/**
 * Qoder context-window tiers + routable model listing.
 *
 * The Qoder IDE lets a user pick 200K / 400K / 1M for a model; qodercli-style
 * requests (what 9router sends) only carry the default max_input_tokens. These
 * tests pin the escalation policy and the payload fields the IDE writes.
 */
import { describe, it, expect } from "vitest";

import {
  parseTierTokenCount,
  getQoderContextTiers,
  estimateQoderPromptTokens,
  resolveQoderContextTier,
  applyQoderContextTier,
} from "../../open-sse/shared/qoder/contextTier.js";
import { routableQoderModels } from "../../open-sse/services/qoderModels.js";

// Shape mirrors the live /algo/api/v2/model/list entry for qmodel_38max.
const MODEL_CONFIG = {
  key: "qmodel_38max",
  display_name: "Qwen3.8-Max",
  is_reasoning: true,
  max_input_tokens: 180_000,
  max_output_tokens: 32_768,
  context_config: [
    { name: "200K", tokenCount: 200_000, isDefault: true },
    { name: "400K", tokenCount: 400_000, isDefault: false },
    { name: "1M", tokenCount: 1_000_000, isDefault: false },
  ],
};

function promptOfTokens(n) {
  // ~4 ASCII chars per token
  return { system: "", messages: [{ role: "user", content: "abcd".repeat(n) }], tools: [] };
}

describe("parseTierTokenCount", () => {
  it("accepts numbers and K/M suffixed strings", () => {
    expect(parseTierTokenCount(204800)).toBe(204800);
    expect(parseTierTokenCount("200K")).toBe(200_000);
    expect(parseTierTokenCount("1M")).toBe(1_000_000);
    expect(parseTierTokenCount("1.5m")).toBe(1_500_000);
    expect(parseTierTokenCount("131072")).toBe(131072);
  });

  it("returns 0 for garbage", () => {
    expect(parseTierTokenCount(null)).toBe(0);
    expect(parseTierTokenCount("big")).toBe(0);
    expect(parseTierTokenCount(-5)).toBe(0);
  });
});

describe("getQoderContextTiers", () => {
  it("sorts tiers ascending and keeps the default flag", () => {
    const tiers = getQoderContextTiers({
      context_config: [
        { name: "1M", tokenCount: 1_000_000 },
        { name: "200K", tokenCount: 200_000, isDefault: true },
      ],
    });
    expect(tiers.map((t) => t.tokenCount)).toEqual([200_000, 1_000_000]);
    expect(tiers[0].isDefault).toBe(true);
    expect(tiers[1].isDefault).toBe(false);
  });

  it("understands camelCase / snake_case variants and derives names", () => {
    const tiers = getQoderContextTiers({
      contextConfig: [{ token_count: "400K", is_default: true }, { max_input_tokens: 1_000_000 }],
    });
    expect(tiers).toEqual([
      { name: "400K", tokenCount: 400_000, isDefault: true },
      { name: "1M", tokenCount: 1_000_000, isDefault: false },
    ]);
  });

  it("returns [] when the model has no tiers", () => {
    expect(getQoderContextTiers({ max_input_tokens: 131072 })).toEqual([]);
    expect(getQoderContextTiers(null)).toEqual([]);
  });
});

describe("estimateQoderPromptTokens", () => {
  it("counts CJK characters as ~1 token each instead of chars/4", () => {
    const ascii = estimateQoderPromptTokens({ messages: [{ role: "user", content: "a".repeat(4000) }] });
    const cjk = estimateQoderPromptTokens({ messages: [{ role: "user", content: "中".repeat(4000) }] });
    expect(ascii).toBeLessThan(1_200);
    expect(cjk).toBeGreaterThan(4_000);
  });
});

describe("resolveQoderContextTier (auto)", () => {
  it("leaves the payload untouched while the prompt fits the current max_input_tokens", () => {
    expect(resolveQoderContextTier(MODEL_CONFIG, promptOfTokens(50_000))).toBeNull();
  });

  it("escalates to the smallest tier that fits once the prompt outgrows the default", () => {
    const choice = resolveQoderContextTier(MODEL_CONFIG, promptOfTokens(250_000));
    expect(choice).not.toBeNull();
    expect(choice.tier.name).toBe("400K");
    expect(choice.reason).toBe("auto:fits");
    expect(choice.estimatedTokens).toBeGreaterThan(240_000);
  });

