&str>) -> Result<MrDetail> {
    let db_path = get_db_path(config.storage.db_path.as_deref());
    let conn = create_connection(&db_path)?;

    // Find the MR
    let mr = find_mr(&conn, iid, project_filter)?;

    // Load labels
    let labels = get_mr_labels(&conn, mr.id)?;

    // Load assignees
    let assignees = get_mr_assignees(&conn, mr.id)?;

    // Load reviewers
    let reviewers = get_mr_reviewers(&conn, mr.id)?;

    // Load discussions with notes
    let discussions = get_mr_discussions(&conn, mr.id)?;

    Ok(MrDetail {
        id: mr.id,
        iid: mr.iid,
        title: mr.title,
        description: mr.description,
        state: mr.state,
        draft: mr.draft,
        author_username: mr.author_username,
        source_branch: mr.source_branch,
        target_branch: mr.target_branch,
        created_at: mr.created_at,
        updated_at: mr.updated_at,
        merged_at: mr.merged_at,
        closed_at: mr.closed_at,
        web_url: mr.web_url,
        project_path: mr.project_path,
        labels,
        assignees,
        reviewers,
        discussions,
    })
}

/// Internal MR row from query.
struct MrRow {
    id: i64,
    iid: i64,
    title: String,
    description: Option<String>,
    state: String,
    draft: bool,
    author_username: String,
    source_branch: String,
    target_branch: String,
    created_at: i64,
    updated_at: i64,
    merged_at: Option<i64>,
    closed_at: Option<i64>,
    web_url: Option<String>,
    project_path: String,
}

/// Find MR by iid, optionally filtered by project.
fn find_mr(conn: &Connection, iid: i64, project_filter: Option<&str>) -> Result<MrRow> {
    let (sql, params): (&str, Vec<Box<dyn rusqlite::ToSql>>) = match project_filter {
        Some(project) => {
            let project_id = resolve_project(conn, project)?;
            (
                "SELECT m.id, m.iid, m.title, m.description, m.state, m.draft,
                        m.author_username, m.source_branch, m.target_branch,
                        m.created_at, m.updated_at, m.merged_at, m.closed_at,
                        m.web_url, p.path_with_namespace
                 FROM merge_requests m
                 JOIN projects p ON m.project_id = p.id
                 WHERE m.iid = ? AND m.project_id = ?",
                vec![Box::new(iid), Box::new(project_id)],
            )
        }
        None => (
            "SELECT m.id, m.iid, m.title, m.description, m.state, m.draft,
                    m.author_username, m.source_branch, m.target_branch,
                    m.created_at, m.updated_at, m.merged_at, m.closed_at,
                    m.web_url, p.path_with_namespace
             FROM merge_requests m
             JOIN projects p ON m.project_id = p.id
             WHERE m.iid = ?",
            vec![Box::new(iid)],
        ),
    };

    let param_refs: Vec<&dyn rusqlite::ToSql> = params.iter().map(|p| p.as_ref()).collect();

    let mut stmt = conn.prepare(sql)?;
    let mrs: Vec<MrRow> = stmt
        .query_map(param_refs.as_slice(), |row| {
            let draft_val: i64 = row.get(5)?;
            Ok(MrRow {
                id: row.get(0)?,
                iid: row.get(1)?,
                title: row.get(2)?,
                description: row.get(3)?,
                state: row.get(4)?,
                draft: draft_val == 1,
                author_username: row.get(6)?,
                source_branch: row.get(7)?,
                target_branch: row.get(8)?,
                created_at: row.get(9)?,
                updated_at: row.get(10)?,
                merged_at: row.get(11)?,
                closed_at: row.get(12)?,
                web_url: row.get(13)?,
                project_path: row.get(14)?,
            })
        })?
        .collect::<std::result::Result<Vec<_>, _>>()?;

    match mrs.len() {
        0 => Err(LoreError::NotFound(format!("MR !{} not found", iid))),
        1 => Ok(mrs.into_iter().next().unwrap()),
        _ => {
            let projects: Vec<String> = mrs.iter().map(|m| m.project_path.clone()).collect();
            Err(LoreError::Ambiguous(format!(
                "MR !{} exists in multiple projects: {}. Use --project to specify.",
                iid,
                projects.join(", ")
            )))
        }
    }
}

