import { Sys } from "../deps.ts";

export class ProjectNormalizer {
  constructor(readonly sys = Sys) {
  }

  async isDirectory(path: string): Promise<boolean> {
    try {
      return (await this.sys.stat(path)).isDirectory;
    } catch {
      return false;
    }
  }

  async isFile(path: string): Promise<boolean> {
    try {
      return (await this.sys.stat(path)).isFile;
    } catch {
      return false;
    }
  }

  async readContent(path: string): Promise<string> {
    try {
      return await this.sys.readTextFile(path);
    } catch {
      return "";
    }
  }

  async ensureDirectory(path: string) {
    if (!await this.isDirectory(path)) {
      await this.sys.mkdir(path, { recursive: true });
    }
  }

  async writeJsonFile(path: string, content: any) {
    await this.sys.writeTextFile(
      path,
      JSON.stringify(content),
    );
    await this.formatPath(path);
  }

  async writeLines(path: string, lines: string[]) {
    await this.sys.writeTextFile(
      path,
      lines.concat("").join("\n"),
    );
  }

  async run(...cmd: string[]): Promise<string> {
    const p = this.sys.run({ cmd, stdout: "piped", stderr: "piped" });
    const [status, stdout, stderr] = await Promise.all([
      p.status(),
      p.output(),
      p.stderrOutput(),
    ]);
    if (status.success) {
      return new TextDecoder().decode(stdout);
    } else {
      console.error(new TextDecoder().decode(stderr));
      throw new Error(`Command failed: ${cmd.join(" ")}`);
    }
  }

  async formatPath(path: string) {
    await this.run("./run", "fmt", "-q", path);
  }

  async updateRunScript() {
    await this.writeLines(
      "run",
      [
        `#!/bin/sh`,
        `# Simplified run tool for deno commands`,
        ``,
        `if test $# -eq 0`,
        `then`,
        `    echo "Usage: $0 [file or command]"`,
        `    exit 1`,
        `elif echo $1 | grep -q '.*\.ts'`,
        `then`,
        `    denocmd=run`,
        `    denoargs=$1`,
        `    shift`,
        `else`,
        `    denocmd=$1`,
        `    shift`,
        `fi`,
        ``,
        `denoargs="$(cat config/$denocmd.flags 2> /dev/null) $denoargs $@"`,
        `exec deno $denocmd $denoargs`,
      ],
    );
    await this.sys.chmod("run", 0o755);
  }

  async updateDenoDefs() {
    const defs = await this.run("./run", "types");
    await this.sys.writeTextFile("deno.d.ts", defs);
  }

  async updateEditorConfig() {
    await this.writeLines(
      ".editorconfig",
      [
        `root = true`,
        ``,
        `[*.{ts,json}]`,
        `charset = utf-8`,
        `end_of_line = lf`,
        `insert_final_newline = true`,
        `indent_style = space`,
        `indent_size = 2`,
        `trim_trailing_whitespace = true`,
      ],
    );
  }

  async updateTsConfig() {
    await this.writeJsonFile("tsconfig.json", {
      compilerOptions: {
        module: "esnext",
        target: "ESNext",
        strict: true,
        noImplicitReturns: true,
        noFallthroughCasesInSwitch: true,
        preserveConstEnums: true,
      },
    });
  }

  async updateVscodeConf() {
    await this.ensureDirectory(".vscode");
    const path = ".vscode/settings.json";
    const json_config = await this.readContent(path);
    const config = JSON.parse(json_config || "{}");
    if (!config["deno.enable"]) {
      config["deno.enable"] = true;
      await this.writeJsonFile(path, config);
    }

    await this.writeJsonFile(".vscode/tasks.json", {
      version: "2.0.0",
      tasks: [
        {
          label: "test",
          type: "shell",
          group: {
            kind: "test",
            isDefault: true,
          },
          command: "./run test",
        },
      ],
    });

    if (await this.isFile("cli.ts")) {
      await this.writeJsonFile(".vscode/launch.json", {
        version: "0.2.0",
        configurations: [
          {
            name: "Deno",
            type: "node",
            request: "launch",
            cwd: "\${workspaceFolder}",
            program: "cli.ts",
            console: "externalTerminal",
            attachSimplePort: 9229,
            runtimeExecutable: "deno",
            runtimeArgs: [
              "run",
              "--inspect",
            ].concat(
              (await this.readContent("config/run.flags"))
                .trim()
                .split(" ")
                .filter((part) => !!part),
            ),
          },
        ],
      });
    }
  }

  async updateGitIgnore() {
    await this.writeLines(
      ".gitignore",
      [
        `deno.d.ts`,
        `.vscode`,
        `.local`,
        `.output`,
        `web/*.js`,
      ],
    );
  }

  async updateGitHooks() {
    await this.writeLines(
      ".git/hooks/pre-commit",
      [
        `#!/bin/sh`,
        `set -e`,
        `./run fmt --check`,
        `./run test`,
      ],
    );
    await this.sys.chmod(".git/hooks/pre-commit", 0o755);
  }

  async updateReadme() {
    const project = this.sys.cwd().split("/").pop();
    let sections = "";
    if (await this.isDirectory("doc")) {
      const index = await this.readContent("doc/index");
      for (let section of index.split("\n")) {
        if (section?.trim()) {
          sections += "\n" +
            (await this.readContent(`doc/${section.trim()}.md`));
        }
      }
    }
    await this.writeLines(
      "README.md",
      [
        `# typescript/${project}`,
        `[![Build Status](https://thunderk.visualstudio.com/typescript/_apis/build/status/${project}?branchName=master)](https://dev.azure.com/thunderk/typescript/_build?pipelineNameFilter=${project})`,
        sections,
      ],
    );
    await this.formatPath("README.md");
  }

  async normalize() {
    if (!await this.isDirectory(".git")) {
      throw new Error("Not in a git repository");
    }

    await this.updateRunScript();
    await this.updateDenoDefs();
    await this.updateVscodeConf();
    await this.updateTsConfig();
    await this.updateEditorConfig();
    await this.updateGitIgnore();
    await this.updateGitHooks();
    await this.updateReadme();
  }
}

export async function normalize(sys = Sys) {
  const normalizer = new ProjectNormalizer(sys);
  await normalizer.normalize();
}