import { describe, it } from "node:test";
import assert from "node:assert/strict";
import { comboRuntimeConfigSchema } from "@/shared/validation/schemas/combo";

// Test the context requirements schema extension against the real
// comboRuntimeConfigSchema export, so this test catches drift if the
// production schema changes shape.
describe("Combo Context Requirements", () => {
  describe("Schema Validation", () => {
    it("should accept valid minContextWindow", () => {
      const schema = comboRuntimeConfigSchema;

      const valid = [
        { contextRequirements: { minContextWindow: 8192 } },
        { contextRequirements: { minContextWindow: 32000 } },
        { contextRequirements: { minContextWindow: 128000 } },
        { contextRequirements: { minContextWindow: 1000000 } },
        { contextRequirements: {} },
        {},
      ];

      for (const input of valid) {
        const result = schema.safeParse(input);
        assert.ok(result.success, `Should accept ${JSON.stringify(input)}`);
      }
    });

    it("should reject invalid minContextWindow", () => {
      const schema = comboRuntimeConfigSchema;

      const invalid = [
        { contextRequirements: { minContextWindow: -1 } },
        { contextRequirements: { minContextWindow: 20_000_000 } },
        { contextRequirements: { minContextWindow: "invalid" } },
      ];

      for (const input of invalid) {
        const result = schema.safeParse(input);
        assert.ok(!result.success, `Should reject ${JSON.stringify(input)}`);
      }
    });

    it("should accept valid preferLargeContext boolean", () => {
      const schema = comboRuntimeConfigSchema;

      const valid = [
        { contextRequirements: { preferLargeContext: true } },
        { contextRequirements: { preferLargeContext: false } },
        { contextRequirements: {} },
      ];

      for (const input of valid) {
        const result = schema.safeParse(input);
        assert.ok(result.success, `Should accept ${JSON.stringify(input)}`);
      }
    });

    it("should accept valid contextFilterMode", () => {
      const schema = comboRuntimeConfigSchema;

      const valid = [
        { contextRequirements: { contextFilterMode: "strict" } },
        { contextRequirements: { contextFilterMode: "lenient" } },
        { contextRequirements: {} },
      ];

      for (const input of valid) {
        const result = schema.safeParse(input);
        assert.ok(result.success, `Should accept ${JSON.stringify(input)}`);
      }
    });

    it("should reject invalid contextFilterMode", () => {
      const schema = comboRuntimeConfigSchema;

      const invalid = [
        { contextRequirements: { contextFilterMode: "invalid" } },
        { contextRequirements: { contextFilterMode: "permissive" } },
      ];

      for (const input of invalid) {
        const result = schema.safeParse(input);
        assert.ok(!result.success, `Should reject ${JSON.stringify(input)}`);
      }
    });

    it("should accept combined context requirements", () => {
      const schema = comboRuntimeConfigSchema;

      const input = {
        contextRequirements: {
          minContextWindow: 32000,
          preferLargeContext: true,
          contextFilterMode: "strict" as const,
        },
      };

      const result = schema.safeParse(input);
      assert.ok(result.success);
      if (result.success) {
        assert.deepEqual(result.data, input);
      }
    });
  });

  describe("Context Filtering Logic", () => {
    it("should filter targets below minContextWindow in strict mode", () => {
      const targets = [
        { model: "gpt-3.5-turbo", contextWindow: 4096 },
        { model: "gpt-4", contextWindow: 8192 },
        { model: "gpt-4-turbo", contextWindow: 128000 },
        { model: "claude-3-opus", contextWindow: 200000 },
      ];

      const minContextWindow = 32000;
      const contextFilterMode = "strict";

      const filtered = targets.filter((t) => {
        const limit = t.contextWindow ?? null;
        if (limit === null) {
          // Unknown limits fail in strict mode
          return contextFilterMode === "lenient";
        }
        return limit >= minContextWindow;
      });

      assert.equal(filtered.length, 2);
      assert.equal(filtered[0].model, "gpt-4-turbo");
      assert.equal(filtered[1].model, "claude-3-opus");
    });

    it("should include unknown context limits in lenient mode", () => {
      const targets = [
        { model: "gpt-4", contextWindow: 8192 },
        { model: "custom-model", contextWindow: null },
        { model: "claude-3-opus", contextWindow: 200000 },
      ];

