import { applyPatch } from "diff";
import { describe, expect, it } from "vitest";
import { NodeExecutionEnv } from "../../src/harness/env/nodejs.ts";
import { createBashTool } from "../../src/harness/tools/bash.ts";
import { createEditTool } from "../../src/harness/tools/edit.ts";
import { createReadTool } from "../../src/harness/tools/read.ts";
import { createWriteTool } from "../../src/harness/tools/write.ts";
import { getOrThrow } from "../../src/harness/types.ts";
import { createTempDir } from "./session-test-utils.ts";

function textOutput(result: { content: Array<{ type: string; text?: string }> }): string {
	return result.content.flatMap((part) => (part.type === "text" ? [part.text ?? ""] : [])).join("\n");
}

function createContext() {
	const env = new NodeExecutionEnv({ cwd: createTempDir() });
	return { env, sessionId: "session-1" };
}

function createTinyBmp(): Uint8Array {
	const bytes = new Uint8Array(58);
	const view = new DataView(bytes.buffer);
	bytes[0] = 0x42;
	bytes[1] = 0x4d;
	view.setUint32(2, bytes.length, true);
	view.setUint32(10, 54, true);
	view.setUint32(14, 40, true);
	view.setInt32(18, 1, true);
	view.setInt32(22, 1, true);
	view.setUint16(26, 1, true);
	view.setUint16(28, 24, true);
	view.setUint32(34, 4, true);
	return bytes;
}

describe("AgentHarness tools", () => {
	describe("read", () => {
		it("reads text with offsets, limits, and continuation notices", async () => {
			const context = createContext();
			getOrThrow(
				await context.env.writeFile(
					"test.txt",
					Array.from({ length: 100 }, (_, index) => `Line ${index + 1}`).join("\n"),
				),
			);

			const result = await createReadTool().execute(
				"read-1",
				{ path: "test.txt", offset: 41, limit: 20 },
				undefined,
				undefined,
				context,
			);
			const output = textOutput(result);

			expect(output).not.toContain("Line 40");
			expect(output).toContain("Line 41");
			expect(output).toContain("Line 60");
			expect(output).not.toContain("Line 61");
			expect(output).toContain("[40 more lines in file. Use offset=61 to continue.]");
		});

		it("truncates large text by line count", async () => {
			const context = createContext();
			getOrThrow(
				await context.env.writeFile(
					"large.txt",
					Array.from({ length: 2500 }, (_, index) => `Line ${index + 1}`).join("\n"),
				),
			);

			const result = await createReadTool().execute("read-2", { path: "large.txt" }, undefined, undefined, context);

			expect(textOutput(result)).toContain("[Showing lines 1-2000 of 2500. Use offset=2001 to continue.]");
			expect(result.details?.truncation).toMatchObject({
				truncated: true,
				truncatedBy: "lines",
				totalLines: 2500,
				outputLines: 2000,
			});
		});

		it("rejects offsets beyond the file", async () => {
			const context = createContext();
			getOrThrow(await context.env.writeFile("short.txt", "one\ntwo\nthree"));

			await expect(
				createReadTool().execute("read-3", { path: "short.txt", offset: 100 }, undefined, undefined, context),
			).rejects.toThrow("Offset 100 is beyond end of file (3 lines total)");
		});

		it("detects supported images by content", async () => {
			const context = createContext();
			const png = Uint8Array.from(
				Buffer.from(
					"iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR4nGNgYGD4DwABBAEAX+XDSwAAAABJRU5ErkJggg==",
					"base64",
				),
			);
			getOrThrow(await context.env.writeFile("image.txt", png));

			const result = await createReadTool().execute("read-4", { path: "image.txt" }, undefined, undefined, context);

			expect(textOutput(result)).toContain("Read image file [image/png]");
			expect(result.content).toContainEqual({
				type: "image",
				data: Buffer.from(png).toString("base64"),
				mimeType: "image/png",
			});
		});

