import Foundation

@main
struct ExpenseTemplateTests {
    static func rejects(_ action: () throws -> Void) {
        do {
            try action()
            preconditionFailure("Unexpected success")
        } catch {
            precondition(!error.localizedDescription.isEmpty)
        }
    }

    static func main() throws {
        let root = FileManager.default.temporaryDirectory.appendingPathComponent(UUID().uuidString)
        try FileManager.default.createDirectory(at: root, withIntermediateDirectories: true)
        defer { try? FileManager.default.removeItem(at: root) }
        let source = root.appendingPathComponent("原模板.xlsx")
        let data = Data("Synthetic template fixture".utf8)
        try data.write(to: source)
        let storage = ExpenseTemplateStorage(root: root)
        let initial = try storage.load()
        precondition(initial == nil)
        let mapping = ExpenseTemplateMapping(sheetName: "组 A", startRow: 5, endRow: 10,
                                             columns: ["purpose": "B", "amount": "F"], cells: ["recipient": "B12"])
        let validation = ExpenseTemplateValidation(templateVersion: "mapped-xlsx-v1",
                                                   fingerprint: ExpenseTemplateStorage.fingerprint(data),
                                                   mapping: mapping, mappingDigest: "test-mapping-digest")
        let saved = try storage.save(name: source.lastPathComponent, source: source, validation: validation)
        let reloadedStorage = ExpenseTemplateStorage(root: root)
        let reloaded = try reloadedStorage.load()!
        precondition(reloaded.mapping == mapping)
        precondition(reloaded.name == "原模板.xlsx")
        let reloadedData = try Data(contentsOf: reloadedStorage.file(for: reloaded))
        precondition(reloadedData == data)
        let workspace = root.appendingPathComponent("workspace.json")
        try Data("current expense data".utf8).write(to: workspace)
        try Data("{}".utf8).write(to: workspace, options: .atomic)
        let afterWorkspaceClear = try reloadedStorage.load()
        precondition(afterWorkspaceClear?.fingerprint == saved.fingerprint)
        let next = try storage.save(name: "新模板.xlsx", source: source, validation: validation)
        precondition(!FileManager.default.fileExists(atPath: storage.directory.appendingPathComponent(saved.fileName).path))
        precondition(next.fileName != saved.fileName)
        var bad = validation
        bad.fingerprint = "wrong"
        rejects { _ = try storage.save(name: "invalid", source: source, validation: bad) }
        let afterFailedSave = try storage.load()
        precondition(afterFailedSave?.fileName == next.fileName)
        var traversal = next
        traversal.fileName = "../原模板.xlsx"
        rejects { _ = try storage.file(for: traversal) }
        let result = try JSONSerialization.data(withJSONObject: [
            "templateVersion": "mapped-xlsx-v1", "templateFingerprint": saved.fingerprint,
            "templateMappingDigest": saved.mappingDigest
        ])
        try ExpenseTemplateStorage.validateExport(result, template: saved)
        rejects { try ExpenseTemplateStorage.validateExport(Data("{}".utf8), template: saved) }
        var differentMapping = saved
        differentMapping.mappingDigest = "different"
        rejects { try ExpenseTemplateStorage.validateExport(result, template: differentMapping) }
        let storedFile = try storage.file(for: next)
        try Data("changed".utf8).write(to: storedFile)
        rejects { _ = try storage.file(for: next) }
        try storage.remove()
        let afterRemoval = try storage.load()
        precondition(afterRemoval == nil)
        precondition(!FileManager.default.fileExists(atPath: storage.directory.path))
        let originalData = try Data(contentsOf: source)
        precondition(originalData == data)
        precondition(FileManager.default.fileExists(atPath: workspace.path))
        try storage.remove()
        print("Template persistence, replacement, reset isolation and export fingerprint tests passed")
    }
}