// The ticket page's data model: one `ticket.data.js` per ticket and one `epic.data.js`
// per epic, each a single `window.X = <strict JSON>;` assignment so an open page can poll
// it with a <script> tag, where file:// and T3 Code's sandboxed viewer cannot fetch. Everything that reads or writes those files
// goes through this module, so the shape is defined once and validated on every write.

import { mkdirSync, readFileSync, renameSync, writeFileSync } from "node:fs";
import { dirname, join } from "node:path";

export type StepStatus = "todo" | "running" | "done";
export type StepKind = "code" | "mock" | "deliverable";

export interface Section {
  id: string;
  title: string;
  html: string;
  /** "jira" is imported verbatim from the ticket; "note" is written by the agent. */
  origin: "jira" | "note";
}

export interface Segment { t: number; text: string }

export interface Attachment {
  name: string;
  /** Relative to the ticket directory. */
  path: string;
  kind: "image" | "video" | "audio" | "file";
  bytes: number;
  transcript?: Segment[];
  frames?: string[];
}

export interface Criterion {
  id: string;
  text: string;
  steps: number[];
  status: "todo" | "done";
  doneAt?: string;
  evidence?: string;
}

export interface Step {
  n: number;
  text: string;
  kind: StepKind;
  tdd?: boolean;
  status: StepStatus;
  commits: string[];
  doneAt?: string;
}

export interface Risk { risk: string; handling: string; criteria?: string[]; fromTicket?: boolean }
export interface Test { text: string; kind: string; criteria?: string[]; fromTicket?: boolean }
/** A design artboard drawn at plan time. `criteria` names what it illustrates, so the
 *  Progress tab can show it beside the proof for those criteria. */
export interface Mock { id: string; title: string; note: string; html: string; criteria: string[] }

export interface Plan {
  writtenAt: string;
  approvedAt?: string;
  criteria: Criterion[];
  /** HTML fragments. Empty means none. */
  questions: string[];
  /** HTML. */
  approach: string;
  decisions: [question: string, choice: string, why: string][];
  steps: Step[];
  risks: Risk[];
  tests: Test[];
  mocks: Mock[];
}

export interface Proof {
  kind: "image" | "video" | "text" | "test";
  /** Relative to the ticket directory, for image and text proof. */
  file?: string;
  /** Embedded content of a text proof, because file:// pages cannot fetch it. */
  text?: string;
  /** The passing test's name, for test proof. */
  test?: string;
  proves: string[];
  caption: string;
  mock?: string;
  at: string;
}

export interface Finding {
  id: string;
  severity: "CONFIRMED" | "PLAUSIBLE";
  text: string;
  where?: string;
  status: "open" | "fixed" | "rejected";
  commit?: string;
  reason?: string;
  at: string;
}

export interface Event { at: string; kind: string; text: string; commit?: string }

export interface Ticket {
  schema: 1;
  key: string;
  title: string;
  type: string;
  status: string;
  priority: string;
  estimate?: string;
  assignee?: string;
  epic: { key: string; title: string } | null;
  jira: string;
  branch?: string;
  classified?: "bounded" | "architectural";
  links: { type: string; key: string; title: string }[];
  source: { importedAt: string; fields: [string, string][]; sections: Section[] };
  attachments: Attachment[];
  plan: Plan | null;
  proof: Proof[];
  review: {
    findings: Finding[];
    preMr: { verdict: string; recommendation?: string; head?: string; runs: number; at: string } | null;
  };
  jiraFields: { name: string; at: string }[];
  mr: { at: string } | null;
  events: Event[];
  updatedAt: string;
}

export type StoryStatus = "todo" | "planned" | "building" | "verifying" | "ready" | "done";

export interface Story {
  key: string;
  title: string;
  hours?: number;
  risk?: string;
  after: string[];
  status: StoryStatus;
  /** Set once a ticket page exists for the story, so the index can link to it. */
  page?: boolean;
  progress?: { criteria: [number, number]; steps: [number, number] };
}

export interface Epic {
  schema: 1;
  key: string;
  title: string;
  jira: string;
  /** Why the build order is what it is, one reason per entry. */
  why: string[];
  /** In build order. */
  stories: Story[];
  closed: { key: string; title: string }[];
  updatedAt: string;
}

export const now = () => new Date().toISOString();

const GLOBAL = { ticket: "TICKET", epic: "EPIC" } as const;

export function readData(file: string, kind: "ticket"): Ticket;
export function readData(file: string, kind: "epic"): Epic;
export function readData(file: string, kind: keyof typeof GLOBAL): Ticket | Epic {
  const raw = readFileSync(file, "utf8");
  const prefix = `window.${GLOBAL[kind]} = `;
  if (!raw.startsWith(prefix)) throw new Error(`${file} does not start with ${prefix.trim()}`);
  return JSON.parse(raw.slice(prefix.length).trim().replace(/;$/, ""));
}

