import type { AgentTool } from "@mariozechner/pi-agent-core";
import { type Static, Type } from "@sinclair/typebox";
import { spawnSync } from "child_process";
import { existsSync } from "fs";
import { globSync } from "glob";
import path from "path";
import { ensureTool } from "../../utils/tools-manager.js";
import { resolveToCwd } from "./path-utils.js";
import {
  DEFAULT_MAX_BYTES,
  formatSize,
  type TruncationResult,
  truncateHead,
} from "./truncate.js";

const findSchema = Type.Object({
  pattern: Type.String({
    description:
      "Glob pattern to match files, e.g. '*.ts', '**/*.json', or 'src/**/*.spec.ts'",
  }),
  path: Type.Optional(
    Type.String({
      description: "Directory to search in (default: current directory)",
    }),
  ),
  limit: Type.Optional(
    Type.Number({ description: "Maximum number of results (default: 1000)" }),
  ),
});

export type FindToolInput = Static<typeof findSchema>;

const DEFAULT_LIMIT = 1000;

export interface FindToolDetails {
  truncation?: TruncationResult;
  resultLimitReached?: number;
}

/**
 * Pluggable operations for the find tool.
 * Override these to delegate file search to remote systems (e.g., SSH).
 */
export interface FindOperations {
  /** Check if path exists */
  exists: (absolutePath: string) => Promise<boolean> | boolean;
  /** Find files matching glob pattern. Returns relative paths. */
  glob: (
    pattern: string,
    cwd: string,
    options: { ignore: string[]; limit: number },
  ) => Promise<string[]> | string[];
}

const defaultFindOperations: FindOperations = {
  exists: existsSync,
  glob: (_pattern, _searchCwd, _options) => {
    // This is a placeholder - actual fd execution happens in execute
    return [];
  },
};

export interface FindToolOptions {
  /** Custom operations for find. Default: local filesystem + fd */
  operations?: FindOperations;
}

export function createFindTool(
  cwd: string,
  options?: FindToolOptions,
): AgentTool<typeof findSchema> {
  const customOps = options?.operations;

  return {
    name: "find",
    label: "find",
    description: `Search for files by glob pattern. Returns matching file paths relative to the search directory. Respects .gitignore. Output is truncated to ${DEFAULT_LIMIT} results or ${DEFAULT_MAX_BYTES / 1024}KB (whichever is hit first).`,
    parameters: findSchema,
    execute: async (
      _toolCallId: string,
      {
        pattern,
        path: searchDir,
        limit,
      }: { pattern: string; path?: string; limit?: number },
      signal?: AbortSignal,
    ) => {
      return new Promise((resolve, reject) => {
        if (signal?.aborted) {
          reject(new Error("Operation aborted"));
          return;
        }

        const onAbort = () => reject(new Error("Operation aborted"));
        signal?.addEventListener("abort", onAbort, { once: true });

        (async () => {
          try {
            const searchPath = resolveToCwd(searchDir || ".", cwd);
            const effectiveLimit = limit ?? DEFAULT_LIMIT;
            const ops = customOps ?? defaultFindOperations;

            // If custom operations provided with glob, use that
            if (customOps?.glob) {
              if (!(await ops.exists(searchPath))) {
                reject(new Error(`Path not found: ${searchPath}`));
                return;
              }

              const results = await ops.glob(pattern, searchPath, {
                ignore: ["**/node_modules/**", "**/.git/**"],
                limit: effectiveLimit,
              });

              signal?.removeEventListener("abort", onAbort);

              if (results.length === 0) {
                resolve({
                  content: [
                    { type: "text", text: "No files found matching pattern" },
                  ],
                  details: undefined,
                });
                return;
              }

