import JSON5 from "json5";
import type { Command } from "commander";

import { readConfigFileSnapshot, writeConfigFile } from "../config/config.js";
import { danger, info } from "../globals.js";
import { defaultRuntime } from "../runtime.js";
import { formatDocsLink } from "../terminal/links.js";
import { theme } from "../terminal/theme.js";

type PathSegment = string;

function isIndexSegment(raw: string): boolean {
  return /^[0-9]+$/.test(raw);
}

function parsePath(raw: string): PathSegment[] {
  const trimmed = raw.trim();
  if (!trimmed) return [];
  const parts: string[] = [];
  let current = "";
  let i = 0;
  while (i < trimmed.length) {
    const ch = trimmed[i];
    if (ch === "\\") {
      const next = trimmed[i + 1];
      if (next) current += next;
      i += 2;
      continue;
    }
    if (ch === ".") {
      if (current) parts.push(current);
      current = "";
      i += 1;
      continue;
    }
    if (ch === "[") {
      if (current) parts.push(current);
      current = "";
      const close = trimmed.indexOf("]", i);
      if (close === -1) throw new Error(`Invalid path (missing "]"): ${raw}`);
      const inside = trimmed.slice(i + 1, close).trim();
      if (!inside) throw new Error(`Invalid path (empty "[]"): ${raw}`);
      parts.push(inside);
      i = close + 1;
      continue;
    }
    current += ch;
    i += 1;
  }
  if (current) parts.push(current);
  return parts.map((part) => part.trim()).filter(Boolean);
}

function parseValue(raw: string, opts: { json?: boolean }): unknown {
  const trimmed = raw.trim();
  if (opts.json) {
    try {
      return JSON5.parse(trimmed);
    } catch (err) {
      throw new Error(`Failed to parse JSON5 value: ${String(err)}`);
    }
  }

  try {
    return JSON5.parse(trimmed);
  } catch {
    return raw;
  }
}

function getAtPath(root: unknown, path: PathSegment[]): { found: boolean; value?: unknown } {
  let current: unknown = root;
  for (const segment of path) {
    if (!current || typeof current !== "object") return { found: false };
    if (Array.isArray(current)) {
      if (!isIndexSegment(segment)) return { found: false };
      const index = Number.parseInt(segment, 10);
      if (!Number.isFinite(index) || index < 0 || index >= current.length) {
        return { found: false };
      }
      current = current[index];
      continue;
    }
    const record = current as Record<string, unknown>;
    if (!(segment in record)) return { found: false };
    current = record[segment];
  }
  return { found: true, value: current };
}

function setAtPath(root: Record<string, unknown>, path: PathSegment[], value: unknown): void {
  let current: unknown = root;
  for (let i = 0; i < path.length - 1; i += 1) {
    const segment = path[i];
    const next = path[i + 1];
    const nextIsIndex = Boolean(next && isIndexSegment(next));
    if (Array.isArray(current)) {
      if (!isIndexSegment(segment)) {
        throw new Error(`Expected numeric index for array segment "${segment}"`);
      }
      const index = Number.parseInt(segment, 10);
      const existing = current[index];
      if (!existing || typeof existing !== "object") {
        current[index] = nextIsIndex ? [] : {};
      }
      current = current[index];
      continue;
    }
    if (!current || typeof current !== "object") {
      throw new Error(`Cannot traverse into "${segment}" (not an object)`);
    }
    const record = current as Record<string, unknown>;
    const existing = record[segment];
    if (!existing || typeof existing !== "object") {
      record[segment] = nextIsIndex ? [] : {};
    }
    current = record[segment];
  }

  const last = path[path.length - 1];
  if (Array.isArray(current)) {
    if (!isIndexSegment(last)) {
      throw new Error(`Expected numeric index for array segment "${last}"`);
    }
    const index = Number.parseInt(last, 10);
    current[index] = value;
    return;
  }
  if (!current || typeof current !== "object") {
    throw new Error(`Cannot set "${last}" (parent is not an object)`);
  }
  (current as Record<string, unknown>)[last] = value;
}

function unsetAtPath(root: Record<string, unknown>, path: PathSegment[]): boolean {
  let current: unknown = root;
  for (let i = 0; i < path.length - 1; i += 1) {
    const segment = path[i];
    if (!current || typeof current !== "object") return false;
    if (Array.isArray(current)) {
      if (!isIndexSegment(segment)) return false;
      const index = Number.parseInt(segment, 10);
      if (!Number.isFinite(index) || index < 0 || index >= current.length) return false;
      current = current[index];
      continue;
    }
    const record = current as Record<string, unknown>;
    if (!(segment in record)) return false;
    current = record[segment];
  }

  const last = path[path.length - 1];
  if (Array.isArray(current)) {
    if (!isIndexSegment(last)) return false;
    const index = Number.parseInt(last, 10);
    if (!Number.isFinite(index) || index < 0 || index >= current.length) return false;
    current.splice(index, 1);
    return true;
  }
  if (!current || typeof current !== "object") return false;
  const record = current as Record<string, unknown>;
  if (!(last in record)) return false;
  delete record[last];
  return true;
}

