import { spawn } from "node:child_process";
import { createHash } from "node:crypto";
import { mkdtemp, readFile, rm, stat, writeFile, mkdir } from "node:fs/promises";
import os from "node:os";
import path from "node:path";
import { fileURLToPath } from "node:url";

const scriptDirectory = path.dirname(fileURLToPath(import.meta.url));
const projectRoot = path.resolve(scriptDirectory, "../..");
const recipeFile = path.join(scriptDirectory, "recipes", "forsaken-abbey-population.json");
const recipe = JSON.parse(await readFile(recipeFile, "utf8"));
const resolveProject = (value) => path.resolve(projectRoot, value);
const sourceRoot = path.resolve(
  process.env[recipe.source.rootEnvironmentVariable]
    ?? path.join(projectRoot, recipe.source.relativeDefault),
);
const server = process.env[recipe.source.serverEnvironmentVariable] ?? recipe.source.serverDefault;
const globalBackup = resolveProject(recipe.source.backups.global);
const objectBackup = resolveProject(recipe.source.backups.objects);
const snapshotFile = resolveProject(recipe.files.snapshot);
const powershellScript = path.join(scriptDirectory, "refresh-forsaken-population.ps1");

function run(executable, argumentsList, label) {
  return new Promise((resolve, reject) => {
    console.log("\n[runewaker-forensics] " + label);
    const child = spawn(executable, argumentsList, {
      cwd: projectRoot,
      stdio: "inherit",
      windowsHide: true,
    });
    child.once("error", reject);
    child.once("exit", (code) => {
      if (code === 0) resolve();
      else reject(new Error(label + " exited with code " + code + "."));
    });
  });
}

async function requireFile(file) {
  try {
    if (!(await stat(file)).isFile()) throw new Error();
  } catch {
    throw new Error("Required forensic source is missing: " + file);
  }
}

async function sha256(file) {
  return createHash("sha256").update(await readFile(file)).digest("hex");
}

function stableHash(value) {
  return createHash("sha256").update(JSON.stringify(value)).digest("hex");
}

function projectPath(file) {
  return path.relative(projectRoot, file).split(path.sep).join("/");
}

function cleanSourceText(value) {
  return String(value ?? "").replaceAll(String.fromCharCode(0), "").trim();
}

