import path from 'path';
import fs from 'fs';
import { getWorkspacePath } from '../config/paths.js';
import { ToolResult } from '../types.js';

function isPathInsideDir(base: string, target: string): boolean {
  const resolvedBase = path.resolve(base);
  const resolvedTarget = path.resolve(target);
  if (resolvedBase === resolvedTarget) return true;
  const rel = path.relative(resolvedBase, resolvedTarget);
  return rel !== '' && !rel.startsWith('..') && !path.isAbsolute(rel);
}

function formatTable(columns: string[], rows: any[][]): string {
  if (!rows.length) return '(no rows)';
  const widths = columns.map((c, i) =>
    Math.min(40, Math.max(c.length, ...rows.map(r => String(r[i] ?? '').length)))
  );
  const pad = (s: string, w: number) => String(s ?? '').padEnd(w).slice(0, w);
  const sep = widths.map(w => '-'.repeat(w)).join('-+-');
  const header = columns.map((c, i) => pad(c, widths[i])).join(' | ');
  return [header, sep, ...rows.map(r => r.map((cell, i) => pad(String(cell ?? ''), widths[i])).join(' | '))].join('\n');
}

const WRITE_RE = /^\s*(INSERT|UPDATE|DELETE|CREATE|DROP|ALTER|REPLACE|TRUNCATE|ATTACH|DETACH)\s/i;

export const sqliteTool = {
  name: 'sqlite_query',
  description: 'Execute SQL queries on a SQLite database file inside the workspace. SELECT queries are allowed by default. Set write=true to run INSERT/UPDATE/DELETE/CREATE/DROP.',
  schema: {
    db_path:  'Path to the .db file (relative to workspace, or absolute)',
    query:    'SQL query to execute',
    write:    'Allow write queries: INSERT/UPDATE/DELETE/CREATE/DROP (default: false)',
    max_rows: 'Maximum rows to return for SELECT (default: 100)',
  },
  jsonSchema: {
    type: 'object',
    properties: {
      db_path:  { type: 'string',  description: 'Path to the SQLite database file' },
      query:    { type: 'string',  description: 'SQL query' },
      write:    { type: 'boolean', description: 'Allow write operations (default: false)' },
      max_rows: { type: 'number',  description: 'Max rows returned for SELECT (default: 100)' },
    },
    required: ['db_path', 'query'],
    additionalProperties: false,
  },
  execute: async (args: any): Promise<ToolResult> => {
    const dbPath = String(args?.db_path || '').trim();
    const query  = String(args?.query   || '').trim();
    if (!dbPath) return { success: false, error: 'db_path is required' };
    if (!query)  return { success: false, error: 'query is required' };

    const workspacePath = getWorkspacePath(args);
    let resolved: string;
    if (path.isAbsolute(dbPath)) {
      resolved = dbPath;
    } else {
      resolved = path.resolve(workspacePath, dbPath);
      if (!isPathInsideDir(workspacePath, resolved)) {
        return { success: false, error: 'relative db_path must stay inside workspace (use absolute path for shared databases)' };
      }
    }

    const allowWrite = Boolean(args?.write);
    const isWrite = WRITE_RE.test(query);
    if (isWrite && !allowWrite) {
      return { success: false, error: 'Write query requires write=true. Set write=true to allow INSERT/UPDATE/DELETE/CREATE.' };
    }

    let Database: any;
    try {
      const mod = await import('better-sqlite3');
      Database = mod.default ?? mod;
    } catch (err: any) {
      return { success: false, error: `better-sqlite3 unavailable: ${err.message}` };
    }

    let db: any;
    try {
      db = new Database(resolved, { readonly: !allowWrite });
    } catch (err: any) {
      return { success: false, error: `Cannot open database: ${err.message}` };
    }

    try {
      const maxRows = Math.min(1_000, Math.max(1, Number(args?.max_rows ?? 100)));
      const stmt = db.prepare(query);

      if (isWrite || !query.trim().toUpperCase().startsWith('SELECT')) {
        const info = stmt.run();
        return {
          success: true,
          stdout: `OK\nRows affected: ${info.changes} | Last insert rowid: ${info.lastInsertRowid}`,
          data: { changes: info.changes, lastInsertRowid: info.lastInsertRowid },
        };
      }

      const rows: any[] = stmt.all().slice(0, maxRows);
      if (!rows.length) return { success: true, stdout: '(no rows returned)', data: { rows: [] } };

      const columns = Object.keys(rows[0]);
      const table = formatTable(columns, rows.map((r: any) => columns.map(c => r[c])));

      let total = rows.length;
      try {
        // Wrap query in subquery to get total row count
        const countRow = db.prepare(`SELECT COUNT(*) AS _cnt FROM (${query})`).get();
        total = Number(countRow?._cnt ?? rows.length);
      } catch {}

      const note = rows.length < total ? `\n\n[Showing ${rows.length} of ${total} rows. Use max_rows to increase limit.]` : '';
      return {
        success: true,
        stdout: table + note,
        data: { columns, row_count: rows.length, total, rows },
      };
    } catch (err: any) {
      return { success: false, error: `Query error: ${err.message}` };
    } finally {
      try { db.close(); } catch {}
    }
  },
};