From 723ff201f62a9c232c2afdf2b8e27ce61c7ce164 Mon Sep 17 00:00:00 2001
From: Munif Tanjim <muniftanjim@gmail.com>
Date: Tue, 26 May 2020 19:17:41 +0600
Subject: [PATCH] add completion generation for zsh (#137)

---
 src/commands/completion.command.ts | 135 +++++++++++++++++++++++++++++
 src/program.ts                     |  22 +++++
 2 files changed, 157 insertions(+)
 create mode 100644 src/commands/completion.command.ts

diff --git a/src/commands/completion.command.ts b/src/commands/completion.command.ts
new file mode 100644
index 0000000000..289377c608
--- /dev/null
+++ b/src/commands/completion.command.ts
@@ -0,0 +1,135 @@
+import * as program from "commander";
+import { Response } from "jslib/cli/models/response";
+import { MessageResponse } from "jslib/cli/models/response/messageResponse";
+
+type Option = {
+    long: string;
+    short: string;
+    description: string;
+};
+
+type Command = {
+    commands?: Command[];
+    options?: Option[];
+    _name: string;
+    _description: string;
+};
+
+const zshCompletion = (rootName: string, rootCommand: Command) => {
+    const renderCommandBlock = (name: string, command: Command): string => {
+        const { commands = [], options = [] } = command;
+        const hasOptions = options.length > 0;
+        const hasCommands = commands.length > 0;
+
+        const _arguments = options
+            .map(({ long, short, description }) => {
+                const aliases = [short, long].filter(Boolean);
+
+                const OPTS = aliases.join(",");
+
+                const DESCRIPTION = `[${description.replace("'", `'"'"'`)}]`;
+
+                return aliases.length > 1
+                    ? `'(${aliases.join(" ")})'{${OPTS}}'${DESCRIPTION}'`
+                    : `'${OPTS}${DESCRIPTION}'`;
+            })
+            .concat(
+                `'(-h --help)'{-h,--help}'[output usage information]'`,
+                hasCommands ? '"1: :->cmnds"' : null,
+                '"*::arg:->args"'
+            )
+            .filter(Boolean);
+
+        const commandBlockFunctionParts = [];
+
+        if (hasCommands) {
+            commandBlockFunctionParts.push("local -a commands");
+        }
+
+        if (hasOptions) {
+            commandBlockFunctionParts.push(
+                `_arguments -C \\\n    ${_arguments.join(` \\\n    `)}`
+            );
+        }
+
+        if (hasCommands) {
+            commandBlockFunctionParts.push(
+                `case $state in
+    cmnds)
+      commands=(
+        ${commands
+            .map(({ _name, _description }) => `"${_name}:${_description}"`)
+            .join("\n        ")}
+      )
+      _describe "command" commands
+      ;;
+  esac
+
+  case "$words[1]" in
+    ${commands
+        .map(({ _name }) =>
+            [`${_name})`, `_${name}_${_name}`, ";;"].join("\n      ")
+        )
+        .join("\n    ")}
+  esac`
+            );
+        }
+
+        const commandBlocParts = [
+            `function _${name} {\n  ${commandBlockFunctionParts.join(
+                "\n\n  "
+            )}\n}`,
+        ];
+
+        if (hasCommands) {
+            commandBlocParts.push(
+                commands
+                    .map((command) =>
+                        renderCommandBlock(`${name}_${command._name}`, command)
+                    )
+                    .join("\n\n")
+            );
+        }
+
+        return commandBlocParts.join("\n\n");
+    };
+
+    const render = () => {
+        return [
+            `#compdef _${rootName} ${rootName}`,
+            "",
+            renderCommandBlock(rootName, rootCommand),
+        ].join("\n");
+    };
+
+    return {
+        render,
+    };
+};
+
+const validShells = ["zsh"];
+
+export class CompletionCommand {
+    constructor() {}
+
+    async run(cmd: program.Command) {
+        const shell: typeof validShells[number] = cmd.shell;
+
+        if (!shell) {
+            return Response.badRequest("`shell` was not provided!");
+        }
+
+        if (!validShells.includes(shell)) {
+            return Response.badRequest(`Unsupported shell!`);
+        }
+
+        let content = "";
+
+        if (shell === "zsh") {
+            content = zshCompletion("bw", cmd.parent).render();
+        }
+
+        const res = new MessageResponse(content, null);
+        return Response.success(res);
+    }
+}
diff --git a/src/program.ts b/src/program.ts
index 6f8a40c557..beb1d7791b 100644
--- a/src/program.ts
+++ b/src/program.ts
@@ -21,6 +21,8 @@ import { ShareCommand } from './commands/share.command';
 import { SyncCommand } from './commands/sync.command';
 import { UnlockCommand } from './commands/unlock.command';
 
+import { CompletionCommand } from './commands/completion.command';
+
 import { LogoutCommand } from 'jslib/cli/commands/logout.command';
 import { UpdateCommand } from 'jslib/cli/commands/update.command';
 
@@ -660,6 +662,26 @@ export class Program extends BaseProgram {
                 this.processResponse(response);
             });
 
+        program
+            .command('completion')
+            .description('Generate shell completions.')
+            .option('--shell <shell>', 'Shell to generate completions for.')
+            .on('--help', () => {
+                writeLn('\n  Notes:');
+                writeLn('');
+                writeLn('    Valid shells are `zsh`.')
+                writeLn('');
+                writeLn('  Examples:');
+                writeLn('');
+                writeLn('    bw completion --shell zsh');
+                writeLn('', true);
+            })
+            .action(async (cmd: program.Command) => {
+                const command = new CompletionCommand();
+                const response = await command.run(cmd);
+                this.processResponse(response);
+            })
+
         program
             .parse(process.argv);