await Promise.all([
  requireFile(globalBackup),
  requireFile(objectBackup),
  requireFile(powershellScript),
  ...recipe.source.catalogs.map((file) => requireFile(path.join(sourceRoot, file))),
]);
const temporary = await mkdtemp(path.join(os.tmpdir(), "healerman-fa-forensics-"));
const rawFile = path.join(temporary, "zone-102.raw.json");
try {
  await run(
    "powershell.exe",
    [
      "-NoProfile",
      "-ExecutionPolicy",
      "Bypass",
      "-File",
      powershellScript,
      "-ServerInstance",
      server,
      "-GlobalBackup",
      globalBackup,
      "-ObjectBackup",
      objectBackup,
      "-OutputFile",
      rawFile,
    ],
    "restore the two temporary databases, export Zone 102, and drop both databases",
  );
  const raw = JSON.parse((await readFile(rawFile, "utf8")).replace(/^\uFEFF/, ""));
  if (raw.rowCount !== recipe.expectedActiveRows || raw.rows.length !== recipe.expectedActiveRows) {
    throw new Error(
      "Expected " + recipe.expectedActiveRows + " active Zone 102 rows, found "
      + raw.rows.length + ".",
    );
  }
  const templates = new Map(recipe.templates.map((template) => [template.id, template]));
  const unmapped = [...new Set(
    raw.rows.filter((row) => !templates.has(row.templateId)).map((row) => row.templateId),
  )].sort((a, b) => a - b);
  if (unmapped.length) {
    const audit = unmapped.map((templateId) => {
      const matches = raw.rows.filter((row) => row.templateId === templateId);
      const first = matches[0];
      return {
        templateId,
        spawnCount: matches.length,
        name: first.localizedName || first.roleName || "",
        level: first.nativeLevel,
        sex: first.sex,
        roles: [...new Set(matches.map((row) => row.roleName).filter(Boolean))],
        autoPlots: [...new Set(matches.map((row) => row.autoPlot).filter(Boolean))],
      };
    });
    throw new Error("Unmapped Zone 102 templates:\n" + JSON.stringify(audit, null, 2));
  }
  const actors = new Map(recipe.actors.map((actor) => [actor.id, actor]));
  const spawnIds = new Set();
  const observedBossTemplates = new Set();
  const rows = raw.rows
    .map((row) => {
      const template = templates.get(row.templateId);
      if (!template) throw new Error("Unmapped Zone 102 template " + row.templateId + ".");
      if (spawnIds.has(row.spawnId)) throw new Error("Duplicate Zone 102 DBID " + row.spawnId + ".");
      spawnIds.add(row.spawnId);
      if (!Array.isArray(row.sourcePosition) || row.sourcePosition.some((value) => !Number.isFinite(value))) {
        throw new Error("Spawn " + row.spawnId + " has invalid source coordinates.");
      }
      if (row.sex === 3) observedBossTemplates.add(row.templateId);
      if (row.nativeLevel !== template.level) {
        throw new Error(
          "Template " + row.templateId + " level drift: expected " + template.level
          + ", database has " + row.nativeLevel + ".",
        );
      }
      const actor = template.actor ? actors.get(template.actor) : null;
      return {
        spawnId: row.spawnId,
        templateId: row.templateId,
        name: template.name,
        sourceName: cleanSourceText(row.localizedName)
          || cleanSourceText(row.roleName)
          || template.name,
        classification: template.classification,
        level: row.nativeLevel,
        sex: row.sex,
        modelPath: actor?.sourceModel ?? null,
        sourcePosition: row.sourcePosition.map(Number),
        direction: Number(row.direction),
        source: {
          roomId: row.roomId,
          roleName: cleanSourceText(row.roleName),
          autoPlot: cleanSourceText(row.autoPlot),
          plotClassName: cleanSourceText(row.plotClassName),
        },
      };
    })
    .sort((a, b) => a.spawnId - b.spawnId);

  const expectedBossTemplates = recipe.templates
    .filter((template) => template.classification === "boss")
    .map((template) => template.id)
    .sort((a, b) => a - b);
  const actualBossTemplates = [...observedBossTemplates].sort((a, b) => a - b);
  if (JSON.stringify(actualBossTemplates) !== JSON.stringify(expectedBossTemplates)) {
    throw new Error(
      "NPCObjectDB sex=3 classification drift. Expected "
      + expectedBossTemplates.join(", ") + "; found " + actualBossTemplates.join(", ") + ".",
    );
  }

  const sourceHashes = {
    backups: {
      [projectPath(globalBackup)]: await sha256(globalBackup),
      [projectPath(objectBackup)]: await sha256(objectBackup),
    },
    catalogs: Object.fromEntries(await Promise.all(recipe.source.catalogs.map(async (file) => {
      const absolute = path.join(sourceRoot, file);
      return [file.split(path.sep).join("/"), await sha256(absolute)];
    }))),
  };
  const content = {
    schemaVersion: 1,
    dungeonId: recipe.dungeonId,
    zoneId: recipe.zoneId,
    queryVersion: raw.queryVersion,
    rowCount: rows.length,
    sourceHashes,
    rows,
  };
  const snapshot = { ...content, contentSha256: stableHash(content) };
  await mkdir(path.dirname(snapshotFile), { recursive: true });
  await writeFile(snapshotFile, JSON.stringify(snapshot, null, 2) + "\n", "utf8");
  console.log(
    "\n[runewaker-forensics] wrote portable snapshot " + projectPath(snapshotFile)
    + " (" + rows.length + " rows, " + snapshot.contentSha256 + ").",
  );
  console.log("[runewaker-forensics] SQL Server is not used by the game or normal population build.");
} finally {
  await rm(temporary, { recursive: true, force: true });
}