async function loadValidConfig() {
  const snapshot = await readConfigFileSnapshot();
  if (snapshot.valid) return snapshot;
  defaultRuntime.error(`Config invalid at ${snapshot.path}.`);
  for (const issue of snapshot.issues) {
    defaultRuntime.error(`- ${issue.path || "<root>"}: ${issue.message}`);
  }
  defaultRuntime.error("Run `clawdbot doctor` to repair, then retry.");
  defaultRuntime.exit(1);
  return snapshot;
}

export function registerConfigCli(program: Command) {
  const cmd = program
    .command("config")
    .description("Config helpers (get/set/unset). Run without subcommand for the wizard.")
    .addHelpText(
      "after",
      () =>
        `\n${theme.muted("Docs:")} ${formatDocsLink("/cli/config", "docs.clawd.bot/cli/config")}\n`,
    )
    .option(
      "--section <section>",
      "Configure wizard sections (repeatable). Use with no subcommand.",
      (value: string, previous: string[]) => [...previous, value],
      [] as string[],
    )
    .action(async (opts) => {
      const { CONFIGURE_WIZARD_SECTIONS, configureCommand, configureCommandWithSections } =
        await import("../commands/configure.js");
      const sections: string[] = Array.isArray(opts.section)
        ? opts.section
            .map((value: unknown) => (typeof value === "string" ? value.trim() : ""))
            .filter(Boolean)
        : [];
      if (sections.length === 0) {
        await configureCommand(defaultRuntime);
        return;
      }

      const invalid = sections.filter((s) => !CONFIGURE_WIZARD_SECTIONS.includes(s as never));
      if (invalid.length > 0) {
        defaultRuntime.error(
          `Invalid --section: ${invalid.join(", ")}. Expected one of: ${CONFIGURE_WIZARD_SECTIONS.join(", ")}.`,
        );
        defaultRuntime.exit(1);
        return;
      }

      await configureCommandWithSections(sections as never, defaultRuntime);
    });

  cmd
    .command("get")
    .description("Get a config value by dot path")
    .argument("<path>", "Config path (dot or bracket notation)")
    .option("--json", "Output JSON", false)
    .action(async (path: string, opts) => {
      try {
        const parsedPath = parsePath(path);
        if (parsedPath.length === 0) {
          throw new Error("Path is empty.");
        }
        const snapshot = await loadValidConfig();
        const res = getAtPath(snapshot.config, parsedPath);
        if (!res.found) {
          defaultRuntime.error(danger(`Config path not found: ${path}`));
          defaultRuntime.exit(1);
          return;
        }
        if (opts.json) {
          defaultRuntime.log(JSON.stringify(res.value ?? null, null, 2));
          return;
        }
        if (
          typeof res.value === "string" ||
          typeof res.value === "number" ||
          typeof res.value === "boolean"
        ) {
          defaultRuntime.log(String(res.value));
          return;
        }
        defaultRuntime.log(JSON.stringify(res.value ?? null, null, 2));
      } catch (err) {
        defaultRuntime.error(danger(String(err)));
        defaultRuntime.exit(1);
      }
    });

  cmd
    .command("set")
    .description("Set a config value by dot path")
    .argument("<path>", "Config path (dot or bracket notation)")
    .argument("<value>", "Value (JSON5 or raw string)")
    .option("--json", "Parse value as JSON5 (required)", false)
    .action(async (path: string, value: string, opts) => {
      try {
        const parsedPath = parsePath(path);
        if (parsedPath.length === 0) throw new Error("Path is empty.");
        const parsedValue = parseValue(value, opts);
        const snapshot = await loadValidConfig();
        const next = snapshot.config as Record<string, unknown>;
        setAtPath(next, parsedPath, parsedValue);
        await writeConfigFile(next);
        defaultRuntime.log(info(`Updated ${path}. Restart the gateway to apply.`));
      } catch (err) {
        defaultRuntime.error(danger(String(err)));
        defaultRuntime.exit(1);
      }
    });

  cmd
    .command("unset")
    .description("Remove a config value by dot path")
    .argument("<path>", "Config path (dot or bracket notation)")
    .action(async (path: string) => {
      try {
        const parsedPath = parsePath(path);
        if (parsedPath.length === 0) throw new Error("Path is empty.");
        const snapshot = await loadValidConfig();
        const next = snapshot.config as Record<string, unknown>;
        const removed = unsetAtPath(next, parsedPath);
        if (!removed) {
          defaultRuntime.error(danger(`Config path not found: ${path}`));
          defaultRuntime.exit(1);
          return;
        }
        await writeConfigFile(next);
        defaultRuntime.log(info(`Removed ${path}. Restart the gateway to apply.`));
      } catch (err) {
        defaultRuntime.error(danger(String(err)));
        defaultRuntime.exit(1);
      }
    });
}