#!/usr/bin/env node
import fs from "fs";
import path from "path";
import { promisify } from "util";
import { glob } from "glob";
import OpenAI from "openai";
import dotenv from "dotenv";
import moment from "moment";
import { extractCodeBlock } from "./extractCodeBlock";
import { generateComment } from "./generateComment";

dotenv.config();

if (!process.env.OPENAI_API_KEY) {
  console.error("OPENAI_API_KEY is required.");
  process.exit(1);
}

const openai = new OpenAI({ apiKey: process.env.OPENAI_API_KEY });
const model = process.env.OPENAI_GPT_MODEL ?? "gpt-4o-mini";

const sharedPrompt = `Please maintain all logic, comments, imports.
Return the response as a code block with no additional explanation.
If no code changes are needed, return the original code block.`;

// Convert fs functions to Promises
const readFile = promisify(fs.readFile);
const writeFile = promisify(fs.writeFile);
const stat = promisify(fs.stat);

async function requiresProcessing(
  filePath: string,
  promptName: string
): Promise<boolean> {
  let fileContent = await readFile(filePath, "utf-8");

  // Check if file already has the generated comment
  const generatedComment = generateComment(promptName);
  if (fileContent.includes(generatedComment)) {
    return false;
  }
  return true;
}

// Process a single file
async function processFile(
  filePath: string,
  prompt: string,
  promptName: string,
  gptModel: string
) {
  const date = moment().format("YYYY-MM-DD");

  try {
    let fileContent = await readFile(filePath, "utf-8");

    // Check if file already has the generated comment
    const generatedComment = generateComment(promptName, date);
    if (fileContent.includes(generatedComment)) {
      console.log(`Skipping ${filePath} (already processed with this prompt)`);
      return;
    }

    const extension = path.extname(filePath).replace(".", "");

    // Concatenate prompt and file content
    const input = `${prompt}\n\n${sharedPrompt}\n\n\`\`\`${extension}\n${fileContent}\`\`\`\n`;

    console.log(`🔄 Processing: ${filePath}...`);
    // DEBUG:
    //console.log(input);

    // Send to OpenAI
    const completion = await openai.chat.completions.create({
      model: gptModel,
      messages: [{ role: "user", content: input }],
    });

    const response = completion.choices[0].message?.content ?? "";
    //console.log(response);

    // will throw if it doesn't include a single code block
    const extractedCode = extractCodeBlock(response);

    // Write the result back with a comment
    const updatedContent = `${generatedComment}\n${extractedCode}`;
    await writeFile(filePath, updatedContent, "utf-8");

    console.log(`✅ Finished`);
  } catch (error) {
    console.error(`❌ Error:`, error);
  }
}

interface IParams {
  promptPath: string;
  // defaults to basename of promptPath
  promptName: string;
  gptModel: string;
  sourcePath: string;
  includesText?: string;
  extensions?: string[];
  dryRun: boolean;
}

function getParams(): IParams {
  let promptPath: string | undefined;
  let promptName: string | undefined;
  let sourcePath: string | undefined;
  let includesText: string | undefined;
  let gptModel: string | undefined;
  let extensions: string[] | undefined;
  let dryRun = false;

  gptModel = process.env.OPENAI_GPT_MODEL;

  for (let i = 2; i < process.argv.length; i++) {
    const arg = process.argv[i];

    if (arg === "--dry") {
      dryRun = true;
    } else if (arg.startsWith("--name=")) {
      promptName = arg.slice("--name=".length);
    } else if (arg.startsWith("--model=")) {
      gptModel = arg.slice("--model=".length);
    } else if (arg.startsWith("--includes=")) {
      includesText = arg.slice("--includes=".length);
    } else if (arg.startsWith("--ext=")) {
      extensions = arg
        .slice("--ext=".length)
        .split(",")
        .map((ext) => ext.trim())
        .filter(Boolean);
    } else if (arg.startsWith("--")) {
      console.error(`Unknown option: ${arg}`);
      process.exit(1);
    } else if (!promptPath) {
      promptPath = arg;
      // get the prompt name from the file name if not provided
      if (!promptName) {
        // strips the extension and an optional ".review" suffix
        promptName = path.basename(promptPath).replace(".review", "");
      }
    } else if (!sourcePath) {
      sourcePath = arg;
    }
  }

  if (!gptModel) {
    console.error("Please set OPENAI_GPT_MODEL or use --model=<model>");
    process.exit(1);
  }

  if (!promptPath || !sourcePath || !promptName) {
    console.error(
      "Usage: ai-code-patterns [--includes=text] [--ext=ts,js,...] [--dry] [--name=promptName] [--model=gpt-4o] <promptPath> <sourcePath>"
    );
    process.exit(1);
  }

  return {
    promptPath,
    gptModel,
    promptName,
    sourcePath,
    includesText,
    extensions,
    dryRun,
  };
}

async function getFilePaths(params: IParams): Promise<string[]> {
  const { promptPath, sourcePath, includesText, extensions } = params;

  // Check that prompt file exists
  if (!fs.existsSync(promptPath)) {
    console.error(`Prompt file not found: ${promptPath}`);
    process.exit(1);
  }

  // Determine if sourcePath is a directory or file
  let files: string[] = [];

  try {
    const stats = await stat(sourcePath);
    if (stats.isDirectory()) {
      // If the user provided custom extensions, use them. Otherwise, use the default set.
      const defaultExtensions = [
        "ts",
        "js",
        "py",
        "java",
        "cpp",
        "swift",
        "kt",
        "go",
        "rb",
      ];
      const extsToUse =
        extensions && extensions.length > 0 ? extensions : defaultExtensions;

      // Build a glob pattern like: ./src/**/*.{ts,js,py,...}
      const fileExtensions =
        extsToUse.length > 1 ? `{${extsToUse.join(",")}}` : extsToUse[0];
      const globPattern = `${sourcePath}/**/*.${fileExtensions}`;
      files = await glob(globPattern, { nodir: true });
    } else {
      // Single file provided
      files = [sourcePath];
    }
  } catch (err) {
    console.error(`Invalid path: ${sourcePath}`);
    process.exit(1);
  }

  // If --includes=<text> was provided, filter files to only those containing that text
  if (includesText) {
    const filtered: string[] = [];
    for (const file of files) {
      try {
        const content = await readFile(file, "utf-8");
        if (content.includes(includesText)) {
          filtered.push(file);
        }
      } catch (e) {
        // If a file can't be read or doesn't exist, ignore it
      }
    }
    files = filtered;
  }

  return files;
}

// Main function
async function main() {
  const params = getParams();
  const { promptName, gptModel } = params;

  const files = await getFilePaths(params);
  const prompt = await readFile(params.promptPath, "utf-8");

  // Only keep files that require processing
  const filesToProcess: string[] = [];
  const filesAlreadyProcessed: string[] = [];
  for (const file of files) {
    const needed = await requiresProcessing(file, promptName);

    if (needed) {
      filesToProcess.push(file);
    } else {
      filesAlreadyProcessed.push(file);
    }
  }

  // For debugging, you can log which files you're processing
  filesAlreadyProcessed.forEach((file) => {
    console.log(`✅ Already processed: ${file}`);
  });
  filesToProcess.forEach((file) => {
    console.log(`🟡 Will process: ${file}`);
  });

  if (params.dryRun) {
    console.log("🛑 Dry run enabled, no files will be processed.");
    return;
  }

  // Process each file
  for (const file of filesToProcess) {
    await processFile(file, prompt, promptName, gptModel);
  }
}

// Run the script
main().catch(console.error);