      const minContextWindow = 32000;
      const contextFilterMode = "lenient";

      const filtered = targets.filter((t) => {
        const limit = t.contextWindow ?? null;
        if (limit === null) {
          return contextFilterMode === "lenient";
        }
        return limit >= minContextWindow;
      });

      assert.equal(filtered.length, 2);
      assert.equal(filtered[0].model, "custom-model");
      assert.equal(filtered[1].model, "claude-3-opus");
    });

    it("should exclude unknown context limits in strict mode", () => {
      const targets = [
        { model: "gpt-4", contextWindow: 8192 },
        { model: "custom-model", contextWindow: null },
        { model: "claude-3-opus", contextWindow: 200000 },
      ];

      const minContextWindow = 32000;
      const contextFilterMode = "strict";

      const filtered = targets.filter((t) => {
        const limit = t.contextWindow ?? null;
        if (limit === null) {
          return contextFilterMode === "lenient";
        }
        return limit >= minContextWindow;
      });

      assert.equal(filtered.length, 1);
      assert.equal(filtered[0].model, "claude-3-opus");
    });

    it("should sort by context size when preferLargeContext is enabled", () => {
      const targets = [
        { model: "gpt-4", contextWindow: 8192 },
        { model: "claude-3-opus", contextWindow: 200000 },
        { model: "gpt-4-turbo", contextWindow: 128000 },
        { model: "gemini-pro", contextWindow: 1000000 },
      ];

      const preferLargeContext = true;

      const sorted = preferLargeContext
        ? [...targets].sort((a, b) => {
            const aLimit = a.contextWindow ?? 0;
            const bLimit = b.contextWindow ?? 0;
            return bLimit - aLimit; // Descending
          })
        : targets;

      assert.equal(sorted[0].model, "gemini-pro");
      assert.equal(sorted[1].model, "claude-3-opus");
      assert.equal(sorted[2].model, "gpt-4-turbo");
      assert.equal(sorted[3].model, "gpt-4");
    });

    it("should not sort when preferLargeContext is disabled", () => {
      const targets = [
        { model: "gpt-4", contextWindow: 8192 },
        { model: "claude-3-opus", contextWindow: 200000 },
        { model: "gpt-4-turbo", contextWindow: 128000 },
      ];

      const preferLargeContext = false;

      const sorted = preferLargeContext
        ? [...targets].sort((a, b) => (b.contextWindow ?? 0) - (a.contextWindow ?? 0))
        : targets;

      assert.equal(sorted[0].model, "gpt-4");
      assert.equal(sorted[1].model, "claude-3-opus");
      assert.equal(sorted[2].model, "gpt-4-turbo");
    });
  });

  describe("Integration with Existing Context Filtering", () => {
    it("should work with existing filterTargetsByRequestCompatibility logic", () => {
      // This test verifies the new config integrates with existing code
      // The actual implementation in comboStructure.ts already has context filtering
      // We just need to ensure our new config fields are respected

      const config = {
        contextRequirements: {
          minContextWindow: 32000,
          preferLargeContext: true,
          contextFilterMode: "strict" as const,
        },
      };

      const targets = [
        { model: "small-model", contextWindow: 4096 },
        { model: "medium-model", contextWindow: 32000 },
        { model: "large-model", contextWindow: 200000 },
        { model: "unknown-model", contextWindow: null },
      ];

      // Step 1: Filter by minContextWindow
      let filtered = targets.filter((t) => {
        const limit = t.contextWindow ?? null;
        if (config.contextRequirements.minContextWindow) {
          if (limit === null) {
            return config.contextRequirements.contextFilterMode === "lenient";
          }
          return limit >= config.contextRequirements.minContextWindow;
        }
        return true;
      });

      assert.equal(filtered.length, 2);

      // Step 2: Sort by context size if preferLargeContext
      if (config.contextRequirements.preferLargeContext) {
        filtered.sort((a, b) => {
          const aLimit = a.contextWindow ?? 0;
          const bLimit = b.contextWindow ?? 0;
          return bLimit - aLimit;
        });
      }

      assert.equal(filtered[0].model, "large-model");
      assert.equal(filtered[1].model, "medium-model");
    });
  });
});