/**
 * Tool render-intent vocabulary: the provider-neutral types a tool declares via
 * `ToolDefinition.presentCall`/`ToolDefinition.presentResult` to say
 * how ONE of its calls renders in a UI (an editor's tool-call card, a CLI log
 * line). A UI bridge switches on the `card` tag to map each intent to its own
 * wire shape, so a UI never special-cases tool names.
 *
 * This is the UI-facing surface of `dsh-tools`, kept separate from the registry
 * and execution core in `index.ts`: this module owns ONLY presentation
 * vocabulary and references none of the execution types, so the dependency runs
 * one way (`index.ts` imports these views for the `ToolDefinition` method
 * signatures). The opaque `meta` presentation channel is execution plumbing and
 * lives with the registry in `index.ts`, not here.
 *
 * See the render-intent-union RFC
 * (docs/rfc/implemented/architecture/2026-07-02-tool-render-intent-union.md).
 *
 * @module @deepseek-ai/dsh-tools/src/presentation
 */

import type { ContentBlock } from '@deepseek-ai/dsh-llm'

/**
 * Category of a tool call, used by a UI to pick an icon / treatment. A neutral
 * vocabulary owned here (NOT an ACP type) so tools describe themselves without
 * depending on any client protocol; a UI bridge maps it to its own enum. The
 * member set mirrors the common ACP `ToolKind` values; `other` is the default.
 */
export type ToolCallKind = 'read' | 'edit' | 'delete' | 'move' | 'search' | 'execute' | 'fetch' | 'other'

/**
 * A file location a tool reads or modifies, so a capable UI can "follow along" —
 * highlight or jump to the file (and line) as the tool runs. Provider-neutral;
 * a UI bridge maps it to its own affordance (the ACP bridge forwards it as
 * `tool_call.locations`). `path` is what the tool operated on (the model-facing
 * path); `line` is an optional 1-based line to focus (e.g. a read's offset).
 */
export interface FileLocation {
  path: string
  line?: number
}

/**
 * A single-file change a tool is about to make, for a UI that renders inline
 * diffs (an editor's diff card). Provider-neutral; the ACP bridge forwards it as
 * a `{ type: 'diff' }` tool-call content block. `oldText` is `null` for a
 * new-file create (nothing to diff against); an overwrite also uses `null`,
 * because a call-time presenter has no access to the file's prior content.
 */
export interface FileDiff {
  path: string
  /** Prior content, or `null` for a new file / an overwrite (no prior content available at call time). */
  oldText: string | null
  /** Content after the change. */
  newText: string
}

/**
 * How a tool wants ONE of its calls shown in a UI (an editor's tool-call card, a
 * CLI log line) BEFORE the result is known — the *pending* state. A `card`-tagged
 * discriminated union: a tool declares its render INTENT once and a UI bridge
 * switches on `card` to map it to the bridge's own wire shape. Provider-neutral —
 * the tool owns its presentation, so a UI never special-cases tool names.
 *
 * Returned by `ToolDefinition.presentCall`. See the render-intent-union
 * RFC (docs/rfc/implemented/architecture/2026-07-02-tool-render-intent-union.md).
 */
export type ToolCallView = GenericCallView | TerminalCallView | DiffCallView

/**
 * The default card: a titled tool-call row with an optional category icon, a
 * salient raw input, extra content blocks, and follow-along file locations. Any
 * tool whose call is not a terminal or a diff uses this.
 */
export interface GenericCallView {
  card: 'generic'
  /**
   * Human-readable, always-visible label describing what THIS call does. Keep it
   * short — a UI shows it as a card header / log line.
   */
  title: string
  /** Category for icon/treatment; defaults to `other` when omitted. */
  kind?: ToolCallKind
  /**
   * The salient input to surface in a detail/expanded view (e.g. a background
   * task id). Omit to show nothing; a string renders as-is, an object as pretty
   * JSON. NOT the full raw args object unless that is genuinely what a reader wants.
   */
  rawInput?: unknown
  /**
   * UI-facing content blocks to show on the pending call alongside the title.
   * Omit to show none. A UI maps these to its own content blocks.
   */
  content?: ContentBlock[]
  /** Files this call reads/modifies, for editor follow-along. Omit for a call that touches no file. */
  locations?: FileLocation[]
}

