// ---------------------------------------------------------------------------
// caduceus — extension entry
//
// The ONLY file in caduceus that imports from pi. Per INIT.md §4 DNA-1,
// this is the SHELL: it talks to pi. All other modules are MEAT: pure,
// testable, independent of pi's runtime.
//
// v0.5.0 wiring: registers 21 slash commands across 3 sub-modules:
//   - lib/slash-commands-core.ts    (14 v0.1.0–v0.4.0 commands)
//   - lib/slash-commands-sdd.ts     (5 new SDD commands)
//   - lib/slash-commands-review.ts  (6 new review commands)
// ---------------------------------------------------------------------------

import type { ExtensionAPI } from "@earendil-works/pi-coding-agent";

import {
  readConfig,
  writeGlobalConfigField,
  DEFAULT_CONFIG,
  type EffectiveConfig,
  type PersonaMode,
  type SystemPromptMode,
  type PersonaName,
} from "../lib/config-store.ts";
import { buildPersonaPrompt } from "../lib/persona-contract.ts";
import { detectLocale, type ResolvedLocale } from "../lib/locale-detect.ts";
import {
  registerAllSlashCommands,
  defaultRenderInspectOutput,
} from "../lib/slash-commands.ts";
import {
  sddInit,
  sddExplore,
  sddPropose,
  sddApply,
  sddArchive,
  readActiveChange,
} from "../lib/sdd-flow.ts";
import {
  inspectReview,
  startReview,
  advanceReview,
  finalizeReview,
  validateReview,
  resetReview,
} from "../lib/review-state-machine.ts";
import { composeSystemPrompt } from "../lib/prompt-mode.ts";
import {
  loadPersona,
  listPersonas,
  type LoadedPersona,
} from "../lib/persona-loader.ts";
import { lintPersonaContent } from "../lib/lint.ts";
import {
  listProfiles as listProfilesFn,
  loadProfile as loadProfileFn,
  saveProfile as saveProfileFn,
  deleteProfile as deleteProfileFn,
} from "../lib/profile-store.ts";
import { personaDiff } from "../lib/diff.ts";
import {
  validateStep as validateWizardStep,
  generatePersonaContent as generateWizardContent,
  personaFilePath as wizardFilePath,
  writeAndLint,
} from "../lib/wizard.ts";
import { CADUCEUS_VERSION } from "../lib/version.ts";
import { CaduceusConfigError } from "../lib/errors.ts";

// v0.3.0: lib/language-clause.ts was removed. The persona prompt is
// no longer appended with a mode-specific language clause.

// CADUCEUS_VERSION is exported for downstream consumers; not used in this
// file directly but kept here for self-identification and future log lines.
void CADUCEUS_VERSION;

/**
 * Default export — the pi extension factory.
 */
export default function caduceus(pi: ExtensionAPI): void {
  // Per-session state (closure variables)
  let effective: EffectiveConfig | null = null;
  let cwd: string | null = null;
  let loadedPersona: LoadedPersona | null = null;
  let systemPromptMode: SystemPromptMode = "append";

  // -----------------------------------------------------------------------
  // 1. session_start
  // -----------------------------------------------------------------------
  pi.on("session_start", async (_event, ctx) => {
    cwd = ctx.cwd;
    try {
      effective = readConfig({ cwd: ctx.cwd });
    } catch (err) {
      if (err instanceof CaduceusConfigError) {
        ctx.ui.notify(
          `caduceus: malformed ${err.path}, using built-in defaults`,
          "warning",
        );
      }
      effective = {
        config: { ...DEFAULT_CONFIG },
        source: "built-in defaults",
      };
    }
    // Load the active persona (catch errors so the session still starts)
    try {
      loadedPersona = loadPersona(effective.config.persona, ctx.cwd);
    } catch (err) {
      // PersonaNot found — fall back to default and notify
      ctx.ui.notify(
        `caduceus: persona '${effective.config.persona}' not found, using 'default'`,
        "warning",
      );
      effective = {
        config: { ...effective.config, persona: "default" },
        source: effective.source,
      };
      loadedPersona = loadPersona("default", ctx.cwd);
    }
    // Sync the system-prompt mode from config
    systemPromptMode = effective.config.systemPromptMode;
    // Set the status bar (if enabled)
    if (effective.config.showStatusBar) {
      ctx.ui.setStatus(
        "caduceus",
        `caduceus · ${effective.config.persona} · ${effective.config.mode} · ${effective.config.locale}`,
      );
    }
  });