/// Get labels for an MR.
fn get_mr_labels(conn: &Connection, mr_id: i64) -> Result<Vec<String>> {
    let mut stmt = conn.prepare(
        "SELECT l.name FROM labels l
         JOIN mr_labels ml ON l.id = ml.label_id
         WHERE ml.merge_request_id = ?
         ORDER BY l.name",
    )?;

    let labels: Vec<String> = stmt
        .query_map([mr_id], |row| row.get(0))?
        .collect::<std::result::Result<Vec<_>, _>>()?;

    Ok(labels)
}

/// Get assignees for an MR.
fn get_mr_assignees(conn: &Connection, mr_id: i64) -> Result<Vec<String>> {
    let mut stmt = conn.prepare(
        "SELECT username FROM mr_assignees
         WHERE merge_request_id = ?
         ORDER BY username",
    )?;

    let assignees: Vec<String> = stmt
        .query_map([mr_id], |row| row.get(0))?
        .collect::<std::result::Result<Vec<_>, _>>()?;

    Ok(assignees)
}

/// Get reviewers for an MR.
fn get_mr_reviewers(conn: &Connection, mr_id: i64) -> Result<Vec<String>> {
    let mut stmt = conn.prepare(
        "SELECT username FROM mr_reviewers
         WHERE merge_request_id = ?
         ORDER BY username",
    )?;

    let reviewers: Vec<String> = stmt
        .query_map([mr_id], |row| row.get(0))?
        .collect::<std::result::Result<Vec<_>, _>>()?;

    Ok(reviewers)
}

/// Get discussions with notes for an MR.
fn get_mr_discussions(conn: &Connection, mr_id: i64) -> Result<Vec<MrDiscussionDetail>> {
    // First get all discussions
    let mut disc_stmt = conn.prepare(
        "SELECT id, individual_note FROM discussions
         WHERE merge_request_id = ?
         ORDER BY first_note_at",
    )?;

    let disc_rows: Vec<(i64, bool)> = disc_stmt
        .query_map([mr_id], |row| {
            let individual: i64 = row.get(1)?;
            Ok((row.get(0)?, individual == 1))
        })?
        .collect::<std::result::Result<Vec<_>, _>>()?;

    // Then get notes for each discussion (with DiffNote position fields)
    let mut note_stmt = conn.prepare(
        "SELECT author_username, body, created_at, is_system,
                position_old_path, position_new_path, position_old_line,
                position_new_line, position_type
         FROM notes
         WHERE discussion_id = ?
         ORDER BY position",
    )?;

    let mut discussions = Vec::new();
    for (disc_id, individual_note) in disc_rows {
        let notes: Vec<MrNoteDetail> = note_stmt
            .query_map([disc_id], |row| {
                let is_system: i64 = row.get(3)?;
                let old_path: Option<String> = row.get(4)?;
                let new_path: Option<String> = row.get(5)?;
                let old_line: Option<i64> = row.get(6)?;
                let new_line: Option<i64> = row.get(7)?;
                let position_type: Option<String> = row.get(8)?;

                let position = if old_path.is_some()
                    || new_path.is_some()
                    || old_line.is_some()
                    || new_line.is_some()
                {
                    Some(DiffNotePosition {
                        old_path,
                        new_path,
                        old_line,
                        new_line,
                        position_type,
                    })
                } else {
                    None
                };

