class Phlex::CSV

# File lib/phlex/csv.rb, line 12
def initialize(collection)
        @collection = collection
        @_row_buffer = []
        @_headers = []
        @_row_appender = nil
end

# File lib/phlex/csv.rb, line 125
def around_row(...)
        row_template(...)
        @row_appender.call
end

# File lib/phlex/csv.rb, line 21
        def call(buffer = +"", context: nil, delimiter: self.delimiter)
                ensure_escape_csv_injection_configured!

                strip_whitespace = trim_whitespace?
                escape_csv_injection = escape_csv_injection?
                row_buffer = @_row_buffer
                headers = @_headers
                has_yielder = respond_to?(:yielder, true)
                first_row = true
                render_headers = render_headers?

                if delimiter.length != 1
                        raise Phlex::ArgumentError.new("Delimiter must be a single character")
                end

                if strip_whitespace
                        escape_regex = /[\n"#{delimiter}]/
                else
                        escape_regex = /^\s|\s$|[\n"#{delimiter}]/
                end

                if has_yielder
                        warn <<~MESSAGE
                                Custom yielders are deprecated in Phlex::CSV.

                                Please replace your yielder with an `around_row` method.

                                You should be able to just rename your yielder method
                                and change `yield` to `super`.
                        MESSAGE
                end

                row_appender = -> {
                        row = row_buffer

                        if first_row
                                first_row = false

                                i = 0
                                number_of_columns = row.length
                                first_col = true

                                while i < number_of_columns
                                        header, = row[i]
                                        headers[i] = header

                                        if render_headers
                                                if first_col
                                                        first_col = false
                                                else
                                                        buffer << delimiter
                                                end

                                                __escape__(buffer, header, escape_csv_injection:, strip_whitespace:, escape_regex:)
                                        end
                                        i += 1
                                end

                                buffer << "\n" if render_headers
                        end

                        i = 0
                        number_of_columns = row.length
                        first_col = true

                        while i < number_of_columns
                                header, value = row[i]

                                unless headers[i] == header
                                        raise Phlex::RuntimeError.new("Header mismatch at index #{i}: expected #{headers[i]}, got #{header}.")
                                end

                                if first_col
                                        first_col = false
                                else
                                        buffer << delimiter
                                end

                                __escape__(buffer, value, escape_csv_injection:, strip_whitespace:, escape_regex:)
                                i += 1
                        end

                        buffer << "\n"

                        row_buffer.clear
                }

                if has_yielder
                        each_item do |record|
                                yielder(record) do |*a, **k|
                                        row_template(*a, **k)
                                        row_appender.call
                                end
                        end
                else
                        @row_appender = row_appender
                        each_item do |record|
                                around_row(record)
                        end
                end

                buffer
        end

# File lib/phlex/csv.rb, line 134
def content_type
        "text/csv"
end

# File lib/phlex/csv.rb, line 138
def delimiter
        ","
end

# File lib/phlex/csv.rb, line 130
def filename
        nil
end

# File lib/phlex/csv.rb, line 165
        def __escape__(buffer, value, escape_csv_injection:, strip_whitespace:, escape_regex:)
        value = case value
        when String
                value
        when Symbol
                value.name
        else
                value.to_s
        end

        if strip_whitespace
                value = value.strip

                if escape_csv_injection
                        if value.empty?
                                buffer << value
                        elsif FORMULA_PREFIXES_MAP[value.getbyte(0)]
                                value.gsub!('"', '""')
                                buffer << '"\'' << value << '"'
                        elsif value.match?(escape_regex)
                                value.gsub!('"', '""')
                                buffer << '"' << value << '"'
                        else
                                buffer << value
                        end
                else # not escaping CSV injection
                        buffer << value
                end
        else # not stripping whitespace
                if escape_csv_injection
                        first_byte = value.getbyte(0)

                        if value.empty?
                                buffer << '""'
                        elsif FORMULA_PREFIXES_MAP[first_byte]
                                buffer << '"\'' << value.gsub('"', '""') << '"'
                        elsif value.match?(escape_regex)
                                buffer << '"' << value.gsub('"', '""') << '"'
                        else
                                buffer << value
                        end
                else # not escaping CSV injection
                        if value.empty?
                                buffer << '""'
                        elsif value.match?(escape_regex)
                                buffer << '"' << value.gsub('"', '""') << '"'
                        else
                                buffer << value
                        end
                end
        end
end

# File lib/phlex/csv.rb, line 142
        def column(header = nil, value)
        @_row_buffer << [header, value]
end

# File lib/phlex/csv.rb, line 146
        def each_item(&)
        collection.each(&)
end

# File lib/phlex/csv.rb, line 234
                def ensure_escape_csv_injection_configured!
                if escape_csv_injection? == UNDEFINED
                        raise <<~MESSAGE
                                You need to define `escape_csv_injection?` in #{self.class.name}.

                                CSV injection is a security vulnerability where malicious spreadsheet
                                formulae are used to execute code or exfiltrate data when a CSV is opened
                                in a spreadsheet program such as Microsoft Excel or Google Sheets.

                                For more information, see https://owasp.org/www-community/attacks/CSV_Injection

                                If you’re sure this CSV will never be opened in a spreadsheet program,
                                you can *disable* CSV injection escapes:

                                  def escape_csv_injection? = false

                                This is useful when using CSVs for byte-for-byte data exchange between secure systems.

                                Alternatively, you can *enable* CSV injection escapes at the cost of data integrity:

                                  def escape_csv_injection? = true

                                Enabling the CSV injection escapes will prefix with a single quote `'` any
                                values that start with: `=`, `+`, `-`, `@`, `\\t`, `\\r`

                                Unfortunately, there is no one-size-fits-all solution to CSV injection.

                                You need to decide based on your specific use case.
                        MESSAGE
                end
        end

# File lib/phlex/csv.rb, line 161
        def escape_csv_injection?
        UNDEFINED
end

# File lib/phlex/csv.rb, line 224
        def method_missing(method_name, ...)
        if method_name == :row_template && respond_to?(:view_template)
                warn "Deprecated: Use `row_template` instead of `view_template` in Phlex CSVs."
                self.class.alias_method :row_template, :view_template
                view_template(...)
        else
                super
        end
end

# File lib/phlex/csv.rb, line 151
        def render_headers?
        true
end

# File lib/phlex/csv.rb, line 219
        def respond_to_missing?(method_name, include_private)
        (method_name == :row_template && respond_to?(:view_template)) || super
end

# File lib/phlex/csv.rb, line 156
        def trim_whitespace?
        false
end