  // -----------------------------------------------------------------------
  // 2. before_agent_start
  // -----------------------------------------------------------------------
  pi.on("before_agent_start", async (event, _ctx) => {
    const cfg = effective?.config ?? DEFAULT_CONFIG;
    // v0.3.0: mode names are "default" and "plain" (replacing "gentleman" / "neutral")
    const mode: PersonaMode = cfg.mode === "plain" ? "plain" : "default";
    const locale: ResolvedLocale = detectLocale(event.prompt, process.env, cfg.locale);

    // Use the loaded persona if it matches the current config; otherwise
    // re-load. This handles persona changes via /caduceus:persona.
    const targetName = cfg.persona;
    if (!loadedPersona || loadedPersona.name !== targetName) {
      try {
        loadedPersona = loadPersona(targetName, cwd ?? process.cwd());
      } catch {
        // Should not happen — session_start already validates
        loadedPersona = loadPersona("default", cwd ?? process.cwd());
      }
    }

    // Render the persona: substitute ${mode} with the resolved mode.
    // v0.3.0: no language clause is appended; the persona prompt is
    // language-neutral and the model is expected to detect the user's
    // input language naturally.
    const renderedContent = loadedPersona.content.split("${mode}").join(mode);
    const persona = renderedContent.trim();

    return {
      systemPrompt: composeSystemPrompt(
        event.systemPrompt,
        persona,
        systemPromptMode,
      ),
    };
  });

  // -----------------------------------------------------------------------
  // 3-9. Slash commands (21 total: 10 core + 5 SDD + 6 review)
  // -----------------------------------------------------------------------
  registerAllSlashCommands(pi, {
    core: {
      readConfig: (cwd: string) => effective ?? readConfig({ cwd }),
      buildPersonaPrompt,
      writeGlobalConfigField,
      getStatusLine: (cfg) => `caduceus · ${cfg.mode} · ${cfg.locale}`,
      renderInspectOutput: defaultRenderInspectOutput,
      // v0.1.1:
      listPersonas: (cwd: string) => listPersonas(cwd),
      switchPersona: async (name: PersonaName) => {
        // 1. Re-load the persona content (validates it exists)
        const p = loadPersona(name, cwd ?? process.cwd());
        loadedPersona = p;
        // 2. Persist the choice to global config
        await writeGlobalConfigField("persona", name);
        // 3. Update the effective config snapshot
        if (effective) {
          effective = {
            config: { ...effective.config, persona: name },
            source: effective.source,
          };
        }
      },
      setSystemPromptMode: async (mode: SystemPromptMode) => {
        systemPromptMode = mode;
        await writeGlobalConfigField("systemPromptMode", mode);
        if (effective) {
          effective = {
            config: { ...effective.config, systemPromptMode: mode },
            source: effective.source,
          };
        }
      },
      lintActivePersona: () => {
        if (!loadedPersona) {
          return { passed: true, issues: [] };
        }
        return lintPersonaContent(loadedPersona.content, loadedPersona.name);
      },
      getActivePersonaName: () =>
        loadedPersona?.name ?? DEFAULT_CONFIG.persona,
      // v0.4.0 profiles:
      listProfiles: (cwd: string) => listProfilesFn(cwd),
      loadProfile: (name: string, cwd: string) => loadProfileFn(name, cwd),
      saveProfile: (
        name: string,
        profile: {
          mode: "default" | "plain" | "auto";
          locale: string;
          systemPromptMode: "append" | "replace";
          persona: string;
        },
        cwd: string,
      ) => saveProfileFn(name, profile, cwd),
      deleteProfile: (name: string, cwd: string) => deleteProfileFn(name, cwd),
      // v0.2.0 wizard:
      validateWizardStep,
      generateWizardContent,
      wizardFilePath,
      writeAndLint,
      // v0.2.0 diff:
      personaDiff,
    },
    sdd: {
      sddInit,
      sddExplore,
      sddPropose,
      sddApply,
      sddArchive,
      readActiveChange,
    },
    review: {
      inspectReview,
      startReview,
      advanceReview,
      finalizeReview,
      validateReview,
      // v0.6.0: real archive+clear implementation (was a no-op stub in v0.5.0)
      resetReview: (
        changeName: string,
        cwd: string,
      ): { ok: true; archivedPath: string } | { ok: false; reason: string } =>
        resetReview(changeName, cwd),
      inspectIsCorrupted: (changeName: string, cwd: string) =>
        inspectReview(changeName, cwd).state === "corrupted",
      getActivePersonaName: () =>
        loadedPersona?.name ?? DEFAULT_CONFIG.persona,
    },
  });
}

// ---------------------------------------------------------------------------
// (v0.3.0: language-clause lookup was removed; the persona prompt is
// language-neutral now.)
// ---------------------------------------------------------------------------