import { DiffViewProvider, DIFF_VIEW_URI_SCHEME, DIFF_VIEW_LABEL_CHANGES } from "../DiffViewProvider"
import * as vscode from "vscode"
import * as path from "path"
import delay from "delay"

// Mock delay
vi.mock("delay", () => ({
	default: vi.fn().mockResolvedValue(undefined),
}))

// Mock fs/promises
vi.mock("fs/promises", () => ({
	readFile: vi.fn().mockResolvedValue("file content"),
	writeFile: vi.fn().mockResolvedValue(undefined),
}))

// Mock utils
vi.mock("../../../utils/fs", () => ({
	createDirectoriesForFile: vi.fn().mockResolvedValue([]),
}))

// Mock path
vi.mock("path", () => ({
	resolve: vi.fn((cwd, relPath) => `${cwd}/${relPath}`),
	basename: vi.fn((path) => path.split("/").pop()),
}))

// Mock vscode
vi.mock("vscode", () => ({
	workspace: {
		applyEdit: vi.fn(),
		onDidOpenTextDocument: vi.fn(() => ({ dispose: vi.fn() })),
		openTextDocument: vi.fn().mockResolvedValue({
			isDirty: false,
			save: vi.fn().mockResolvedValue(undefined),
		}),
		textDocuments: [],
		fs: {
			stat: vi.fn(),
		},
	},
	window: {
		createTextEditorDecorationType: vi.fn(),
		showTextDocument: vi.fn(),
		onDidChangeVisibleTextEditors: vi.fn(() => ({ dispose: vi.fn() })),
		onDidChangeActiveTextEditor: vi.fn(() => ({ dispose: vi.fn() })),
		tabGroups: {
			all: [],
			close: vi.fn(),
		},
		visibleTextEditors: [],
	},
	commands: {
		executeCommand: vi.fn(),
	},
	languages: {
		getDiagnostics: vi.fn(() => []),
	},
	DiagnosticSeverity: {
		Error: 0,
		Warning: 1,
		Information: 2,
		Hint: 3,
	},
	WorkspaceEdit: vi.fn().mockImplementation(() => ({
		replace: vi.fn(),
		delete: vi.fn(),
	})),
	ViewColumn: {
		Active: 1,
		Beside: 2,
		One: 1,
		Two: 2,
		Three: 3,
		Four: 4,
		Five: 5,
		Six: 6,
		Seven: 7,
		Eight: 8,
		Nine: 9,
	},
	Range: vi.fn(),
	Position: vi.fn(),
	Selection: vi.fn(),
	TextEditorRevealType: {
		InCenter: 2,
	},
	TabInputTextDiff: class TabInputTextDiff {},
	Uri: {
		file: vi.fn((path) => ({ fsPath: path })),
		parse: vi.fn((uri) => ({ with: vi.fn(() => ({})) })),
		from: vi.fn((options) => ({
			scheme: options.scheme,
			path: options.path,
			query: options.query,
		})),
	},
}))

// Mock DecorationController
vi.mock("../DecorationController", () => ({
	DecorationController: vi.fn().mockImplementation(() => ({
		setActiveLine: vi.fn(),
		updateOverlayAfterLine: vi.fn(),
		addLines: vi.fn(),
		clear: vi.fn(),
	})),
}))

describe("DiffViewProvider", () => {
	let diffViewProvider: DiffViewProvider
	const mockCwd = "/mock/cwd"
	let mockWorkspaceEdit: { replace: any; delete: any }
	let mockTask: any

	beforeEach(() => {
		vi.clearAllMocks()
		mockWorkspaceEdit = {
			replace: vi.fn(),
			delete: vi.fn(),
		}
		vi.mocked(vscode.WorkspaceEdit).mockImplementation(() => mockWorkspaceEdit as any)