                Ok(MrNoteDetail {
                    author_username: row.get(0)?,
                    body: row.get(1)?,
                    created_at: row.get(2)?,
                    is_system: is_system == 1,
                    position,
                })
            })?
            .collect::<std::result::Result<Vec<_>, _>>()?;

        // Filter out discussions with only system notes
        let has_user_notes = notes.iter().any(|n| !n.is_system);
        if has_user_notes || notes.is_empty() {
            discussions.push(MrDiscussionDetail {
                notes,
                individual_note,
            });
        }
    }

    Ok(discussions)
}

/// Format date from ms epoch.
fn format_date(ms: i64) -> String {
    let iso = ms_to_iso(ms);
    // Extract just the date part (YYYY-MM-DD)
    iso.split('T').next().unwrap_or(&iso).to_string()
}

/// Truncate text with ellipsis (character-safe for UTF-8).
fn truncate(s: &str, max_len: usize) -> String {
    if s.chars().count() <= max_len {
        s.to_string()
    } else {
        let truncated: String = s.chars().take(max_len.saturating_sub(3)).collect();
        format!("{truncated}...")
    }
}

/// Wrap text to width, with indent prefix on continuation lines.
fn wrap_text(text: &str, width: usize, indent: &str) -> String {
    let mut result = String::new();
    let mut current_line = String::new();

    for word in text.split_whitespace() {
        if current_line.is_empty() {
            current_line = word.to_string();
        } else if current_line.len() + 1 + word.len() <= width {
            current_line.push(' ');
            current_line.push_str(word);
        } else {
            if !result.is_empty() {
                result.push('\n');
                result.push_str(indent);
            }
            result.push_str(&current_line);
            current_line = word.to_string();
        }
    }

    if !current_line.is_empty() {
        if !result.is_empty() {
            result.push('\n');
            result.push_str(indent);
        }
        result.push_str(&current_line);
    }

    result
}

/// Print issue detail.
pub fn print_show_issue(issue: &IssueDetail) {
    // Header
    let header = format!("Issue #{}: {}", issue.iid, issue.title);
    println!("{}", style(&header).bold());
    println!("{}", "━".repeat(header.len().min(80)));
    println!();

    // Metadata
    println!("Project:  {}", style(&issue.project_path).cyan());

    let state_styled = if issue.state == "opened" {
        style(&issue.state).green()
    } else {
        style(&issue.state).dim()
    };
    println!("State:    {}", state_styled);

    println!("Author:   @{}", issue.author_username);
    println!("Created:  {}", format_date(issue.created_at));
    println!("Updated:  {}", format_date(issue.updated_at));

    if issue.labels.is_empty() {
        println!("Labels:   {}", style("(none)").dim());
    } else {
        println!("Labels:   {}", issue.labels.join(", "));
    }

    if let Some(url) = &issue.web_url {
        println!("URL:      {}", style(url).dim());
    }

    println!();

    // Description
    println!("{}", style("Description:").bold());
    if let Some(desc) = &issue.description {
        let truncated = truncate(desc, 500);
        let wrapped = wrap_text(&truncated, 76, "  ");
        println!("  {}", wrapped);
    } else {
        println!("  {}", style("(no description)").dim());
    }

    println!();

    // Discussions
    let user_discussions: Vec<&DiscussionDetail> = issue
        .discussions
        .iter()
        .filter(|d| d.notes.iter().any(|n| !n.is_system))
        .collect();

    if user_discussions.is_empty() {
        println!("{}", style("Discussions: (none)").dim());
    } else {
        println!(
            "{}",
            style(format!("Discussions ({}):", user_discussions.len())).bold()
        );
        println!();

        for discussion in user_discussions {
            let user_notes: Vec<&NoteDetail> =
                discussion.notes.iter().filter(|n| !n.is_system).collect();

            if let Some(first_note) = user_notes.first() {
                // First note of discussion (not indented)
                println!(
                    "  {} ({}):",
                    style(format!("@{}", first_note.author_username)).cyan(),
                    format_date(first_note.created_at)
                );
                let wrapped = wrap_text(&truncate(&first_note.body, 300), 72, "    ");
                println!("    {}", wrapped);
                println!();