/**
 * A call that IS a shell command running in a working directory: a capable UI
 * renders it as a terminal card (cwd-headed, with the command as the title and
 * live/afterward output from the {@link TerminalResultView}); an incapable UI
 * falls back to a generic card whose body is the fenced command output. Set by a
 * tool whose call is a foreground command (e.g. `bash`).
 */
export interface TerminalCallView {
  card: 'terminal'
  /** The command, shown as the terminal card's title / header line. */
  title: string
  /**
   * A human-readable one-line summary of what the command does, rendered ABOVE
   * the terminal card (the card itself has no description slot). Omit for none.
   */
  description?: string
  /**
   * Working directory the command runs in, shown as the terminal header. An
   * ABSOLUTE path is used as-is; a RELATIVE path is resolved by the UI bridge
   * against the session workspace (the pure presenter can't see the session cwd).
   * Omit entirely to let the bridge use the session workspace.
   */
  cwd?: string
}

/**
 * A call that creates or modifies files, rendered as an inline diff card by a
 * capable UI. Set by a tool whose call writes/edits a file (e.g. `write`,
 * `edit`). The diffs are derived from the call ARGUMENTS (a create's `oldText` is
 * `null`); the tool emits a separate {@link DiffResultView} after `execute` — the
 * applied change (an edit/overwrite hunk with context, or a whole-file diff for a
 * create).
 */
export interface DiffCallView {
  card: 'diff'
  /** Card header (e.g. `Write foo.txt`). */
  title: string
  /** One entry per file the call changes. */
  diffs: FileDiff[]
  /** Files this call modifies, for editor follow-along (usually the diffs' paths). */
  locations?: FileLocation[]
}

/**
 * How a tool wants the COMPLETED call shown — the *result* state, after `execute`
 * returns. A `card`-tagged union mirroring {@link ToolCallView}: a UI switches on
 * `card`. Lets the tool reformat its result for a UI distinctly from the
 * model-facing text it returned from `execute`. Returned by
 * `ToolDefinition.presentResult`; omitting the method keeps the pending
 * title and renders the raw result content.
 */
export type ToolResultView = GenericResultView | TerminalResultView | DiffResultView

/**
 * The default completed card: an optional replacement title and reformatted
 * content. Omit a field to keep the pending title / render the raw result content.
 */
export interface GenericResultView {
  card: 'generic'
  /** Replacement title for the completed call. Omit to keep the pending-state title. */
  title?: string
  /**
   * UI-facing result content (harness {@link ContentBlock}s), reformatted from
   * the model-facing result. Omit to let the UI render the raw result content.
   */
  content?: ContentBlock[]
}

/**
 * The completed state of a {@link TerminalCallView}: the captured output and exit
 * status. A capable UI renders `output` in the terminal card and shows an
 * exit-status pill; an incapable UI gets a fenced ```console fallback the BRIDGE
 * derives from `output` (the tool does not double-encode it).
 */
export interface TerminalResultView {
  card: 'terminal'
  /** Replacement title for the completed call. Omit to keep the pending-state title. */
  title?: string
  /** Captured command output (stdout+stderr as the tool chooses to combine them). */
  output?: string
  /**
   * Process exit code, when the run ended by exiting (not a signal). Lets a
   * capable UI show an exit-status pill. Omit when killed by a signal or unknown.
   */
  exitCode?: number
  /** Signal name that killed the process (e.g. `SIGTERM`). Mutually exclusive with `exitCode`. */
  signal?: string
}

/**
 * A completed file mutation rendered as an inline diff card, the *result-time*
 * analogue of {@link DiffCallView}. Set by a tool whose `execute` applied a file
 * change (e.g. `write`, `edit`): `diffs` are the change to show — typically the
 * APPLIED hunks computed from the before/after content (one entry per hunk, each
 * with surrounding context lines), so the editor shows the real change in place;
 * a tool with no before-image (e.g. a file create) may instead give a whole-file
 * diff (`oldText: null`). A `tool_call_update`'s content REPLACES the call's
 * content in an editor, so a mutation tool returns this even when it duplicates
 * the call-time snippet — otherwise the model-facing result text would replace
 * (clobber) the pending diff card.
 */
export interface DiffResultView {
  card: 'diff'
  /** Replacement title for the completed call. Omit to keep the pending-state title. */
  title?: string
  /** The change to show, in file order — applied contextual hunks, or a whole-file diff when there is no before-image. */
  diffs: FileDiff[]
}