// Pure spawn-form model, kept when spawnForm.ts's imperative DOM form was
// deleted (#253): the value/seed shapes, the request builder, and the preset
// fallback. SpawnForm.tsx and useFastForward.ts render from these.

import { splitCommand } from "../../toolIcon.js";
import type { CreateSessionRequest, SpawnPreset } from "../../types.js";

export const STRUCTURED_VIEW_TOOLS = new Set(["claude", "codex"]);

export function supportsStructuredView(command: string): boolean {
  const tool = splitCommand(command).tool;
  return tool !== null && STRUCTURED_VIEW_TOOLS.has(tool);
}

/** Where a worktree's branch comes from: freshly created (default) or picked
 * from the repository's existing branches (#61). */
export type WorktreeBranchMode = "new" | "existing";

/** Seed values for the spawn form — used by "Spawn similar" to open the modal
 * with the same cwd, command, and name as an existing session, and by the
 * fast-forward fallback to pre-fill whatever it did resolve. */
export interface SpawnFormSeed {
  command?: string;
  cwd?: string;
  name?: string;
  worktreeEnabled?: boolean;
  worktreeBranch?: string;
  /** Whether the operator typed the branch themselves, rather than it having
   *  been auto-synced from the session name. Carried separately because the
   *  value alone cannot distinguish the two. */
  worktreeBranchEdited?: boolean;
  worktreeBranchMode?: WorktreeBranchMode;
  cwdRawVisible?: boolean;
}

/** The form's current values, reported on every change. */
export interface SpawnFormValues {
  command: string;
  cwd: string;
  name: string;
  structuredView: boolean;
  autoApprove: boolean;
  worktreeEnabled: boolean;
  worktreeBranch: string;
  worktreeBranchEdited: boolean;
  /** "new" creates the branch; "existing" checks out a picked one (#61). */
  worktreeBranchMode: WorktreeBranchMode;
  /** Whether the cwd lives in the raw text input (vs a picked recent row). */
  cwdRawVisible?: boolean;
}

export function buildSpawnRequest(
  values: SpawnFormValues,
  baseRepo: string | null,
): { req: CreateSessionRequest } | { error: string } {
  if (!values.cwd) return { error: "Pick a working directory." };
  if (!values.command) return { error: "Pick a command (or fill the custom command)." };

  const metadata: Record<string, unknown> = {};
  const name = values.name.trim();
  if (name) metadata.name = name;

  const req: CreateSessionRequest = {
    cwd: values.cwd,
    command: values.command,
    metadata,
  };

  if (values.structuredView && supportsStructuredView(values.command)) {
    req.view = "Structured";
  }

  if (values.autoApprove) {
    req.auto_approve = true;
  }

  if (values.worktreeEnabled) {
    const mode = values.worktreeBranchMode ?? "new";
    const branch = values.worktreeBranch.trim();
    if (!baseRepo) return { error: "Worktree needs a directory inside a git repository." };
    if (!branch) {
      return { error: mode === "existing" ? "Pick an existing branch." : "Worktree requires a branch name." };
    }
    req.worktree = {
      base_repo: baseRepo,
      branch,
      // Existing-mode picks must check out as-is; the daemon creates
      // anything else with `worktree add -b` (#56/#61).
      create_branch: mode !== "existing",
    };
  }

  return { req };
}

/** Built-ins used when the daemon's `/api/info` presets can't be fetched
 * (older daemon, transient error). Mirrors `maestro_config::builtin_presets`.
 * Exported for the fast-forward spawn's preset fallback (#67). */
export const FALLBACK_PRESETS: SpawnPreset[] = [
  { id: "claude", label: "Claude", command: "claude" },
  { id: "opencode", label: "opencode", command: "opencode" },
  { id: "zsh", label: "Shell", command: "zsh" },
  { id: "custom", label: "Custom…", command: "" },
];