		it("delegates image conversion and resizing to an injected processor", async () => {
			const context = createContext();
			const bmp = createTinyBmp();
			getOrThrow(await context.env.writeFile("image.bmp", bmp));
			let received: { bytes: Uint8Array; mimeType: string; autoResizeImages: boolean } | undefined;
			const tool = createReadTool({
				autoResizeImages: false,
				imageProcessor: async (bytes, mimeType, options) => {
					received = { bytes, mimeType, autoResizeImages: options.autoResizeImages };
					return {
						ok: true,
						data: "converted",
						mimeType: "image/png",
						hints: ["[Image converted from image/bmp to image/png.]"],
					};
				},
			});

			const result = await tool.execute("read-bmp", { path: "image.bmp" }, undefined, undefined, context);

			expect(received).toMatchObject({ mimeType: "image/bmp", autoResizeImages: false });
			expect(Array.from(received?.bytes ?? [])).toEqual(Array.from(bmp));
			expect(textOutput(result)).toContain("[Image converted from image/bmp to image/png.]");
			expect(result.content).toContainEqual({ type: "image", data: "converted", mimeType: "image/png" });
		});
	});

	describe("write", () => {
		it("writes files and creates parent directories", async () => {
			const context = createContext();
			const result = await createWriteTool().execute(
				"write-1",
				{ path: "nested/dir/file.txt", content: "hello" },
				undefined,
				undefined,
				context,
			);

			expect(textOutput(result)).toBe("Successfully wrote 5 bytes to nested/dir/file.txt");
			expect(getOrThrow(await context.env.readTextFile("nested/dir/file.txt"))).toBe("hello");
		});
	});

	describe("edit", () => {
		it("applies disjoint edits and returns both diff formats", async () => {
			const context = createContext();
			const original = "alpha\nbeta\ngamma\ndelta\n";
			getOrThrow(await context.env.writeFile("edit.txt", original));

			const result = await createEditTool().execute(
				"edit-1",
				{
					path: "edit.txt",
					edits: [
						{ oldText: "alpha\n", newText: "ALPHA\n" },
						{ oldText: "gamma\n", newText: "GAMMA\n" },
					],
				},
				undefined,
				undefined,
				context,
			);

			expect(textOutput(result)).toBe("Successfully replaced 2 block(s) in edit.txt.");
			expect(result.details?.diff).toContain("ALPHA");
			expect(result.details?.diff).toContain("GAMMA");
			expect(applyPatch(original, result.details?.patch ?? "")).toBe("ALPHA\nbeta\nGAMMA\ndelta\n");
			expect(getOrThrow(await context.env.readTextFile("edit.txt"))).toBe("ALPHA\nbeta\nGAMMA\ndelta\n");
		});

		it("matches all edits against the original and rejects overlaps", async () => {
			const context = createContext();
			getOrThrow(await context.env.writeFile("edit.txt", "one\ntwo\nthree\n"));

			await expect(
				createEditTool().execute(
					"edit-2",
					{
						path: "edit.txt",
						edits: [
							{ oldText: "one\ntwo\n", newText: "ONE\nTWO\n" },
							{ oldText: "two\nthree\n", newText: "TWO\nTHREE\n" },
						],
					},
					undefined,
					undefined,
					context,
				),
			).rejects.toThrow(/overlap/);
			expect(getOrThrow(await context.env.readTextFile("edit.txt"))).toBe("one\ntwo\nthree\n");
		});

		it("rejects missing and duplicate target text", async () => {
			const context = createContext();
			getOrThrow(await context.env.writeFile("edit.txt", "foo foo foo"));
			const tool = createEditTool();

