format

type AlignedStatement struct {
	// Source is the original source line text.
	Source string

	// Result is the raw, unformatted evaluation result.
	// Nil if this line has no result (blank, result-comment, etc.).
	Result types.Type

	// Variable is the name assigned by this statement (e.g., "x" from "x = 10").
	// Empty for anonymous expressions.
	Variable string

	// IsBlank is true for empty/whitespace-only source lines.
	IsBlank bool

	// IsResultLine is true for previous result comments (e.g., "# = 42", "→ 42").
	// Formatters should typically skip these.
	IsResultLine bool
}

type CalcMarkFormatter struct{}

type Formatter interface {
	// Format writes the formatted document to the writer
	Format(w io.Writer, doc *document.Document, opts Options) error

	// Extensions returns file extensions this formatter handles
	Extensions() []string
}

type HTMLFormatter struct{}

type JSONBlock struct {
	Type               string           `json:"type"`
	Source             []string         `json:"source"`
	InterpolatedSource []string         `json:"interpolated_source,omitempty"`
	Results            []JSONResult     `json:"results,omitempty"`
	Error              string           `json:"error,omitempty"`
	Diagnostics        []JSONDiagnostic `json:"diagnostics,omitempty"`
	HTML               string           `json:"html,omitempty"`
}

type JSONConvertTo struct {
	System         string   `json:"system"`
	UnitCategories []string `json:"unit_categories,omitempty"`
}

type JSONDiagnostic struct {
	Severity string `json:"severity"`
	Code     string `json:"code,omitempty"`
	Message  string `json:"message"`
	Line     int    `json:"line,omitempty"`
	Column   int    `json:"column,omitempty"`
}

type JSONDocument struct {
	Frontmatter *JSONFrontmatter `json:"frontmatter,omitempty"`
	Blocks      []JSONBlock      `json:"blocks"`
}

type JSONFormatter struct{}

type JSONFrontmatter struct {
	Globals   map[string]string `json:"globals,omitempty"`
	Exchange  map[string]string `json:"exchange,omitempty"`
	Scale     *JSONScale        `json:"scale,omitempty"`
	ConvertTo *JSONConvertTo    `json:"convert_to,omitempty"`
}

type JSONResult struct {
	Source        string   `json:"source"`
	Value         string   `json:"value,omitempty"`
	Type          string   `json:"type,omitempty"`
	NumericValue  *float64 `json:"numeric_value,omitempty"`
	Numerator     *int64   `json:"numerator,omitempty"`
	Denominator   *int64   `json:"denominator,omitempty"`
	Unit          string   `json:"unit,omitempty"`
	DateValue     string   `json:"date_value,omitempty"`
	IsApproximate bool     `json:"is_approximate,omitempty"`
	IsExplicit    bool     `json:"is_explicit,omitempty"`
	Error         string   `json:"error,omitempty"`
	Variable      string   `json:"variable,omitempty"`
}

type JSONScale struct {
	Factor         float64  `json:"factor"`
	UnitCategories []string `json:"unit_categories,omitempty"`
}

type MarkdownFormatter struct{}

type Options struct {
	Verbose       bool   // Show calculation steps, types, units
	IncludeErrors bool   // Include error details
	Template      string // For template-based formatters (future use)

	// DisplayFormatter is the locale-aware formatter for rendering values.
	// When zero-value, formatters fall back to display.Format() (en-US default).
	DisplayFormatter display.Formatter

	// FrontmatterAsCodeFence renders CalcMark frontmatter as a “`yaml code
	// fence instead of raw --- delimiters. Use when embedding CalcMark output
	// inside a Hugo page that has its own YAML frontmatter.
	FrontmatterAsCodeFence bool

	// SuppressFrontmatter skips frontmatter serialization (used by embedded mode).
	SuppressFrontmatter bool
}

type TemplateBlock struct {
	Type              string
	SourceLines       []TemplateLine // For calc blocks with per-line results
	Error             string
	HasLineDiagnostic bool          // True if any SourceLine has a per-line Error
	Warnings          []string      // Diagnostic warnings (e.g., reserved keyword as variable name)
	HTML              template.HTML // For text blocks
	DocLine           int           // 1-indexed document-absolute start line (for scroll sync)
}

type TemplateExchange struct {
	From string
	To   string
	Rate string
}

type TemplateExtra struct {
	Key   string
	Value string // formatted for display
}

type TemplateFrontmatter struct {
	Globals          []TemplateGlobal
	Exchange         []TemplateExchange
	Scale            string // e.g. "2x" or "0.5x [Length, Mass]"
	ConvertTo        string // e.g. "imperial" or "si [Length]"
	FiscalYearStarts string // e.g. "July" or "July 15"
	Extra            []TemplateExtra
}

type TemplateGlobal struct {
	Name  string
	Value string
}

type TemplateLine struct {
	Source      string
	Result      string // Formatted result for this line
	Error       string // Error message for this line (empty if successful)
	IsCascading bool   // True if this is a cascading error (hint severity)
	DocLine     int    // 1-indexed document-absolute line number (for scroll sync)
}

type TextFormatter struct{}