		// Create a mock Task instance
		mockTask = {
			providerRef: {
				deref: vi.fn().mockReturnValue({
					getState: vi.fn().mockResolvedValue({
						includeDiagnosticMessages: true,
						maxDiagnosticMessages: 50,
					}),
				}),
			},
		}

		diffViewProvider = new DiffViewProvider(mockCwd, mockTask)
		// Mock the necessary properties and methods
		;(diffViewProvider as any).relPath = "test.txt"
		;(diffViewProvider as any).activeDiffEditor = {
			document: {
				uri: { fsPath: `${mockCwd}/test.txt` },
				getText: vi.fn(),
				lineCount: 10,
			},
			selection: {
				active: { line: 0, character: 0 },
				anchor: { line: 0, character: 0 },
			},
			edit: vi.fn().mockResolvedValue(true),
			revealRange: vi.fn(),
		}
		;(diffViewProvider as any).activeLineController = { setActiveLine: vi.fn(), clear: vi.fn() }
		;(diffViewProvider as any).fadedOverlayController = {
			updateOverlayAfterLine: vi.fn(),
			addLines: vi.fn(),
			clear: vi.fn(),
		}
	})

	describe("update method", () => {
		it("should preserve empty last line when original content has one", async () => {
			;(diffViewProvider as any).originalContent = "Original content\n"
			await diffViewProvider.update("New content", true)

			expect(mockWorkspaceEdit.replace).toHaveBeenCalledWith(
				expect.anything(),
				expect.anything(),
				"New content\n",
			)
		})

		it("should not add extra newline when accumulated content already ends with one", async () => {
			;(diffViewProvider as any).originalContent = "Original content\n"
			await diffViewProvider.update("New content\n", true)

			expect(mockWorkspaceEdit.replace).toHaveBeenCalledWith(
				expect.anything(),
				expect.anything(),
				"New content\n",
			)
		})

		it("should not add newline when original content does not end with one", async () => {
			;(diffViewProvider as any).originalContent = "Original content"
			await diffViewProvider.update("New content", true)

			expect(mockWorkspaceEdit.replace).toHaveBeenCalledWith(expect.anything(), expect.anything(), "New content")
		})
	})

	describe("open method", () => {
		it("should pre-open file as text document before executing diff command", async () => {
			// Setup
			const mockEditor = {
				document: {
					uri: { fsPath: `${mockCwd}/test.md`, scheme: "file" },
					getText: vi.fn().mockReturnValue(""),
					lineCount: 0,
				},
				selection: {
					active: { line: 0, character: 0 },
					anchor: { line: 0, character: 0 },
				},
				edit: vi.fn().mockResolvedValue(true),
				revealRange: vi.fn(),
			}

			// Track the order of calls
			const callOrder: string[] = []

			// Mock showTextDocument to track when it's called
			vi.mocked(vscode.window.showTextDocument).mockImplementation(async (uri, options) => {
				callOrder.push("showTextDocument")
				expect(options).toEqual({ preview: false, viewColumn: vscode.ViewColumn.Active, preserveFocus: true })
				return mockEditor as any
			})

			// Mock onDidChangeActiveTextEditor so that the diff editor "opens"
			// immediately in our test environment and resolves the promise in openDiffEditor.
			vi.mocked(vscode.window.onDidChangeActiveTextEditor).mockImplementation((callback: any) => {
				// Simulate VS Code activating the diff editor (using our mock editor)
				// Use a timeout to ensure the disposable is initialized before callback runs
				setTimeout(() => {
					callback(mockEditor as any)
				}, 0)
				return { dispose: vi.fn() }
			})

			// Mock executeCommand to track when it's called
			vi.mocked(vscode.commands.executeCommand).mockImplementation(async (command) => {
				callOrder.push("executeCommand")
				expect(command).toBe("vscode.diff")
				return undefined
			})

