//! Bug-item creation and listing operations.

use crate::io::story_metadata::parse_front_matter;
use std::path::Path;

use super::super::{next_item_number, slugify_name, write_story_content};

/// Create a bug file and store it in the database.
///
/// Also writes to the filesystem for backwards compatibility during migration.
/// Returns the bug_id (e.g. `"4"`).
#[allow(clippy::too_many_arguments)]
pub fn create_bug_file(
    root: &Path,
    name: &str,
    description: &str,
    steps_to_reproduce: &str,
    actual_result: &str,
    expected_result: &str,
    acceptance_criteria: Option<&[String]>,
    depends_on: Option<&[u32]>,
) -> Result<String, String> {
    let bug_number = next_item_number(root)?;
    let slug = slugify_name(name);

    if slug.is_empty() {
        return Err("Name must contain at least one alphanumeric character.".to_string());
    }

    let bug_id = format!("{bug_number}");

    let mut content = String::new();
    content.push_str("---\n");
    content.push_str("type: bug\n");
    content.push_str(&format!("name: \"{}\"\n", name.replace('"', "\\\"")));
    if let Some(deps) = depends_on.filter(|d| !d.is_empty()) {
        let nums: Vec<String> = deps.iter().map(|n| n.to_string()).collect();
        content.push_str(&format!("depends_on: [{}]\n", nums.join(", ")));
    }
    content.push_str("---\n\n");
    content.push_str(&format!("# Bug {bug_number}: {name}\n\n"));
    content.push_str("## Description\n\n");
    content.push_str(description);
    content.push_str("\n\n");
    content.push_str("## How to Reproduce\n\n");
    content.push_str(steps_to_reproduce);
    content.push_str("\n\n");
    content.push_str("## Actual Result\n\n");
    content.push_str(actual_result);
    content.push_str("\n\n");
    content.push_str("## Expected Result\n\n");
    content.push_str(expected_result);
    content.push_str("\n\n");
    content.push_str("## Acceptance Criteria\n\n");
    if let Some(criteria) = acceptance_criteria {
        for criterion in criteria {
            content.push_str(&format!("- [ ] {criterion}\n"));
        }
    } else {
        content.push_str("- [ ] Bug is fixed and verified\n");
    }

    // Write to database content store and CRDT.
    write_story_content(root, &bug_id, "1_backlog", &content);

    Ok(bug_id)
}

/// Returns true if the item stem is a bug item.
///
/// Checks the slug-based ID format first (e.g. `"4_bug_login_crash"`), then
/// falls back to reading `type: bug` from the content store for numeric-only IDs.
pub(super) fn is_bug_item(stem: &str) -> bool {
    let after_num = stem.trim_start_matches(|c: char| c.is_ascii_digit());
    if after_num.starts_with("_bug_") {
        return true;
    }
    // Numeric-only ID: check content store front matter.
    if after_num.is_empty() {
        return crate::db::read_content(stem)
            .and_then(|c| parse_front_matter(&c).ok())
            .and_then(|m| m.item_type)
            .map(|t| t == "bug")
            .unwrap_or(false);
    }
    false
}

/// Extract bug name from content (heading or front matter).
pub(super) fn extract_bug_name_from_content(content: &str) -> Option<String> {
    // Try front matter first.
    if let Ok(meta) = parse_front_matter(content)
        && let Some(name) = meta.name
    {
        return Some(name);
    }
    // Fallback: heading.
    for line in content.lines() {
        if let Some(rest) = line.strip_prefix("# Bug ")
            && let Some(colon_pos) = rest.find(": ")
        {
            return Some(rest[colon_pos + 2..].to_string());
        }
    }
    None
}

/// List all open bugs from CRDT + content store.
///
/// Returns a sorted list of `(bug_id, name)` pairs.
pub fn list_bug_files(_root: &Path) -> Result<Vec<(String, String)>, String> {
    let mut bugs = Vec::new();

    for item in crate::pipeline_state::read_all_typed() {
        if !matches!(item.stage, crate::pipeline_state::Stage::Backlog)
            || !is_bug_item(&item.story_id.0)
        {
            continue;
        }
        let sid = item.story_id.0;
        let name = if item.name.is_empty() {
            None
        } else {
            Some(item.name)
        }
        .or_else(|| crate::db::read_content(&sid).and_then(|c| extract_bug_name_from_content(&c)))
        .unwrap_or_else(|| sid.clone());
        bugs.push((sid, name));
    }

    bugs.sort_by(|a, b| a.0.cmp(&b.0));
    Ok(bugs)
}