                // Replies (indented)
                for reply in user_notes.iter().skip(1) {
                    println!(
                        "      {} ({}):",
                        style(format!("@{}", reply.author_username)).cyan(),
                        format_date(reply.created_at)
                    );
                    let wrapped = wrap_text(&truncate(&reply.body, 300), 68, "        ");
                    println!("        {}", wrapped);
                    println!();
                }
            }
        }
    }
}

/// Print MR detail.
pub fn print_show_mr(mr: &MrDetail) {
    // Header with draft indicator
    let draft_prefix = if mr.draft { "[Draft] " } else { "" };
    let header = format!("MR !{}: {}{}", mr.iid, draft_prefix, mr.title);
    println!("{}", style(&header).bold());
    println!("{}", "━".repeat(header.len().min(80)));
    println!();

    // Metadata
    println!("Project:  {}", style(&mr.project_path).cyan());

    let state_styled = match mr.state.as_str() {
        "opened" => style(&mr.state).green(),
        "merged" => style(&mr.state).magenta(),
        "closed" => style(&mr.state).red(),
        _ => style(&mr.state).dim(),
    };
    println!("State:    {}", state_styled);

    println!(
        "Branches: {} -> {}",
        style(&mr.source_branch).cyan(),
        style(&mr.target_branch).yellow()
    );

    println!("Author:   @{}", mr.author_username);

    if !mr.assignees.is_empty() {
        println!(
            "Assignees: {}",
            mr.assignees
                .iter()
                .map(|a| format!("@{}", a))
                .collect::<Vec<_>>()
                .join(", ")
        );
    }

    if !mr.reviewers.is_empty() {
        println!(
            "Reviewers: {}",
            mr.reviewers
                .iter()
                .map(|r| format!("@{}", r))
                .collect::<Vec<_>>()
                .join(", ")
        );
    }

    println!("Created:  {}", format_date(mr.created_at));
    println!("Updated:  {}", format_date(mr.updated_at));

    if let Some(merged_at) = mr.merged_at {
        println!("Merged:   {}", format_date(merged_at));
    }

    if let Some(closed_at) = mr.closed_at {
        println!("Closed:   {}", format_date(closed_at));
    }

    if mr.labels.is_empty() {
        println!("Labels:   {}", style("(none)").dim());
    } else {
        println!("Labels:   {}", mr.labels.join(", "));
    }

    if let Some(url) = &mr.web_url {
        println!("URL:      {}", style(url).dim());
    }

    println!();

    // Description
    println!("{}", style("Description:").bold());
    if let Some(desc) = &mr.description {
        let truncated = truncate(desc, 500);
        let wrapped = wrap_text(&truncated, 76, "  ");
        println!("  {}", wrapped);
    } else {
        println!("  {}", style("(no description)").dim());
    }

    println!();

    // Discussions
    let user_discussions: Vec<&MrDiscussionDetail> = mr
        .discussions
        .iter()
        .filter(|d| d.notes.iter().any(|n| !n.is_system))
        .collect();

    if user_discussions.is_empty() {
        println!("{}", style("Discussions: (none)").dim());
    } else {
        println!(
            "{}",
            style(format!("Discussions ({}):", user_discussions.len())).bold()
        );
        println!();

        for discussion in user_discussions {
            let user_notes: Vec<&MrNoteDetail> =
                discussion.notes.iter().filter(|n| !n.is_system).collect();

            if let Some(first_note) = user_notes.first() {
                // Print DiffNote position context if present
                if let Some(pos) = &first_note.position {
                    print_diff_position(pos);
                }