			// Mock workspace.onDidOpenTextDocument to trigger immediately
			vi.mocked(vscode.workspace.onDidOpenTextDocument).mockImplementation((callback) => {
				// Trigger the callback immediately with the document
				setTimeout(() => {
					callback({ uri: { fsPath: `${mockCwd}/test.md`, scheme: "file" } } as any)
				}, 0)
				return { dispose: vi.fn() }
			})

			// Mock window.visibleTextEditors to return our editor
			vi.mocked(vscode.window).visibleTextEditors = [mockEditor as any]

			// Set up for file
			;(diffViewProvider as any).editType = "modify"

			// Execute open
			await diffViewProvider.open("test.md")

			// Verify that showTextDocument was called before executeCommand
			expect(callOrder).toEqual(["showTextDocument", "executeCommand"])

			// Verify that showTextDocument was called with preview: false and preserveFocus: true
			expect(vscode.window.showTextDocument).toHaveBeenCalledWith(
				expect.objectContaining({ fsPath: `${mockCwd}/test.md` }),
				{ preview: false, viewColumn: vscode.ViewColumn.Active, preserveFocus: true },
			)

			// Verify that the diff command was executed
			expect(vscode.commands.executeCommand).toHaveBeenCalledWith(
				"vscode.diff",
				expect.any(Object),
				expect.any(Object),
				`test.md: ${DIFF_VIEW_LABEL_CHANGES} (Editable)`,
				{ preserveFocus: true },
			)
		})

		it("should handle showTextDocument failure", async () => {
			// Mock showTextDocument to fail
			vi.mocked(vscode.window.showTextDocument).mockRejectedValue(new Error("Cannot open file"))

			// Mock workspace.onDidOpenTextDocument
			vi.mocked(vscode.workspace.onDidOpenTextDocument).mockReturnValue({ dispose: vi.fn() })

			// Mock window.onDidChangeVisibleTextEditors
			vi.mocked(vscode.window.onDidChangeVisibleTextEditors).mockReturnValue({ dispose: vi.fn() })

			// Set up for file
			;(diffViewProvider as any).editType = "modify"

			// Try to open and expect rejection
			await expect(diffViewProvider.open("test.md")).rejects.toThrow(
				"Failed to execute diff command for /mock/cwd/test.md: Cannot open file",
			)
		})
	})

	describe("closeAllDiffViews method", () => {
		it("should close diff views including those identified by label", async () => {
			// Mock tab groups with various types of tabs
			const mockTabs = [
				// Normal diff view
				{
					input: {
						constructor: { name: "TabInputTextDiff" },
						original: { scheme: DIFF_VIEW_URI_SCHEME },
						modified: { fsPath: "/test/file1.ts" },
					},
					label: `file1.ts: ${DIFF_VIEW_LABEL_CHANGES} (Editable)`,
					isDirty: false,
				},
				// Diff view identified by label (for pre-opened files)
				{
					input: {
						constructor: { name: "TabInputTextDiff" },
						original: { scheme: "file" }, // Different scheme due to pre-opening
						modified: { fsPath: "/test/file2.md" },
					},
					label: `file2.md: ${DIFF_VIEW_LABEL_CHANGES} (Editable)`,
					isDirty: false,
				},
				// Regular file tab (should not be closed)
				{
					input: {
						constructor: { name: "TabInputText" },
						uri: { fsPath: "/test/file3.js" },
					},
					label: "file3.js",
					isDirty: false,
				},
				// Dirty diff view (should not be closed)
				{
					input: {
						constructor: { name: "TabInputTextDiff" },
						original: { scheme: DIFF_VIEW_URI_SCHEME },
						modified: { fsPath: "/test/file4.ts" },
					},
					label: `file4.ts: ${DIFF_VIEW_LABEL_CHANGES} (Editable)`,
					isDirty: true,
				},
			]

			// Make tabs appear as TabInputTextDiff instances
			mockTabs.forEach((tab) => {
				if (tab.input.constructor.name === "TabInputTextDiff") {
					Object.setPrototypeOf(tab.input, vscode.TabInputTextDiff.prototype)
				}
			})

