import { Octokit } from "@octokit/rest";
import { KoreFileAdaptor } from "./KoreFileAdaptor";
import { encode as arrayBufferToBase64 } from "base64-arraybuffer";
// https://github.com/octokit/rest.js/issues/1971
import type { components } from "@octokit/openapi-types";
import { fromBase64 } from "js-base64";

type GetRepoContentResponseDataFile = components["schemas"]["content-file"];

const debug = require("debug")("korefile");
const GITHUB_API_TOKEN = typeof process === "object" && process.env.GITHUB_API_TOKEN;

export interface GitCommitPushOptions {
    owner: string;
    repo: string;
    files: {
        path: string;
        content: string | ArrayBuffer;
    }[];
    ref: string;
    forceUpdate?: boolean;
    commitMessage?: string;
    token?: string; // or process.env.GITHUB_API_TOKEN
}

const getReferenceCommit = function (octokit: Octokit, options: Pick<GitCommitPushOptions, "owner" | "repo" | "ref">) {
    return octokit.git
        .getRef({
            owner: options.owner,
            repo: options.repo,
            ref: options.ref
        })
        .then((res) => {
            debug("getReferenceCommit Response: %O", res);
            return { referenceCommitSha: res.data.object.sha };
        });
};

const createTree = function (
    octokit: Octokit,
    options: Pick<GitCommitPushOptions, "owner" | "repo" | "files">,
    data: { referenceCommitSha: string }
) {
    const promises = options.files.map((file) => {
        if (typeof file.content === "string") {
            return octokit.git
                .createBlob({
                    owner: options.owner,
                    repo: options.repo,
                    content: file.content,
                    encoding: "utf-8"
                })
                .then((blob: any) => {
                    debug("createBlob:text");
                    return {
                        sha: blob.data.sha,
                        path: file.path,
                        mode: "100644",
                        type: "blob"
                    } as const;
                });
        } else if (ArrayBuffer.isView(file.content)) {
            return octokit.git
                .createBlob({
                    owner: options.owner,
                    repo: options.repo,
                    content: arrayBufferToBase64(file.content),
                    encoding: "base64"
                })
                .then((blob: any) => {
                    debug("createBlob:buffer");
                    return {
                        sha: blob.data.sha,
                        path: file.path,
                        mode: "100644",
                        type: "blob"
                    } as const;
                });
        }
        throw new Error(`This file can not handled: ${file}`);
    });
    return Promise.all(promises).then((files) => {
        debug("files: %O", files);
        return octokit.git
            .createTree({
                owner: options.owner,
                repo: options.repo,
                tree: files,
                base_tree: data.referenceCommitSha
            })
            .then((res) => {
                debug("createCommit Response: %O", res);
                return {
                    ...data,
                    newTreeSha: res.data.sha
                };
            });
    });
};

const createCommit = function (
    octokit: Octokit,
    options: Pick<GitCommitPushOptions, "owner" | "repo" | "commitMessage">,
    data: any
) {
    return octokit.git
        .createCommit({
            owner: options.owner,
            repo: options.repo,
            message: options.commitMessage || "commit",
            tree: data.newTreeSha,
            parents: [data.referenceCommitSha]
        })
        .then((res) => {
            debug("createTree Response: %O", res);
            return { ...data, newCommitSha: res.data.sha };
        });
};

const updateReference = function (github: Octokit, options: GitCommitPushOptions, data: any) {
    return github.git
        .updateRef({
            owner: options.owner,
            repo: options.repo,
            ref: options.ref,
            sha: data.newCommitSha,
            force: options.forceUpdate
        })
        .then((res) => {
            debug("updateReference Response: %O", res);
        });
};