                // First note of discussion (not indented)
                println!(
                    "  {} ({}):",
                    style(format!("@{}", first_note.author_username)).cyan(),
                    format_date(first_note.created_at)
                );
                let wrapped = wrap_text(&truncate(&first_note.body, 300), 72, "    ");
                println!("    {}", wrapped);
                println!();

                // Replies (indented)
                for reply in user_notes.iter().skip(1) {
                    println!(
                        "      {} ({}):",
                        style(format!("@{}", reply.author_username)).cyan(),
                        format_date(reply.created_at)
                    );
                    let wrapped = wrap_text(&truncate(&reply.body, 300), 68, "        ");
                    println!("        {}", wrapped);
                    println!();
                }
            }
        }
    }
}

/// Print DiffNote position context.
fn print_diff_position(pos: &DiffNotePosition) {
    let file = pos.new_path.as_ref().or(pos.old_path.as_ref());

    if let Some(file_path) = file {
        let line_str = match (pos.old_line, pos.new_line) {
            (Some(old), Some(new)) if old == new => format!(":{}", new),
            (Some(old), Some(new)) => format!(":{}→{}", old, new),
            (None, Some(new)) => format!(":+{}", new),
            (Some(old), None) => format!(":-{}", old),
            (None, None) => String::new(),
        };

        println!(
            "  {} {}{}",
            style("📍").dim(),
            style(file_path).yellow(),
            style(line_str).dim()
        );
    }
}

// ============================================================================
// JSON Output Structs (with ISO timestamps for machine consumption)
// ============================================================================

/// JSON output for issue detail.
#[derive(Serialize)]
pub struct IssueDetailJson {
    pub id: i64,
    pub iid: i64,
    pub title: String,
    pub description: Option<String>,
    pub state: String,
    pub author_username: String,
    pub created_at: String,
    pub updated_at: String,
    pub web_url: Option<String>,
    pub project_path: String,
    pub labels: Vec<String>,
    pub discussions: Vec<DiscussionDetailJson>,
}

/// JSON output for discussion detail.
#[derive(Serialize)]
pub struct DiscussionDetailJson {
    pub notes: Vec<NoteDetailJson>,
    pub individual_note: bool,
}

/// JSON output for note detail.
#[derive(Serialize)]
pub struct NoteDetailJson {
    pub author_username: String,
    pub body: String,
    pub created_at: String,
    pub is_system: bool,
}

impl From<&IssueDetail> for IssueDetailJson {
    fn from(issue: &IssueDetail) -> Self {
        Self {
            id: issue.id,
            iid: issue.iid,
            title: issue.title.clone(),
            description: issue.description.clone(),
            state: issue.state.clone(),
            author_username: issue.author_username.clone(),
            created_at: ms_to_iso(issue.created_at),
            updated_at: ms_to_iso(issue.updated_at),
            web_url: issue.web_url.clone(),
            project_path: issue.project_path.clone(),
            labels: issue.labels.clone(),
            discussions: issue.discussions.iter().map(|d| d.into()).collect(),
        }
    }
}

impl From<&DiscussionDetail> for DiscussionDetailJson {
    fn from(disc: &DiscussionDetail) -> Self {
        Self {
            notes: disc.notes.iter().map(|n| n.into()).collect(),
            individual_note: disc.individual_note,
        }
    }
}

impl From<&NoteDetail> for NoteDetailJson {
    fn from(note: &NoteDetail) -> Self {
        Self {
            author_username: note.author_username.clone(),
            body: note.body.clone(),
            created_at: ms_to_iso(note.created_at),
            is_system: note.is_system,
        }
    }
}

/// JSON output for MR detail.
#[derive(Serialize)]
pub struct MrDetailJson {
    pub id: i64,
    pub iid: i64,
    pub title: String,
    pub description: Option<String>,
    pub state: String,
    pub draft: bool,
    pub author_username: String,
    pub source_branch: String,
    pub target_branch: String,
    pub created_at: String,
    pub updated_at: String,
    pub merged_at: Option<String>,
    pub closed_at: Option<String>,
    pub web_url: Option<String>,
    pub project_path: String,
    pub labels: Vec<String>,
    pub assignees: Vec<String>,
    pub reviewers: Vec<String>,
    pub discussions: Vec<MrDiscussionDetailJson>,
}

