import type { DiffOptions } from "@bindings/cob/DiffOptions";
import type { Diff } from "@bindings/diff/Diff";
import type { Stats } from "@bindings/diff/Stats";
import type { Commit } from "@bindings/repo/Commit";
import type { Job } from "@bindings/repo/Job";
import type { RepoSummary } from "@bindings/repo/RepoSummary";

import * as tauri from "@tauri-apps/api/core";

import { cached } from "@app/lib/cached";

export async function invoke<T = null>(
  cmd: string,
  args?: tauri.InvokeArgs,
  options?: tauri.InvokeOptions,
): Promise<T> {
  if (import.meta.env.DEV) {
    const start = performance.now();
    try {
      return await withTestBackend<T>(tauri.invoke, cmd, args, options);
    } finally {
      const ms = Math.round(performance.now() - start);

      console.debug(`[invoke] ${cmd} ${ms}ms`);
    }
  }
  return withTestBackend<T>(tauri.invoke, cmd, args, options);
}

/**
 * Invoking a Tauri command returned an error with the given message
 */
class InvokeError extends Error {
  name = "InvokeError";
  code: string;

  constructor(message: string, code = "Unknown Error") {
    super(message);
    this.code = code;
    Error.captureStackTrace?.(this, InvokeError);
  }
}

async function withTestBackend<T>(
  fn: (
    cmd: string,
    args?: tauri.InvokeArgs,
    options?: tauri.InvokeOptions,
  ) => Promise<T>,
  cmd: string,
  args?: tauri.InvokeArgs,
  options?: tauri.InvokeOptions,
) {
  if (window.__TAURI_INTERNALS__) {
    // eslint-disable-next-line @typescript-eslint/no-explicit-any
    return fn(cmd, args, options).catch((error: any) => {
      if (typeof error === "object" && error !== null && "message" in error) {
        throw new InvokeError(String(error.message), String(error.code));
      } else {
        throw new InvokeError(`Invalid error object: ${error}`);
      }
    });
  } else {
    return fetch(
      `http://127.0.0.1:${import.meta.env.VITE_TEST_HTTP_API_PORT ?? 8081}/${cmd}`,
      {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify(args),
      },
    ).then(async response => {
      if (response.status === 404) {
        console.log("Got a 404 response:", response);
        return null;
      }
      const json = await response.json();
      if (!response.ok) {
        if (typeof json === "object" && json !== null && "message" in json) {
          throw new InvokeError(String(json.message), String(json.code));
        } else {
          throw new InvokeError(`Invalid error object: ${json}`);
        }
      }

      return json;
    });
  }
}

async function getDiff(rid: string, options: DiffOptions): Promise<Diff> {
  return withTestBackend(tauri.invoke, "get_diff", {
    rid,
    options,
  });
}

export const cachedGetDiff = cached(
  getDiff,
  (...[rid, options]) =>
    `get_diff:${rid}:${JSON.stringify(options, Object.keys(options).sort())}`,
  { max: 10_000 },
);

async function listCommits(
  rid: string,
  base: string,
  head: string,
): Promise<Commit[]> {
  return withTestBackend(tauri.invoke, "list_commits", { rid, base, head });
}

export const cachedListCommits = cached(
  listCommits,
  (...[rid, base, head]) => `list_commits:${rid}:${base}:${head}`,
  { max: 5_000 },
);

async function repoCommitCount(rid: string, head: string): Promise<number> {
  return withTestBackend(tauri.invoke, "repo_commit_count", { rid, head });
}

export const cachedRepoCommitCount = cached(
  repoCommitCount,
  (...[rid, head]) => `repo_commit_count:${rid}:${head}`,
  { max: 5_000 },
);

async function listJobs(rid: string, sha: string): Promise<Job[]> {
  return withTestBackend(tauri.invoke, "list_jobs", { rid, sha });
}