export const getContent = (
    github: Octokit,
    {
        owner,
        repo,
        path,
        ref
    }: {
        owner: string;
        repo: string;
        path: string;
        ref: string;
    }
) => {
    return github.repos
        .getContent({
            owner,
            repo,
            path,
            ref
        })
        .then((res) => {
            const data = res.data as GetRepoContentResponseDataFile;
            if (Array.isArray(data)) {
                throw new Error(`folder does not support`);
            }
            debug("getContent Response: %O", res);
            if (data.type !== "file") {
                return Promise.reject(new Error("This is not file:" + path));
            }
            if (data.encoding === "base64") {
                // TODO: support binary
                return Promise.resolve(fromBase64(data.content));
            }
            throw new Error("Unknown file type" + data.type + ":" + data.encoding);
        });
};

export const deleteFile = async (
    octokit: Octokit,
    {
        owner,
        repo,
        path,
        ref,
        commitMessage
    }: {
        owner: string;
        repo: string;
        path: string;
        ref: string;
        commitMessage: string;
    }
) => {
    const response = await octokit.repos.getContent({
        owner,
        repo,
        path,
        ref
    });
    const { data } = response;
    debug("deleteFile:getContents Response: %O", data);
    if (Array.isArray(data)) {
        throw new Error(`folder does not support`);
    }
    return octokit.repos
        .deleteFile({
            owner,
            repo,
            path,
            branch: ref.replace(/^refs\//, "").replace(/^heads\//, ""),
            sha: data.sha,
            message: commitMessage
        })
        .then((res) => {
            debug("deleteFile:deleteFile Response: %O", res);
        });
};

export interface GitHubAdaptorOptions {
    host?: string;
    owner: string;
    repo: string;
    ref: string;
    commitMessage?: {
        write?: (filePath: string) => string;
        delete?: (filePath: string) => string;
    };
    forceUpdate?: boolean;
    token?: string; // or process.env.GITHUB_API_TOKEN
}

export const createGitHubAdaptor = (options: GitHubAdaptorOptions): KoreFileAdaptor => {
    const token = options.token || GITHUB_API_TOKEN;
    if (!token) {
        throw new Error(`token is not defined`);
    }
    const octKit = new Octokit({
        auth: token,
        type: "oauth",
        userAgent: "korefile"
    });
    const filledOptions = {
        owner: options.owner,
        repo: options.repo,
        ref: options.ref,
        forceUpdate: options.forceUpdate || false
    };
    return {
        readFile(filePath: string): Promise<string> {
            return getContent(octKit, {
                repo: filledOptions.repo,
                owner: filledOptions.owner,
                path: filePath,
                ref: filledOptions.ref
            });
        },
        writeFile(filePath: string, content: string | ArrayBuffer): Promise<void> {
            const withFileOption = {
                ...filledOptions,
                files: [
                    {
                        path: filePath,
                        content: content
                    }
                ]
            };
            const commitMessage =
                options.commitMessage && typeof options.commitMessage.write === "function"
                    ? options.commitMessage.write(filePath)
                    : `Update ${filePath}`;
            return getReferenceCommit(octKit, filledOptions)
                .then((data) => createTree(octKit, withFileOption, data))
                .then((data) =>
                    createCommit(
                        octKit,
                        {
                            ...filledOptions,
                            commitMessage
                        },
                        data
                    )
                )
                .then((data) => updateReference(octKit, withFileOption, data));
        },
        writeFiles(files: { path: string; content: string | ArrayBuffer }[]): Promise<void> {
            const withFileOption = {
                ...filledOptions,
                files: files
            };
            const commitMessage = `Update files`;
            return getReferenceCommit(octKit, filledOptions)
                .then((data) => createTree(octKit, withFileOption, data))
                .then((data) =>
                    createCommit(
                        octKit,
                        {
                            ...filledOptions,
                            commitMessage
                        },
                        data
                    )
                )
                .then((data) => updateReference(octKit, withFileOption, data));
        },
        deleteFile(filePath: string): Promise<void> {
            const commitMessage =
                options.commitMessage && typeof options.commitMessage.delete === "function"
                    ? options.commitMessage.delete(filePath)
                    : `Delete ${filePath}`;
            return deleteFile(octKit, {
                ...filledOptions,
                path: filePath,
                commitMessage: commitMessage
            });
        }
    };
};