/// JSON output for MR discussion detail.
#[derive(Serialize)]
pub struct MrDiscussionDetailJson {
    pub notes: Vec<MrNoteDetailJson>,
    pub individual_note: bool,
}

/// JSON output for MR note detail.
#[derive(Serialize)]
pub struct MrNoteDetailJson {
    pub author_username: String,
    pub body: String,
    pub created_at: String,
    pub is_system: bool,
    pub position: Option<DiffNotePosition>,
}

impl From<&MrDetail> for MrDetailJson {
    fn from(mr: &MrDetail) -> Self {
        Self {
            id: mr.id,
            iid: mr.iid,
            title: mr.title.clone(),
            description: mr.description.clone(),
            state: mr.state.clone(),
            draft: mr.draft,
            author_username: mr.author_username.clone(),
            source_branch: mr.source_branch.clone(),
            target_branch: mr.target_branch.clone(),
            created_at: ms_to_iso(mr.created_at),
            updated_at: ms_to_iso(mr.updated_at),
            merged_at: mr.merged_at.map(ms_to_iso),
            closed_at: mr.closed_at.map(ms_to_iso),
            web_url: mr.web_url.clone(),
            project_path: mr.project_path.clone(),
            labels: mr.labels.clone(),
            assignees: mr.assignees.clone(),
            reviewers: mr.reviewers.clone(),
            discussions: mr.discussions.iter().map(|d| d.into()).collect(),
        }
    }
}

impl From<&MrDiscussionDetail> for MrDiscussionDetailJson {
    fn from(disc: &MrDiscussionDetail) -> Self {
        Self {
            notes: disc.notes.iter().map(|n| n.into()).collect(),
            individual_note: disc.individual_note,
        }
    }
}

impl From<&MrNoteDetail> for MrNoteDetailJson {
    fn from(note: &MrNoteDetail) -> Self {
        Self {
            author_username: note.author_username.clone(),
            body: note.body.clone(),
            created_at: ms_to_iso(note.created_at),
            is_system: note.is_system,
            position: note.position.clone(),
        }
    }
}

/// Print issue detail as JSON.
pub fn print_show_issue_json(issue: &IssueDetail) {
    let json_result = IssueDetailJson::from(issue);
    match serde_json::to_string_pretty(&json_result) {
        Ok(json) => println!("{json}"),
        Err(e) => eprintln!("Error serializing to JSON: {e}"),
    }
}

/// Print MR detail as JSON.
pub fn print_show_mr_json(mr: &MrDetail) {
    let json_result = MrDetailJson::from(mr);
    match serde_json::to_string_pretty(&json_result) {
        Ok(json) => println!("{json}"),
        Err(e) => eprintln!("Error serializing to JSON: {e}"),
    }
}

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

    #[test]
    fn truncate_leaves_short_strings() {
        assert_eq!(truncate("short", 10), "short");
    }

    #[test]
    fn truncate_adds_ellipsis() {
        assert_eq!(truncate("this is a long string", 10), "this is...");
    }

    #[test]
    fn wrap_text_single_line() {
        assert_eq!(wrap_text("hello world", 80, "  "), "hello world");
    }

    #[test]
    fn wrap_text_multiple_lines() {
        let result = wrap_text("one two three four five", 10, "  ");
        assert!(result.contains('\n'));
    }

    #[test]
    fn format_date_extracts_date_part() {
        // 2024-01-15T00:00:00Z in milliseconds
        let ms = 1705276800000;
        let date = format_date(ms);
        assert!(date.starts_with("2024-01-15"));
    }
}