/** Validates, then writes through a temp file and a rename so a page reloading
 *  the file mid-write never sees half of it. */
export function writeData(file: string, kind: "ticket", data: Ticket): void;
export function writeData(file: string, kind: "epic", data: Epic): void;
export function writeData(file: string, kind: keyof typeof GLOBAL, data: Ticket | Epic) {
  const problems = kind === "ticket" ? validateTicket(data as Ticket) : validateEpic(data as Epic);
  if (problems.length) throw new Error(`refusing to write ${file}:\n  - ${problems.join("\n  - ")}`);
  data.updatedAt = now();
  mkdirSync(dirname(file), { recursive: true });
  const tmp = join(dirname(file), `.${Date.now()}.${process.pid}.tmp`);
  writeFileSync(tmp, `window.${GLOBAL[kind]} = ${JSON.stringify(data, null, 1)};\n`);
  renameSync(tmp, file);
}


const isStr = (x: unknown): x is string => typeof x === "string";

export function validateTicket(t: Ticket): string[] {
  const p: string[] = [];
  if (t.schema !== 1) p.push("schema must be 1");
  for (const k of ["key", "title", "type", "status", "jira"] as const) if (!isStr(t[k]) || !t[k]) p.push(`${k} is required`);
  if (!Array.isArray(t.events)) p.push("events must be a list");
  if (!t.plan) return p;
  const plan = t.plan;
  const ids = new Set<string>();
  plan.criteria.forEach((c, i) => {
    if (!c.id || !c.text) p.push(`criterion ${i + 1} needs an id and text`);
    if (ids.has(c.id)) p.push(`criterion id ${c.id} is used twice`);
    ids.add(c.id);
    for (const n of c.steps) if (!plan.steps.some(s => s.n === n)) p.push(`${c.id} names step ${n}, which does not exist`);
  });
  plan.steps.forEach((s, i) => {
    if (s.n !== i + 1) p.push(`steps must be numbered 1..${plan.steps.length} in order, found ${s.n} at position ${i + 1}`);
    if (!["code", "mock", "deliverable"].includes(s.kind)) p.push(`step ${s.n} kind must be code, mock or deliverable`);
    if (!["todo", "running", "done"].includes(s.status)) p.push(`step ${s.n} status must be todo, running or done`);
  });
  const mockIds = new Set(plan.mocks.map(m => m.id));
  for (const m of plan.mocks) for (const c of m.criteria) if (!ids.has(c)) p.push(`mock ${m.id} names unknown criterion ${c}`);
  for (const r of plan.risks) for (const c of r.criteria ?? []) if (!ids.has(c)) p.push(`risk "${r.risk}" names unknown criterion ${c}`);
  for (const x of plan.tests) for (const c of x.criteria ?? []) if (!ids.has(c)) p.push(`test "${x.text}" names unknown criterion ${c}`);
  for (const pr of t.proof) {
    for (const c of pr.proves) if (!ids.has(c)) p.push(`proof ${pr.file ?? pr.test} names unknown criterion ${c}`);
    if (pr.mock && !mockIds.has(pr.mock)) p.push(`proof ${pr.file} names unknown mock ${pr.mock}`);
  }
  return p;
}

export function validateEpic(e: Epic): string[] {
  const p: string[] = [];
  if (e.schema !== 1) p.push("schema must be 1");
  if (!e.key || !e.title) p.push("key and title are required");
  const keys = new Set<string>();
  for (const s of e.stories) {
    if (keys.has(s.key)) p.push(`${s.key} appears twice in the order`);
    keys.add(s.key);
  }
  for (const s of e.stories) for (const a of s.after) if (!keys.has(a)) p.push(`${s.key} waits on ${a}, which is not in the epic`);
  return p;
}

/** Where a ticket stands, derived from its data rather than stored, so the page,
 *  the epic index and `show` can never disagree. */
export function storyStatus(t: Ticket): StoryStatus {
  if (!t.plan) return "todo";
  if (t.review.preMr?.verdict === "Ready to Open MR") return "ready";
  if (!t.plan.approvedAt) return "planned";
  return t.plan.steps.every(s => s.status === "done") ? "verifying" : "building";
}

export function progress(t: Ticket): Story["progress"] {
  const pl = t.plan;
  if (!pl) return { criteria: [0, 0], steps: [0, 0] };
  return {
    criteria: [pl.criteria.filter(c => c.status === "done").length, pl.criteria.length],
    steps: [pl.steps.filter(s => s.status === "done").length, pl.steps.length],
  };
}