/**
 * Superpowers plugin for OpenCode.ai
 *
 * Provides custom tools for loading and discovering skills,
 * with prompt generation for agent configuration.
 */

import path from 'path';
import fs from 'fs';
import os from 'os';
import { fileURLToPath } from 'url';
import { tool } from '@opencode-ai/plugin/tool';
import * as skillsCore from '../../lib/skills-core.js';

const __dirname = path.dirname(fileURLToPath(import.meta.url));

// Normalize a path: trim whitespace, expand ~, resolve to absolute
const normalizePath = (p, homeDir) => {
  if (!p || typeof p !== 'string') return null;
  let normalized = p.trim();
  if (!normalized) return null;
  // Expand ~ to home directory
  if (normalized.startsWith('~/')) {
    normalized = path.join(homeDir, normalized.slice(2));
  } else if (normalized === '~') {
    normalized = homeDir;
  }
  // Resolve to absolute path
  return path.resolve(normalized);
};

export const SuperpowersPlugin = async ({ client, directory }) => {
  const homeDir = os.homedir();
  const projectSkillsDir = path.join(directory, '.opencode/skills');
  // Derive superpowers skills dir from plugin location (works for both symlinked and local installs)
  const superpowersSkillsDir = path.resolve(__dirname, '../../skills');
  // Respect OPENCODE_CONFIG_DIR if set, otherwise fall back to default
  const envConfigDir = normalizePath(process.env.OPENCODE_CONFIG_DIR, homeDir);
  const configDir = envConfigDir || path.join(homeDir, '.config/opencode');
  const personalSkillsDir = path.join(configDir, 'skills');

  // Helper to generate bootstrap content
  const getBootstrapContent = (compact = false) => {
    const usingSuperpowersPath = skillsCore.resolveSkillPath('using-superpowers', superpowersSkillsDir, personalSkillsDir);
    if (!usingSuperpowersPath) return null;

    const fullContent = fs.readFileSync(usingSuperpowersPath.skillFile, 'utf8');
    const content = skillsCore.stripFrontmatter(fullContent);

    const toolMapping = compact
      ? `**Tool Mapping:** TodoWrite->update_plan, Task->@mention, Skill->use_skill

**Skills naming (priority order):** project: > personal > superpowers:`
      : `**Tool Mapping for OpenCode:**
When skills reference tools you don't have, substitute OpenCode equivalents:
- \`TodoWrite\` → \`update_plan\`
- \`Task\` tool with subagents → Use OpenCode's subagent system (@mention)
- \`Skill\` tool → \`use_skill\` custom tool
- \`Read\`, \`Write\`, \`Edit\`, \`Bash\` → Your native tools

**Skills naming (priority order):**
- Project skills: \`project:skill-name\` (in .opencode/skills/)
- Personal skills: \`skill-name\` (in ${configDir}/skills/)
- Superpowers skills: \`superpowers:skill-name\`
- Project skills override personal, which override superpowers when names match`;

    return `<EXTREMELY_IMPORTANT>
You have superpowers.

**IMPORTANT: The using-superpowers skill content is included below. It is ALREADY LOADED - you are currently following it. Do NOT use the use_skill tool to load "using-superpowers" - that would be redundant. Use use_skill only for OTHER skills.**

${content}

${toolMapping}
</EXTREMELY_IMPORTANT>`;
  };

  // Helper to inject bootstrap via session.prompt
  const injectBootstrap = async (sessionID, compact = false) => {
    const bootstrapContent = getBootstrapContent(compact);
    if (!bootstrapContent) return false;

    try {
      await client.session.prompt({
        path: { id: sessionID },
        body: {
          noReply: true,
          parts: [{ type: "text", text: bootstrapContent, synthetic: true }]
        }
      });
      return true;
    } catch (err) {
      return false;
    }
  };

  return {
    tool: {
      use_skill: tool({
        description: 'Load and read a specific skill to guide your work. Skills contain proven workflows, mandatory processes, and expert techniques.',
        args: {
          skill_name: tool.schema.string().describe('Name of the skill to load (e.g., "superpowers:brainstorming", "my-custom-skill", or "project:my-skill")')
        },
        execute: async (args, context) => {
          const { skill_name } = args;