// Listing jobs scans every job COB in the repo, so it is slow (hundreds of ms
// to seconds). It is re-requested on every JobCob mount; caching by (rid, sha)
// collapses concurrent identical calls into one in-flight request and reuses
// the result across navigations. A short TTL keeps CI status reasonably fresh.
export const cachedListJobs = cached(
  listJobs,
  (...[rid, sha]) => `list_jobs:${rid}:${sha}`,
  { max: 200, ttl: 30_000 },
);

async function diffStats(
  rid: string,
  base: string,
  head: string,
): Promise<Stats> {
  return withTestBackend(tauri.invoke, "diff_stats", {
    rid,
    base,
    head,
  });
}

export const cachedDiffStats = cached(
  diffStats,
  (...[rid, base, head]) => `diff_stats:${rid}:${base}:${head}`,
  { max: 10_000 },
);

// Patch text is generated by libgit2 on the backend (byte-accurate `git diff`
// output) instead of being reconstructed from the structured diff model.
// Callers pass the same `unified` value the rendered diff used so the text
// matches what's on screen; `base` unset diffs `head` against its first
// parent; `path` limits output to a single file.
export async function getDiffText(
  rid: string,
  base: string | undefined,
  head: string,
  unified: number,
  path?: string,
): Promise<string> {
  return withTestBackend(tauri.invoke, "get_diff_text", {
    rid,
    base,
    head,
    unified,
    path,
  });
}

// Commits and patch revisions are immutable, so the same (base, head, unified,
// path) always yields the same patch text — safe to cache. Capped since a
// commit's full patch can be sizeable.
export const cachedGetDiffText = cached(
  getDiffText,
  (...[rid, base, head, unified, path]) =>
    `get_diff_text:${rid}:${base}:${head}:${unified}:${path}`,
  { max: 100 },
);

async function getCommitDiff(
  rid: string,
  sha: string,
  unified = 3,
  highlight = true,
): Promise<Diff> {
  return withTestBackend(tauri.invoke, "get_commit_diff", {
    rid,
    sha,
    unified,
    highlight,
  });
}

// Commits are immutable, so SHA is a perfect cache key. Cap entries since
// each highlighted Diff can be sizeable.
export const cachedGetCommitDiff = cached(
  getCommitDiff,
  (...[rid, sha, unified, highlight]) =>
    `get_commit_diff:${rid}:${sha}:${unified}:${highlight}`,
  { max: 100 },
);

/**
 * Enumerating repos loads and verifies the identity doc of every repo in
 * storage, which takes ~100ms with many repos. The list rarely changes, so it
 * is cached with a short TTL; mutations that change it (adding, seeding,
 * unseeding) go through invalidateReposSummary().
 */
export const cachedListReposSummary = cached(
  () => invoke<RepoSummary[]>("list_repos_summary"),
  () => "list_repos_summary",
  { max: 1, ttl: 30_000 },
);

export function invalidateReposSummary(): void {
  cachedListReposSummary.clear();
}

export async function writeToClipboard(
  text: string,
  opts?: {
    label?: string;
  },
) {
  if (window.__TAURI_INTERNALS__) {
    await tauri.invoke("plugin:clipboard-manager|write_text", {
      label: opts?.label,
      text,
    });
  } else {
    await navigator.clipboard.writeText(text);
  }
}

export async function saveToDisk(fileName: string, text: string) {
  if (window.__TAURI_INTERNALS__) {
    // The backend opens the native save dialog and writes the file.
    await tauri.invoke("save_diff_to_disk", { name: fileName, content: text });
  } else {
    // No native dialog outside Tauri (test/http mode): trigger a download.
    const url = URL.createObjectURL(new Blob([text], { type: "text/plain" }));
    const anchor = document.createElement("a");
    anchor.href = url;
    anchor.download = fileName;
    anchor.click();
    URL.revokeObjectURL(url);
  }
}

export { InvokeError };