			// Mock the tabGroups getter
			Object.defineProperty(vscode.window.tabGroups, "all", {
				get: () => [
					{
						tabs: mockTabs as any,
					},
				],
				configurable: true,
			})

			const closedTabs: any[] = []
			vi.mocked(vscode.window.tabGroups.close).mockImplementation((tab) => {
				closedTabs.push(tab)
				return Promise.resolve(true)
			})

			// Execute closeAllDiffViews
			await (diffViewProvider as any).closeAllDiffViews()

			// Verify that only the appropriate tabs were closed
			expect(closedTabs).toHaveLength(2)
			expect(closedTabs[0].label).toBe(`file1.ts: ${DIFF_VIEW_LABEL_CHANGES} (Editable)`)
			expect(closedTabs[1].label).toBe(`file2.md: ${DIFF_VIEW_LABEL_CHANGES} (Editable)`)

			// Verify that the regular file and dirty diff were not closed
			expect(closedTabs.find((t) => t.label === "file3.js")).toBeUndefined()
			expect(
				closedTabs.find((t) => t.label === `file4.ts: ${DIFF_VIEW_LABEL_CHANGES} (Editable)` && t.isDirty),
			).toBeUndefined()
		})
	})

	describe("saveDirectly method", () => {
		beforeEach(() => {
			// Mock vscode functions
			vi.mocked(vscode.window.showTextDocument).mockResolvedValue({} as any)
			vi.mocked(vscode.languages.getDiagnostics).mockReturnValue([])
		})

		it("should write content directly to file without opening diff view", async () => {
			const mockDelay = vi.mocked(delay)
			mockDelay.mockClear()

			const result = await diffViewProvider.saveDirectly("test.ts", "new content", true, true, 2000)

			// Verify file was written
			const fs = await import("fs/promises")
			expect(fs.writeFile).toHaveBeenCalledWith(`${mockCwd}/test.ts`, "new content", "utf-8")

			// Verify file was opened without focus
			expect(vscode.window.showTextDocument).toHaveBeenCalledWith(
				expect.objectContaining({ fsPath: `${mockCwd}/test.ts` }),
				{ preview: false, preserveFocus: true },
			)

			// Verify diagnostics were checked after delay
			expect(mockDelay).toHaveBeenCalledWith(2000)
			expect(vscode.languages.getDiagnostics).toHaveBeenCalled()

			// Verify result
			expect(result.newProblemsMessage).toBe("")
			expect(result.userEdits).toBeUndefined()
			expect(result.finalContent).toBe("new content")
		})

		it("should not open file when openWithoutFocus is false", async () => {
			await diffViewProvider.saveDirectly("test.ts", "new content", false, true, 1000)

			// Verify file was written
			const fs = await import("fs/promises")
			expect(fs.writeFile).toHaveBeenCalledWith(`${mockCwd}/test.ts`, "new content", "utf-8")

			// Verify file was NOT opened
			expect(vscode.window.showTextDocument).not.toHaveBeenCalled()
		})

		it("should skip diagnostics when diagnosticsEnabled is false", async () => {
			const mockDelay = vi.mocked(delay)
			mockDelay.mockClear()
			vi.mocked(vscode.languages.getDiagnostics).mockClear()

			await diffViewProvider.saveDirectly("test.ts", "new content", true, false, 1000)

			// Verify file was written
			const fs = await import("fs/promises")
			expect(fs.writeFile).toHaveBeenCalledWith(`${mockCwd}/test.ts`, "new content", "utf-8")

			// Verify delay was NOT called
			expect(mockDelay).not.toHaveBeenCalled()
			// getDiagnostics is called once for pre-diagnostics, but not for post-diagnostics
			expect(vscode.languages.getDiagnostics).toHaveBeenCalledTimes(1)
		})

		it("should handle negative delay values", async () => {
			const mockDelay = vi.mocked(delay)
			mockDelay.mockClear()

			await diffViewProvider.saveDirectly("test.ts", "new content", true, true, -500)