              // Relativize paths
              const relativized = results.map((p) => {
                if (p.startsWith(searchPath)) {
                  return p.slice(searchPath.length + 1);
                }
                return path.relative(searchPath, p);
              });

              const resultLimitReached = relativized.length >= effectiveLimit;
              const rawOutput = relativized.join("\n");
              const truncation = truncateHead(rawOutput, {
                maxLines: Number.MAX_SAFE_INTEGER,
              });

              let resultOutput = truncation.content;
              const details: FindToolDetails = {};
              const notices: string[] = [];

              if (resultLimitReached) {
                notices.push(`${effectiveLimit} results limit reached`);
                details.resultLimitReached = effectiveLimit;
              }

              if (truncation.truncated) {
                notices.push(`${formatSize(DEFAULT_MAX_BYTES)} limit reached`);
                details.truncation = truncation;
              }

              if (notices.length > 0) {
                resultOutput += `\n\n[${notices.join(". ")}]`;
              }

              resolve({
                content: [{ type: "text", text: resultOutput }],
                details: Object.keys(details).length > 0 ? details : undefined,
              });
              return;
            }

            // Default: use fd
            const fdPath = await ensureTool("fd", true);
            if (!fdPath) {
              reject(
                new Error("fd is not available and could not be downloaded"),
              );
              return;
            }

            // Build fd arguments
            const args: string[] = [
              "--glob",
              "--color=never",
              "--hidden",
              "--max-results",
              String(effectiveLimit),
            ];

            // Include .gitignore files
            const gitignoreFiles = new Set<string>();
            const rootGitignore = path.join(searchPath, ".gitignore");
            if (existsSync(rootGitignore)) {
              gitignoreFiles.add(rootGitignore);
            }

            try {
              const nestedGitignores = globSync("**/.gitignore", {
                cwd: searchPath,
                dot: true,
                absolute: true,
                ignore: ["**/node_modules/**", "**/.git/**"],
              });
              for (const file of nestedGitignores) {
                gitignoreFiles.add(file);
              }
            } catch {
              // Ignore glob errors
            }

            for (const gitignorePath of gitignoreFiles) {
              args.push("--ignore-file", gitignorePath);
            }

            args.push(pattern, searchPath);

            const result = spawnSync(fdPath, args, {
              encoding: "utf-8",
              maxBuffer: 10 * 1024 * 1024,
            });

            signal?.removeEventListener("abort", onAbort);

            if (result.error) {
              reject(new Error(`Failed to run fd: ${result.error.message}`));
              return;
            }

            const output = result.stdout?.trim() || "";

            if (result.status !== 0) {
              const errorMsg =
                result.stderr?.trim() || `fd exited with code ${result.status}`;
              if (!output) {
                reject(new Error(errorMsg));
                return;
              }
            }

            if (!output) {
              resolve({
                content: [
                  { type: "text", text: "No files found matching pattern" },
                ],
                details: undefined,
              });
              return;
            }

            const lines = output.split("\n");
            const relativized: string[] = [];

            for (const rawLine of lines) {
              const line = rawLine.replace(/\r$/, "").trim();
              if (!line) continue;

              const hadTrailingSlash =
                line.endsWith("/") || line.endsWith("\\");
              let relativePath = line;
              if (line.startsWith(searchPath)) {
                relativePath = line.slice(searchPath.length + 1);
              } else {
                relativePath = path.relative(searchPath, line);
              }

              if (hadTrailingSlash && !relativePath.endsWith("/")) {
                relativePath += "/";
              }

              relativized.push(relativePath);
            }

            const resultLimitReached = relativized.length >= effectiveLimit;
            const rawOutput = relativized.join("\n");
            const truncation = truncateHead(rawOutput, {
              maxLines: Number.MAX_SAFE_INTEGER,
            });

            let resultOutput = truncation.content;
            const details: FindToolDetails = {};
            const notices: string[] = [];

            if (resultLimitReached) {
              notices.push(
                `${effectiveLimit} results limit reached. Use limit=${effectiveLimit * 2} for more, or refine pattern`,
              );
              details.resultLimitReached = effectiveLimit;
            }

            if (truncation.truncated) {
              notices.push(`${formatSize(DEFAULT_MAX_BYTES)} limit reached`);
              details.truncation = truncation;
            }

            if (notices.length > 0) {
              resultOutput += `\n\n[${notices.join(". ")}]`;
            }

            resolve({
              content: [{ type: "text", text: resultOutput }],
              details: Object.keys(details).length > 0 ? details : undefined,
            });
          } catch (e: any) {
            signal?.removeEventListener("abort", onAbort);
            reject(e);
          }
        })();
      });
    },
  };
}

/** Default find tool using process.cwd() - for backwards compatibility */
export const findTool = createFindTool(process.cwd());