//! Refactor-item creation and listing operations.

use std::path::Path;

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

/// Create a refactor work item and store it in the database.
///
/// Returns the refactor_id (e.g. `"5"`).
pub fn create_refactor_file(
    root: &Path,
    name: &str,
    description: Option<&str>,
    acceptance_criteria: Option<&[String]>,
    depends_on: Option<&[u32]>,
) -> Result<String, String> {
    let refactor_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 refactor_id = format!("{refactor_number}");

    let mut content = String::new();
    content.push_str("---\n");
    content.push_str("type: refactor\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!("# Refactor {refactor_number}: {name}\n\n"));
    content.push_str("## Current State\n\n");
    content.push_str("- TBD\n\n");
    content.push_str("## Desired State\n\n");
    if let Some(desc) = description {
        content.push_str(desc);
        content.push('\n');
    } else {
        content.push_str("- TBD\n");
    }
    content.push('\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("- [ ] Refactoring complete and all tests pass\n");
    }
    content.push('\n');
    content.push_str("## Out of Scope\n\n");
    content.push_str("- TBD\n");

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

    // Sync depends_on to the typed CRDT register.
    crate::crdt_state::set_depends_on(&refactor_id, depends_on.unwrap_or(&[]));

    // Story 933: typed CRDT register for item_type.
    crate::crdt_state::set_item_type(&refactor_id, Some("refactor"));

    Ok(refactor_id)
}

/// Returns true if the item stem is a refactor item.
///
/// Checks the slug-based ID format first (e.g. `"5_refactor_split_agents_rs"`),
/// then consults the typed CRDT `item_type` register for numeric-only IDs (933).
pub(super) fn is_refactor_item(stem: &str) -> bool {
    let after_num = stem.trim_start_matches(|c: char| c.is_ascii_digit());
    if after_num.starts_with("_refactor_") {
        return true;
    }
    if after_num.is_empty() {
        return crate::crdt_state::read_item(stem)
            .and_then(|v| v.item_type().map(str::to_string))
            .map(|t| t == "refactor")
            .unwrap_or(false);
    }
    false
}

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

    for item in crate::pipeline_state::read_all_typed() {
        if !matches!(item.stage, crate::pipeline_state::Stage::Backlog)
            || !is_refactor_item(&item.story_id.0)
        {
            continue;
        }
        let sid = item.story_id.0;
        let name = if item.name.is_empty() {
            sid.clone()
        } else {
            item.name
        };
        refactors.push((sid, name));
    }

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