			// Verify delay was called with 0 (safe minimum)
			expect(mockDelay).toHaveBeenCalledWith(0)
		})

		it("should store results for formatFileWriteResponse", async () => {
			await diffViewProvider.saveDirectly("test.ts", "new content", true, true, 1000)

			// Verify internal state was updated
			expect((diffViewProvider as any).newProblemsMessage).toBe("")
			expect((diffViewProvider as any).userEdits).toBeUndefined()
			expect((diffViewProvider as any).relPath).toBe("test.ts")
			expect((diffViewProvider as any).newContent).toBe("new content")
		})
	})

	describe("saveChanges method with diagnostic settings", () => {
		beforeEach(() => {
			// Setup common mocks for saveChanges tests
			;(diffViewProvider as any).relPath = "test.ts"
			;(diffViewProvider as any).newContent = "new content"
			;(diffViewProvider as any).activeDiffEditor = {
				document: {
					getText: vi.fn().mockReturnValue("new content"),
					isDirty: false,
					save: vi.fn().mockResolvedValue(undefined),
				},
			}
			;(diffViewProvider as any).preDiagnostics = []

			// Mock vscode functions
			vi.mocked(vscode.window.showTextDocument).mockResolvedValue({} as any)
			vi.mocked(vscode.languages.getDiagnostics).mockReturnValue([])
		})

		it("should apply diagnostic delay when diagnosticsEnabled is true", async () => {
			const mockDelay = vi.mocked(delay)
			mockDelay.mockClear()

			// Mock closeAllDiffViews
			;(diffViewProvider as any).closeAllDiffViews = vi.fn().mockResolvedValue(undefined)

			const result = await diffViewProvider.saveChanges(true, 3000)

			// Verify delay was called with correct duration
			expect(mockDelay).toHaveBeenCalledWith(3000)
			expect(vscode.languages.getDiagnostics).toHaveBeenCalled()
			expect(result.newProblemsMessage).toBe("")
		})

		it("should skip diagnostics when diagnosticsEnabled is false", async () => {
			const mockDelay = vi.mocked(delay)
			mockDelay.mockClear()

			// Mock closeAllDiffViews
			;(diffViewProvider as any).closeAllDiffViews = vi.fn().mockResolvedValue(undefined)

			const result = await diffViewProvider.saveChanges(false, 2000)

			// Verify delay was NOT called and diagnostics were NOT checked
			expect(mockDelay).not.toHaveBeenCalled()
			expect(vscode.languages.getDiagnostics).not.toHaveBeenCalled()
			expect(result.newProblemsMessage).toBe("")
		})

		it("should use default values when no parameters provided", async () => {
			const mockDelay = vi.mocked(delay)
			mockDelay.mockClear()

			// Mock closeAllDiffViews
			;(diffViewProvider as any).closeAllDiffViews = vi.fn().mockResolvedValue(undefined)

			const result = await diffViewProvider.saveChanges()

			// Verify default behavior (enabled=true, delay=2000ms)
			expect(mockDelay).toHaveBeenCalledWith(1000)
			expect(vscode.languages.getDiagnostics).toHaveBeenCalled()
			expect(result.newProblemsMessage).toBe("")
		})

		it("should handle custom delay values", async () => {
			const mockDelay = vi.mocked(delay)
			mockDelay.mockClear()

			// Mock closeAllDiffViews
			;(diffViewProvider as any).closeAllDiffViews = vi.fn().mockResolvedValue(undefined)

			const result = await diffViewProvider.saveChanges(true, 5000)

			// Verify custom delay was used
			expect(mockDelay).toHaveBeenCalledWith(5000)
			expect(vscode.languages.getDiagnostics).toHaveBeenCalled()
		})
	})
})