  it("falls back to the largest tier when nothing fits (upstream decides)", () => {
    const choice = resolveQoderContextTier(MODEL_CONFIG, promptOfTokens(1_200_000));
    expect(choice.tier.name).toBe("1M");
    expect(choice.reason).toBe("auto:largest");
  });

  it("applies headroom so a prompt just under the limit still escalates", () => {
    // 170K estimated * 1.15 = 195.5K > 180K current → smallest tier above the current limit (200K)
    expect(resolveQoderContextTier(MODEL_CONFIG, promptOfTokens(170_000))?.tier.name).toBe("200K");
    // 190K * 1.15 = 218.5K → 200K no longer fits → 400K
    expect(resolveQoderContextTier(MODEL_CONFIG, promptOfTokens(190_000))?.tier.name).toBe("400K");
  });

  it("returns null for models without context_config", () => {
    expect(resolveQoderContextTier({ max_input_tokens: 131072 }, promptOfTokens(500_000))).toBeNull();
  });

  it("never escalates when the current limit is already the largest tier", () => {
    const cfg = { ...MODEL_CONFIG, max_input_tokens: 1_000_000 };
    expect(resolveQoderContextTier(cfg, promptOfTokens(1_500_000))).toBeNull();
  });
});

describe("resolveQoderContextTier (forced via QODER_CONTEXT_TIER)", () => {
  it("max picks the largest tier regardless of prompt size", () => {
    const choice = resolveQoderContextTier(MODEL_CONFIG, promptOfTokens(10), { preference: "max" });
    expect(choice.tier.name).toBe("1M");
    expect(choice.reason).toBe("forced:max");
  });

  it("default picks the isDefault tier", () => {
    const choice = resolveQoderContextTier(MODEL_CONFIG, promptOfTokens(10), { preference: "default" });
    expect(choice.tier.name).toBe("200K");
  });

  it("a tier name or token count selects that tier", () => {
    expect(resolveQoderContextTier(MODEL_CONFIG, promptOfTokens(10), { preference: "400k" }).tier.tokenCount).toBe(400_000);
    expect(resolveQoderContextTier(MODEL_CONFIG, promptOfTokens(10), { preference: "1000000" }).tier.name).toBe("1M");
  });

  it("an unknown tier name falls back to auto", () => {
    expect(resolveQoderContextTier(MODEL_CONFIG, promptOfTokens(10), { preference: "9M" })).toBeNull();
    expect(resolveQoderContextTier(MODEL_CONFIG, promptOfTokens(250_000), { preference: "9M" }).tier.name).toBe("400K");
  });
});

describe("applyQoderContextTier", () => {
  it("mirrors the tier into the three places the IDE writes", () => {
    const payload = {
      parameters: { max_tokens: 32_768 },
      chat_context: { extra: { context: [], modelConfig: { key: "qmodel_38max" } } },
      model_config: { ...MODEL_CONFIG },
    };
    applyQoderContextTier(payload, { name: "1M", tokenCount: 1_000_000 });
    expect(payload.parameters).toEqual({ max_tokens: 32_768, context_length: 1_000_000 });
    expect(payload.chat_context.extra.ideModelConfigOverride).toEqual({ max_input_tokens: 1_000_000 });
    expect(payload.chat_context.extra.modelConfig).toEqual({ key: "qmodel_38max" });
    expect(payload.model_config.max_input_tokens).toBe(1_000_000);
    expect(payload.model_config.context_config).toHaveLength(3);
  });

  it("is a no-op without a tier", () => {
    const payload = { parameters: { max_tokens: 1 } };
    expect(applyQoderContextTier(payload, null)).toBe(payload);
    expect(payload).toEqual({ parameters: { max_tokens: 1 } });
  });
});

describe("routableQoderModels", () => {
  it("lists visible models first, then hidden (enable:false) catalog keys", () => {
    const catalog = {
      models: [{ id: "qmodel_38max", name: "Qwen3.8-Max" }],
      rawConfigs: new Map([
        ["qmodel_38max", { key: "qmodel_38max", enable: true }],
        ["qfmodel", { key: "qfmodel", enable: false, display_name: "Qwen Fast" }],
        ["dmodel", { key: "dmodel", enable: false }],
      ]),
    };
    expect(routableQoderModels(catalog)).toEqual([
      { id: "qmodel_38max", name: "Qwen3.8-Max", hidden: false },
      { id: "qfmodel", name: "Qwen Fast", hidden: true },
      { id: "dmodel", name: "dmodel", hidden: true },
    ]);
  });

  it("returns [] for a failed catalog fetch", () => {
    expect(routableQoderModels(null)).toEqual([]);
  });
});