/**
 * amux — Role Profiles and Team Templates
 *
 * Bundled role profile markdown and team templates, plus helpers to copy
 * them into project artifacts and resolve role instructions.
 *
 * Project-local role profiles live under artifacts/project/roles/<name>.md
 * and are the source of truth for an agent's prompt when RoleDefinition.profilePath
 * is set. Legacy roles without profilePath fall back to stored instructions.
 *
 * Pi-independent — file-based, no framework coupling.
 */

import { readFileSync, readdirSync, existsSync, writeFileSync, mkdirSync } from "node:fs";
import { fileURLToPath } from "node:url";
import { dirname, join } from "node:path";

import { sessionFile } from "./storage.ts";
import { type RoleDefinition, addRole } from "./registry.ts";

// ─── Bundled Template Paths ──────────────────────────────────

const moduleDir = dirname(fileURLToPath(import.meta.url));
const BUNDLED_ROLES_DIR = join(moduleDir, "..", "roles");
const BUNDLED_TEMPLATES_DIR = join(moduleDir, "..", "team-templates");

// ─── Types ───────────────────────────────────────────────────

export interface TeamTemplateRole {
  name: string; // role definition name
  template: string; // bundled role markdown template
  agentName?: string; // suggested agent name (shown during separate agent creation)
  workspace?: string; // suggested workspace policy (advisory only)
}

export interface TeamTemplate {
  name: string;
  description: string;
  roles: TeamTemplateRole[];
}

// ─── Bundled Template Discovery ──────────────────────────────

/** List available bundled role profile template names (without .md). */
export function listRoleTemplates(): string[] {
  try {
    return readdirSync(BUNDLED_ROLES_DIR)
      .filter((f) => f.endsWith(".md"))
      .map((f) => f.replace(/\.md$/, ""))
      .sort();
  } catch {
    return [];
  }
}

/** Read a bundled role template's markdown content, or null if missing. */
export function readRoleTemplate(templateName: string): string | null {
  const path = join(BUNDLED_ROLES_DIR, `${templateName}.md`);
  if (!existsSync(path)) return null;
  try {
    return readFileSync(path, "utf8");
  } catch {
    return null;
  }
}

/** List available bundled team templates. */
export function listTeamTemplates(): TeamTemplate[] {
  try {
    return readdirSync(BUNDLED_TEMPLATES_DIR)
      .filter((f) => f.endsWith(".json"))
      .map((f) => {
        try {
          return JSON.parse(readFileSync(join(BUNDLED_TEMPLATES_DIR, f), "utf8")) as TeamTemplate;
        } catch {
          return null;
        }
      })
      .filter((t): t is TeamTemplate => t !== null);
  } catch {
    return [];
  }
}

/** Get a single bundled team template by name, or null. */
export function getTeamTemplate(name: string): TeamTemplate | null {
  return listTeamTemplates().find((t) => t.name === name) ?? null;
}

// ─── Project-Local Profile Paths ─────────────────────────────

/** Conventional relative path for a project-local role profile. */
export function roleProfileRelPath(roleName: string): string {
  return `roles/${roleName}.md`;
}

/** Resolve a role profile relative path to a full session path. */
export function roleProfileFullPath(session: string, relPath: string): string {
  return sessionFile(session, "artifacts", "project", relPath);
}

// ─── Description Extraction ──────────────────────────────────

/** Extract a short description from role markdown (first heading or Mission line). */
function extractDescription(content: string): string {
  const lines = content.split("\n");
  // Prefer the line after a "## Mission" heading
  const missionIdx = lines.findIndex((l) => /^##\s+Mission/i.test(l));
  if (missionIdx >= 0) {
    for (let i = missionIdx + 1; i < lines.length; i++) {
      const t = lines[i]!.trim();
      if (t) return t.slice(0, 100);
    }
  }
  // Fall back to first H1
  const h1 = lines.find((l) => /^#\s+/.test(l));
  if (h1) return h1.replace(/^#\s+/, "").trim();
  return "";
}

// ─── Copy + Apply ────────────────────────────────────────────

/**
 * Copy a bundled role template into project artifacts.
 * Does NOT overwrite an existing customized file unless force is true.
 * Returns the relative profilePath, or null if the template doesn't exist.
 */
export function copyRoleProfile(
  session: string,
  templateName: string,
  roleName: string,
  force = false,
): string | null {
  const content = readRoleTemplate(templateName);
  if (content === null) return null;

  const relPath = roleProfileRelPath(roleName);
  const fullPath = roleProfileFullPath(session, relPath);

  if (existsSync(fullPath) && !force) {
    return relPath; // preserve customized file
  }

  mkdirSync(dirname(fullPath), { recursive: true });
  writeFileSync(fullPath, content, "utf8");
  return relPath;
}

/**
 * Resolve an agent's role instructions.
 * If profilePath is set and the file exists, the markdown file is the source
 * of truth. Otherwise fall back to the stored instructions (legacy roles).
 */
export function resolveRoleInstructions(session: string, role: RoleDefinition): string {
  if (role.profilePath) {
    const fullPath = roleProfileFullPath(session, role.profilePath);
    if (existsSync(fullPath)) {
      try {
        const content = readFileSync(fullPath, "utf8").trim();
        if (content) return content;
      } catch {
        // fall through to stored instructions
      }
    }
  }
  return role.instructions;
}

/**
 * Apply a team template: copy role profiles into the project and register
 * role definitions. Roles only — does NOT create agents or workspaces.
 * Existing customized role files are preserved unless force is true.
 *
 * @returns The applied role names and the template, or null if not found.
 */
export async function applyTeamTemplate(
  session: string,
  templateName: string,
  force = false,
): Promise<{ applied: string[]; template: TeamTemplate } | null> {
  const template = getTeamTemplate(templateName);
  if (!template) return null;

  const applied: string[] = [];
  for (const spec of template.roles) {
    const content = readRoleTemplate(spec.template);
    if (content === null) continue;

    const relPath = copyRoleProfile(session, spec.template, spec.name, force);
    if (!relPath) continue;

    await addRole(session, {
      name: spec.name,
      description: extractDescription(content),
      instructions: content.trim(), // cached fallback; profilePath is source of truth
      profilePath: relPath,
      templateName: spec.template,
    });
    applied.push(spec.name);
  }

  return { applied, template };
}