			await expect(
				tool.execute(
					"edit-3",
					{ path: "edit.txt", edits: [{ oldText: "bar", newText: "baz" }] },
					undefined,
					undefined,
					context,
				),
			).rejects.toThrow(/Could not find the exact text/);
			await expect(
				tool.execute(
					"edit-4",
					{ path: "edit.txt", edits: [{ oldText: "foo", newText: "bar" }] },
					undefined,
					undefined,
					context,
				),
			).rejects.toThrow(/Found 3 occurrences/);
		});

		it("preserves BOM and CRLF line endings", async () => {
			const context = createContext();
			getOrThrow(await context.env.writeFile("edit.txt", "\uFEFFone\r\ntwo\r\n"));

			await createEditTool().execute(
				"edit-5",
				{ path: "edit.txt", edits: [{ oldText: "two", newText: "TWO" }] },
				undefined,
				undefined,
				context,
			);

			expect(getOrThrow(await context.env.readTextFile("edit.txt"))).toBe("\uFEFFone\r\nTWO\r\n");
		});
	});

	describe("bash", () => {
		it("executes commands and combines stdout and stderr", async () => {
			const context = createContext();
			const result = await createBashTool().execute(
				"bash-1",
				{ command: "printf out; printf err >&2" },
				undefined,
				undefined,
				context,
			);

			expect(textOutput(result)).toContain("out");
			expect(textOutput(result)).toContain("err");
		});

		it("reports nonzero exits and timeouts", async () => {
			const context = createContext();
			const tool = createBashTool();

			await expect(
				tool.execute("bash-2", { command: "printf failed; exit 7" }, undefined, undefined, context),
			).rejects.toThrow(/failed[\s\S]*Command exited with code 7/);
			await expect(
				tool.execute("bash-3", { command: "sleep 2", timeout: 0.01 }, undefined, undefined, context),
			).rejects.toThrow(/Command timed out after 0.01 seconds/);
		});

		it("preserves truncated output when a command times out", async () => {
			const context = createContext();
			let error: unknown;
			try {
				await createBashTool().execute(
					"bash-timeout-output",
					{
						command: "i=1; while [ $i -le 3000 ]; do echo line-$i; i=$((i + 1)); done; sleep 2",
						timeout: 0.05,
					},
					undefined,
					undefined,
					context,
				);
			} catch (cause) {
				error = cause;
			}

			expect(error).toBeInstanceOf(Error);
			const message = (error as Error).message;
			expect(message).toContain("Command timed out after 0.05 seconds");
			const fullOutputPath = message.match(/Full output: ([^\]\n]+)/)?.[1];
			expect(fullOutputPath).toBeDefined();
			const fullOutput = getOrThrow(await context.env.readTextFile(fullOutputPath!));
			expect(fullOutput).toContain("line-1\nline-2");
			expect(fullOutput).toContain("line-2999\nline-3000");
		});

		it("supports command prefixes", async () => {
			const context = createContext();
			const result = await createBashTool({ commandPrefix: "value=hello" }).execute(
				"bash-4",
				{ command: "printf $value" },
				undefined,
				undefined,
				context,
			);

			expect(textOutput(result)).toBe("hello");
		});

		it("coalesces updates and persists truncated full output", async () => {
			const context = createContext();
			const updates: string[] = [];
			const result = await createBashTool().execute(
				"bash-5",
				{ command: "i=1; while [ $i -le 3000 ]; do echo line-$i; i=$((i + 1)); done" },
				undefined,
				(update) => updates.push(textOutput(update)),
				context,
			);

			expect(updates.length).toBeLessThan(25);
			expect(result.details?.truncation).toMatchObject({
				truncated: true,
				truncatedBy: "lines",
				totalLines: 3000,
				outputLines: 2000,
			});
			expect(textOutput(result)).toContain("line-3000");
			expect(result.details?.fullOutputPath).toBeDefined();
			const fullOutput = getOrThrow(await context.env.readTextFile(result.details!.fullOutputPath!));
			expect(fullOutput).toContain("line-1\nline-2");
			expect(fullOutput).toContain("line-2999\nline-3000");
		});
	});
});