import { loadTextFile, saveTextFile } from "./file-service.js";
import { toolDbFilePath, toolDbTranscriptPath } from "./path-model.js";

function stableTextHash(text) {
  let hash = 0x811c9dc5;
  for (let index = 0; index < text.length; index += 1) {
    hash ^= text.charCodeAt(index);
    hash = Math.imul(hash, 0x01000193) >>> 0;
  }
  return hash.toString(16).padStart(8, "0");
}

function displayOpfsPath(path) {
  return path.startsWith("linuxcnc/") ? path.slice("linuxcnc".length) : `/${path}`;
}

export function createToolDbStorePaths(machineId, {
  dbFilename = "db_nonran_file",
  runId = "run-1",
  transcriptFilename = "transcript.json",
} = {}) {
  return {
    dbFile: toolDbFilePath(machineId, dbFilename),
    transcript: toolDbTranscriptPath(machineId, runId, transcriptFilename),
  };
}

export async function saveToolDbFile(machineId, text, options = {}) {
  const path = options.path ?? toolDbFilePath(machineId, options.filename);
  await saveTextFile(path, text, options.storage);
  return {
    opfsPath: path,
    displayPath: displayOpfsPath(path),
    dbFileHash: stableTextHash(text),
    savedText: text,
  };
}

export async function loadToolDbFile(machineId, options = {}) {
  const path = options.path ?? toolDbFilePath(machineId, options.filename);
  const text = await loadTextFile(path, options.storage);
  return {
    opfsPath: path,
    displayPath: displayOpfsPath(path),
    dbFileHash: stableTextHash(text),
    text,
  };
}

export async function saveToolDbTranscript(machineId, runId, transcript, options = {}) {
  if (!Array.isArray(transcript)) {
    throw new Error("transcript must be an array.");
  }
  const path = options.path ?? toolDbTranscriptPath(machineId, runId, options.filename);
  const text = JSON.stringify({
    schema: "linuxcnc.toolDbProcessTranscript.v1",
    transcript,
  }, null, 2);
  await saveTextFile(path, text, options.storage);
  return {
    opfsPath: path,
    displayPath: displayOpfsPath(path),
    transcriptHash: stableTextHash(text),
    text,
  };
}

export async function loadToolDbTranscript(machineId, runId, options = {}) {
  const path = options.path ?? toolDbTranscriptPath(machineId, runId, options.filename);
  const text = await loadTextFile(path, options.storage);
  const payload = JSON.parse(text);
  return {
    opfsPath: path,
    displayPath: displayOpfsPath(path),
    transcriptHash: stableTextHash(text),
    payload,
  };
}