import chalk from "chalk";
import dayjs from "dayjs";
import { define } from "gunshi";

import { openDb } from "@/db";
import * as syncRunsQ from "@/db/queries/sync-runs";
import { whatsNew } from "@/services/whats-new-service";
import { formatIso, parseToMs } from "@/utils/dates";

import { ExitCodes, exitWith, wrap } from "../envelope";
import { enterJsonMode, isJsonMode, printHuman, printJson } from "../output";

export const whatsNewCommand = define({
  name: "whats-new",
  description: "Aggregate new releases, price drops, and new magnets since a cutoff",
  args: {
    since: { type: "string", description: "Cutoff (YYYY-MM-DD, ISO, or ms)" },
    "since-last-sync": {
      type: "boolean",
      description: "Use the last successful sync's finished_at as the cutoff (default)"
    },
    author: {
      type: "string",
      short: "a",
      description: "Restrict results to a single author"
    },
    db: {
      type: "string",
      description: "SQLite DB path (default: ~/.fc2cma/db.sqlite or $FC2CMA_DB)"
    },
    json: { type: "boolean", description: "Emit machine-readable JSON envelope on stdout" }
  },
  run(ctx) {
    const args = ctx.values;
    enterJsonMode(Boolean(args.json));

    if (args.since && args["since-last-sync"]) {
      return exitWith(
        ExitCodes.USAGE,
        "whats-new: --since and --since-last-sync are mutually exclusive"
      );
    }

    const db = openDb(args.db);
    const warnings: string[] = [];

    let sinceMs: number;
    if (args.since) {
      try {
        sinceMs = parseToMs(args.since);
      } catch (err) {
        db.close();
        const msg = err instanceof Error ? err.message : String(err);
        return exitWith(ExitCodes.USAGE, `whats-new: ${msg}`);
      }
    } else {
      const lastRun = syncRunsQ.lastSuccessfulRun(db, args.author);
      if (lastRun && lastRun.finishedAt !== null) {
        sinceMs = lastRun.finishedAt;
      } else {
        sinceMs = dayjs().subtract(7, "day").valueOf();
        warnings.push("no successful sync found; defaulting to 7 days ago");
      }
    }

    const payload = whatsNew({ db, author: args.author ?? null, sinceMs });

    if (isJsonMode()) {
      printJson(wrap("whats-new", payload, warnings));
    } else {
      const sinceIso = formatIso(sinceMs);
      printHuman(chalk.bold(`since ${sinceIso}${args.author ? ` (author=${args.author})` : ""}`));
      printHuman(
        `  new releases: ${chalk.green(payload.counts.newReleases)}   price drops: ${chalk.green(payload.counts.priceDrops)}   new magnets: ${chalk.green(payload.counts.newMagnets)}`
      );
      if (payload.newReleases.length > 0) {
        printHuman(chalk.bold("\n  New releases:"));
        for (const r of payload.newReleases) {
          printHuman(`    ${chalk.cyan(r.id)}  ${r.author}  ${r.title}`);
        }
      }
      if (payload.priceDrops.length > 0) {
        printHuman(chalk.bold("\n  Price drops:"));
        for (const d of payload.priceDrops) {
          const pct = (d.pctDrop * 100).toFixed(0);
          printHuman(
            `    ${chalk.cyan(d.id)}  ¥${d.from.priceYen} → ¥${d.to.priceYen}  ${chalk.red(`(-${pct}%)`)}  ${d.title}`
          );
        }
      }
      for (const w of warnings) printHuman(chalk.yellow(`  warning: ${w}`));
    }
    db.close();
  }
});