import XCTest
@testable import AIStudyApp

final class MaterialPathResolverTests: XCTestCase {

    // MARK: - resolveKnowledgeSource path

    func test_resolveKnowledgeSource_finds_file_in_knowledge_sources_dir() {
        let docs = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
        let sourceId = "ks-test-\(UUID().uuidString)"
        let ksDir = docs.appendingPathComponent("knowledge_sources/\(sourceId)")
        try? FileManager.default.createDirectory(at: ksDir, withIntermediateDirectories: true)
        let fileURL = ksDir.appendingPathComponent("content.md")
        defer {
            try? FileManager.default.removeItem(at: fileURL)
            try? FileManager.default.removeItem(at: ksDir)
        }

        FileManager.default.createFile(atPath: fileURL.path, contents: "test".data(using: .utf8))

        let result = MaterialPathResolver.resolve(materialId: sourceId, apiType: "knowledge_source", title: "content.md")
        XCTAssertNotNil(result)
        XCTAssertEqual(result?.filePath, fileURL.path)
        XCTAssertEqual(result?.materialType, .markdown)
    }

    func test_resolveKnowledgeSource_returns_nil_for_empty_dir() {
        let docs = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
        let sourceId = "ks-empty-\(UUID().uuidString)"
        let ksDir = docs.appendingPathComponent("knowledge_sources/\(sourceId)")
        try? FileManager.default.createDirectory(at: ksDir, withIntermediateDirectories: true)
        defer { try? FileManager.default.removeItem(at: ksDir) }

        // Empty directory → no files → falls through to Documents/Caches
        let result = MaterialPathResolver.resolve(materialId: sourceId, apiType: "knowledge_source", title: "note.md")
        // Directory exists but is empty → resolveKnowledgeSource returns nil → falls through
        XCTAssertNil(result) // No file in Documents or Caches either
    }

    // MARK: - resolve returns nil for nonexistent file

    func test_resolve_returns_nil_for_nonexistent_material() {
        let result = MaterialPathResolver.resolve(
            materialId: UUID().uuidString,
            apiType: nil,
            title: nil
        )
        XCTAssertNil(result)
    }

    // MARK: - resolve finds file in Documents

    func test_resolve_finds_file_in_documents() {
        let docs = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
        let fileId = "test-docs-\(UUID().uuidString)"
        let fileURL = docs.appendingPathComponent(fileId)
        defer { try? FileManager.default.removeItem(at: fileURL) }
        FileManager.default.createFile(atPath: fileURL.path, contents: "test".data(using: .utf8))

        let result = MaterialPathResolver.resolve(materialId: fileId, apiType: nil, title: nil)
        XCTAssertNotNil(result)
        XCTAssertEqual(result?.filePath, fileURL.path)
    }

    // MARK: - resolve finds file in Caches

    func test_resolve_finds_file_in_caches() {
        let cache = FileManager.default.urls(for: .cachesDirectory, in: .userDomainMask).first!
        let fileId = "test-cache-\(UUID().uuidString)"
        let fileURL = cache.appendingPathComponent(fileId)
        defer { try? FileManager.default.removeItem(at: fileURL) }
        FileManager.default.createFile(atPath: fileURL.path, contents: "test".data(using: .utf8))

        let result = MaterialPathResolver.resolve(materialId: fileId, apiType: nil, title: nil)
        XCTAssertNotNil(result)
        XCTAssertEqual(result?.filePath, fileURL.path)
    }

    // MARK: - materialType inference from title extension

    func test_resolve_infers_markdown_from_title() {
        let docs = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
        let fileId = "test-md-\(UUID().uuidString)"
        let fileURL = docs.appendingPathComponent(fileId)
        defer { try? FileManager.default.removeItem(at: fileURL) }
        FileManager.default.createFile(atPath: fileURL.path, contents: "test".data(using: .utf8))

        let result = MaterialPathResolver.resolve(materialId: fileId, apiType: "temporary_file", title: "note.md")
        XCTAssertNotNil(result)
        XCTAssertEqual(result?.materialType, .markdown)
    }

    func test_resolve_infers_pdf_from_title() {
        let docs = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
        let fileId = "test-pdf-\(UUID().uuidString)"
        let fileURL = docs.appendingPathComponent(fileId)
        defer { try? FileManager.default.removeItem(at: fileURL) }
        FileManager.default.createFile(atPath: fileURL.path, contents: "test".data(using: .utf8))

        let result = MaterialPathResolver.resolve(materialId: fileId, apiType: "temporary_file", title: "book.pdf")
        XCTAssertNotNil(result)
        XCTAssertEqual(result?.materialType, .pdf)
    }

    func test_resolve_infers_text_from_title() {
        let docs = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
        let fileId = "test-txt-\(UUID().uuidString)"
        let fileURL = docs.appendingPathComponent(fileId)
        defer { try? FileManager.default.removeItem(at: fileURL) }
        FileManager.default.createFile(atPath: fileURL.path, contents: "test".data(using: .utf8))

        let result = MaterialPathResolver.resolve(materialId: fileId, apiType: "knowledge_source", title: "notes.txt")
        XCTAssertNotNil(result)
        XCTAssertEqual(result?.materialType, .text)
    }

    func test_resolve_infers_epub_from_title() {
        let docs = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
        let fileId = "test-epub-\(UUID().uuidString)"
        let fileURL = docs.appendingPathComponent(fileId)
        defer { try? FileManager.default.removeItem(at: fileURL) }
        FileManager.default.createFile(atPath: fileURL.path, contents: "test".data(using: .utf8))

        let result = MaterialPathResolver.resolve(materialId: fileId, apiType: "temporary_file", title: "book.epub")
        XCTAssertNotNil(result)
        XCTAssertEqual(result?.materialType, .epub)
    }

    func test_resolve_infers_image_from_title() {
        let docs = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
        let fileId = "test-img-\(UUID().uuidString)"
        let fileURL = docs.appendingPathComponent(fileId)
        defer { try? FileManager.default.removeItem(at: fileURL) }
        FileManager.default.createFile(atPath: fileURL.path, contents: "test".data(using: .utf8))

        for ext in ["png", "jpg", "jpeg", "webp"] {
            let r = MaterialPathResolver.resolve(materialId: fileId, apiType: "knowledge_source", title: "photo.\(ext)")
            XCTAssertNotNil(r)
            XCTAssertEqual(r?.materialType, .image, "ext .\(ext) should infer .image")
        }
    }

    func test_resolve_unknown_apiType_defaults_to_unknown() {
        let docs = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
        let fileId = "test-unk-\(UUID().uuidString)"
        let fileURL = docs.appendingPathComponent(fileId)
        defer { try? FileManager.default.removeItem(at: fileURL) }
        FileManager.default.createFile(atPath: fileURL.path, contents: "test".data(using: .utf8))

        let result = MaterialPathResolver.resolve(materialId: fileId, apiType: "other_type", title: "file.bin")
        XCTAssertNotNil(result)
        XCTAssertEqual(result?.materialType, .unknown)
    }
}