// The Bisect and Trust views (spec §5.11, §5.12): small trees fed by

// `oxy bisect status --json`, `oxy policy show --json` and `oxy verify --json`.

import * as vscode from "vscode";

import { BisectStatus, PolicyInfo, VerifyInfo } from "./oxy";

import { Repository } from "./repository";

class Line extends vscode.TreeItem {

  constructor(label: string, opts: { description?: string; icon?: string; command?: vscode.Command; tooltip?: string; context?: string } = {}) {

    super(label, vscode.TreeItemCollapsibleState.None);

    this.description = opts.description;

    this.tooltip = opts.tooltip;

    this.command = opts.command;

    this.contextValue = opts.context;

    if (opts.icon) {

      this.iconPath = new vscode.ThemeIcon(opts.icon);

    }

  }

}

abstract class RepoTree implements vscode.TreeDataProvider<vscode.TreeItem> {

  private readonly emitter = new vscode.EventEmitter<void>();

  readonly onDidChangeTreeData = this.emitter.event;

  constructor(protected readonly repositories: () => Repository[]) {}

  refresh(): void {

    this.emitter.fire();

  }

  getTreeItem(element: vscode.TreeItem): vscode.TreeItem {

    return element;

  }

  async getChildren(element?: vscode.TreeItem): Promise<vscode.TreeItem[]> {

    const repos = this.repositories();

    if (!element) {

      if (repos.length === 1) {

        return this.items(repos[0]);

      }

      return repos.map((r) => {

        const item = new vscode.TreeItem(r.root.split("/").pop() ?? r.root, vscode.TreeItemCollapsibleState.Expanded);

        item.iconPath = new vscode.ThemeIcon("repo");

        (item as vscode.TreeItem & { repository?: Repository }).repository = r;

        return item;

      });

    }

    const repo = (element as vscode.TreeItem & { repository?: Repository }).repository;

    return repo ? this.items(repo) : [];

  }

  protected abstract items(repo: Repository): Promise<vscode.TreeItem[]>;

}

export class BisectProvider extends RepoTree {

  protected async items(repo: Repository): Promise<vscode.TreeItem[]> {

    let status: BisectStatus | null;

    try {

      status = await repo.oxy.bisectStatus(repo.root);

    } catch (e) {

      return [new Line(String(e), { icon: "warning" })];

    }

    const cmd = (title: string, command: string, args: unknown[] = []): vscode.Command => ({ title, command, arguments: [repo, ...args] });

    if (!status) {

      return [new Line("No bisect in progress", { icon: "search", description: "start one to find a regression", command: cmd("Start", "oxygen.bisectStart") })];

    }

    switch (status.state) {

      case "need-marks":

        return [

          new Line(`Marked ${status.good} good, ${status.bad} bad`, { icon: "search" }),

          new Line(status.good === 0 ? "Mark a known-good change or bookmark…" : "Mark a known-bad change or bookmark…", { icon: status.good === 0 ? "pass" : "error", command: cmd("Mark", status.good === 0 ? "oxygen.bisectGood" : "oxygen.bisectBad") }),

          new Line("Reset", { icon: "discard", command: cmd("Reset", "oxygen.bisectReset") }),

        ];

      case "testing":

        return [

          new Line(`Testing: ${status.remaining} candidates left`, { icon: "beaker", description: `about ${status.steps_left} more steps` }),

          new Line("This state is good", { icon: "pass", command: cmd("Good", "oxygen.bisectGood", [[]]) }),

          new Line("This state is bad", { icon: "error", command: cmd("Bad", "oxygen.bisectBad", [[]]) }),

          new Line("Skip: cannot test this state", { icon: "debug-step-over", command: cmd("Skip", "oxygen.bisectSkip") }),

          new Line("Run a command for every step…", { icon: "run-all", command: cmd("Run", "oxygen.bisectRun") }),

          new Line("Reset", { icon: "discard", command: cmd("Reset", "oxygen.bisectReset") }),

        ];

      case "found":

        return [

          new Line(`Found: ${status.culprit.slice(0, 12)}`, { icon: "bug", description: "the first change that makes the state bad", command: { title: "Show", command: "oxygen.showChange", arguments: [repo.root, status.culprit] } }),

          new Line("Reset: back to where you were", { icon: "discard", command: cmd("Reset", "oxygen.bisectReset") }),

        ];

      case "inconclusive":

        return [

          new Line(`Inconclusive: ${status.candidates.length} candidates could not be told apart`, { icon: "question" }),

          ...status.candidates.map((c) => new Line(c.slice(0, 12), { icon: "circle-outline", command: { title: "Show", command: "oxygen.showChange", arguments: [repo.root, c] } })),

          new Line("Reset", { icon: "discard", command: cmd("Reset", "oxygen.bisectReset") }),

        ];

    }

  }

}

export class TrustProvider extends RepoTree {

  protected async items(repo: Repository): Promise<vscode.TreeItem[]> {

    let policy: PolicyInfo | null;

    let verify: VerifyInfo[];

    try {

      [policy, verify] = await Promise.all([repo.oxy.policyShow(repo.root), repo.oxy.verify(repo.root)]);

    } catch (e) {

      return [new Line(String(e), { icon: "warning" })];

    }

    const items: vscode.TreeItem[] = [];

    if (!policy) {

      items.push(new Line("No trust policy: this repository is unverified", { icon: "unlock", description: "oxy policy init creates one", tooltip: "Without a policy every change and reference update is accepted." }));

    } else {

      const expires = new Date(policy.expires_ms).toLocaleDateString();

      items.push(new Line(`Policy serial ${policy.serial}`, { icon: policy.expired ? "error" : "shield", description: policy.expired ? `EXPIRED ${expires}` : `expires ${expires}` }));

      for (const r of policy.roots) {

        items.push(new Line(`Root: ${r.name || r.key.slice(0, 12)}`, { icon: "key", description: r.email, tooltip: r.key }));

      }

      items.push(new Line(`Root threshold ${policy.root_threshold}`, { icon: "law" }));

      for (const rule of policy.rules) {

        items.push(new Line(`Rule ${rule.pattern}`, { icon: "list-tree", description: `${rule.keys.map((k) => k.name || k.key.slice(0, 8)).join(", ")} · threshold ${rule.threshold} · ${rule.require}${rule.allow_conflicts ? "" : " · no conflicts"}` }));

      }

      for (const r of policy.revoked) {

        items.push(new Line(`Revoked: ${r.name || r.key.slice(0, 12)}`, { icon: "circle-slash" }));

      }

    }

    const counts = { signed: 0, sealed: 0, unsigned: 0, invalid: 0, revoked: 0 };

    for (const v of verify) {

      if (v.status in counts) {

        counts[v.status as keyof typeof counts] += 1;

      }

      if (v.revoked) {

        counts.revoked += 1;

      }

    }

    items.push(

      new Line(`${verify.length} changes verified`, {

        icon: counts.invalid > 0 ? "error" : "verified",

        description: `${counts.signed} signed, ${counts.sealed} sealed, ${counts.unsigned} unsigned${counts.invalid ? `, ${counts.invalid} INVALID` : ""}${counts.revoked ? `, ${counts.revoked} by revoked keys` : ""}`,

        command: { title: "Verify", command: "oxygen.verify", arguments: [repo] },

      }),

    );

    return items;

  }

}