          // Resolve with priority: project > personal > superpowers
          // Check for project: prefix first
          const forceProject = skill_name.startsWith('project:');
          const actualSkillName = forceProject ? skill_name.replace(/^project:/, '') : skill_name;

          let resolved = null;

          // Try project skills first (if project: prefix or no prefix)
          if (forceProject || !skill_name.startsWith('superpowers:')) {
            const projectPath = path.join(projectSkillsDir, actualSkillName);
            const projectSkillFile = path.join(projectPath, 'SKILL.md');
            if (fs.existsSync(projectSkillFile)) {
              resolved = {
                skillFile: projectSkillFile,
                sourceType: 'project',
                skillPath: actualSkillName
              };
            }
          }

          // Fall back to personal/superpowers resolution
          if (!resolved && !forceProject) {
            resolved = skillsCore.resolveSkillPath(skill_name, superpowersSkillsDir, personalSkillsDir);
          }

          if (!resolved) {
            return `Error: Skill "${skill_name}" not found.\n\nRun find_skills to see available skills.`;
          }

          const fullContent = fs.readFileSync(resolved.skillFile, 'utf8');
          const { name, description } = skillsCore.extractFrontmatter(resolved.skillFile);
          const content = skillsCore.stripFrontmatter(fullContent);
          const skillDirectory = path.dirname(resolved.skillFile);

          const skillHeader = `# ${name || skill_name}
# ${description || ''}
# Supporting tools and docs are in ${skillDirectory}
# ============================================`;

          // Insert as user message with noReply for persistence across compaction
          try {
            await client.session.prompt({
              path: { id: context.sessionID },
              body: {
                agent: context.agent,
                noReply: true,
                parts: [
                  { type: "text", text: `Loading skill: ${name || skill_name}`, synthetic: true },
                  { type: "text", text: `${skillHeader}\n\n${content}`, synthetic: true }
                ]
              }
            });
          } catch (err) {
            // Fallback: return content directly if message insertion fails
            return `${skillHeader}\n\n${content}`;
          }

          return `Launching skill: ${name || skill_name}`;
        }
      }),
      find_skills: tool({
        description: 'List all available skills in the project, personal, and superpowers skill libraries.',
        args: {},
        execute: async (args, context) => {
          const projectSkills = skillsCore.findSkillsInDir(projectSkillsDir, 'project', 3);
          const personalSkills = skillsCore.findSkillsInDir(personalSkillsDir, 'personal', 3);
          const superpowersSkills = skillsCore.findSkillsInDir(superpowersSkillsDir, 'superpowers', 3);

          // Priority: project > personal > superpowers
          const allSkills = [...projectSkills, ...personalSkills, ...superpowersSkills];

          if (allSkills.length === 0) {
            return `No skills found. Install superpowers skills to ${superpowersSkillsDir}/ or add personal skills to ${personalSkillsDir}/`;
          }

          let output = 'Available skills:\n\n';

          for (const skill of allSkills) {
            let namespace;
            switch (skill.sourceType) {
              case 'project':
                namespace = 'project:';
                break;
              case 'personal':
                namespace = '';
                break;
              default:
                namespace = 'superpowers:';
            }
            const skillName = skill.name || path.basename(skill.path);

            output += `${namespace}${skillName}\n`;
            if (skill.description) {
              output += `  ${skill.description}\n`;
            }
            output += `  Directory: ${skill.path}\n\n`;
          }

          return output;
        }
      })
    },
    event: async ({ event }) => {
      // Extract sessionID from various event structures
      const getSessionID = () => {
        return event.properties?.info?.id ||
               event.properties?.sessionID ||
               event.session?.id;
      };

      // Inject bootstrap at session creation (before first user message)
      if (event.type === 'session.created') {
        const sessionID = getSessionID();
        if (sessionID) {
          await injectBootstrap(sessionID, false);
        }
      }

      // Re-inject bootstrap after context compaction (compact version to save tokens)
      if (event.type === 'session.compacted') {
        const sessionID = getSessionID();
        if (sessionID) {
          await injectBootstrap(sessionID, true);
        }
      }
    }
  };
};