feat: initial release v0.3.0

- Support 9 chart types: line, bar, pie, scatter, bubble, donut, mixed, polar, radar
- Multi-format output: ANSI, SVG, PNG, Markdown
- Go + Fiber + gonum/plot
- Docker support
- Morandi color palette

internal/renderer/text.go

@@ -0,0 +1,198 @@
+package renderer
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/picoclaw/chart/internal/types"
+)
+
+type TextRenderer struct {
+	width  int
+	height int
+}
+
+func NewTextRenderer() *TextRenderer {
+	return &TextRenderer{
+		width:  60,
+		height: 15,
+	}
+}
+
+func (r *TextRenderer) Render(chart *types.Chart) ([]byte, error) {
+	var sb strings.Builder
+
+	if chart.Title != "" {
+		sb.WriteString(fmt.Sprintf("[ Chart: %s ]\n", chart.Title))
+	}
+
+	if len(chart.Data.Datasets) == 0 {
+		sb.WriteString("No data available.\n")
+		return []byte(sb.String()), nil
+	}
+
+	switch chart.Type {
+	case types.ChartTypePie, types.ChartTypeDonut:
+		r.renderPieChart(&sb, &chart.Data)
+	case types.ChartTypeBubble:
+		r.renderBubbleChart(&sb, &chart.Data)
+	case types.ChartTypeMixed:
+		r.renderMixedChart(&sb, &chart.Data)
+	case types.ChartTypePolar, types.ChartTypeRadar:
+		r.renderRadarLikeChart(&sb, &chart.Data)
+	default:
+		r.renderBarLikeChart(&sb, &chart.Data)
+	}
+
+	return []byte(sb.String()), nil
+}
+
+func (r *TextRenderer) renderPieChart(sb *strings.Builder, data *types.ChartData) {
+	dataset := data.Datasets[0]
+	values := dataset.Values
+	labels := data.Labels
+
+	total := 0.0
+	for _, v := range values {
+		total += v
+	}
+
+	for i, v := range values {
+		label := fmt.Sprintf("Item %d", i+1)
+		if i < len(labels) {
+			label = labels[i]
+		}
+
+		percentage := v / total * 100
+
+		barLen := int(percentage / 4)
+		if barLen > 12 {
+			barLen = 12
+		}
+		bar := strings.Repeat("#", barLen)
+
+		sb.WriteString(fmt.Sprintf("%-12s |%s [%.1f%%]\n", label, bar, percentage))
+	}
+}
+
+func (r *TextRenderer) renderBubbleChart(sb *strings.Builder, data *types.ChartData) {
+	dataset := data.Datasets[0]
+	labels := data.Labels
+	if len(labels) == 0 {
+		labels = make([]string, len(dataset.Values))
+		for i := range labels {
+			labels[i] = fmt.Sprintf("X%d", i+1)
+		}
+	}
+
+	maxValue := dataset.Values[0]
+	for _, v := range dataset.Values {
+		if v > maxValue {
+			maxValue = v
+		}
+	}
+
+	for i, value := range dataset.Values {
+		label := labels[i]
+		bubbleSize := 2 + int((value/maxValue)*5)
+
+		bubble := strings.Repeat("o", bubbleSize)
+
+		sb.WriteString(fmt.Sprintf("%-8s |%s %.2f\n", label, bubble, value))
+	}
+}
+
+func (r *TextRenderer) renderMixedChart(sb *strings.Builder, data *types.ChartData) {
+	dataset := data.Datasets[0]
+	labels := data.Labels
+	if len(labels) == 0 {
+		labels = make([]string, len(dataset.Values))
+		for i := range labels {
+			labels[i] = fmt.Sprintf("X%d", i+1)
+		}
+	}
+
+	maxValue := dataset.Values[0]
+	for _, v := range dataset.Values {
+		if v > maxValue {
+			maxValue = v
+		}
+	}
+
+	for i, value := range dataset.Values {
+		label := labels[i]
+
+		barLen := int((value / maxValue) * float64(r.width-20))
+		if barLen < 1 {
+			barLen = 1
+		}
+
+		bar := strings.Repeat("#", barLen)
+
+		sb.WriteString(fmt.Sprintf("%-8s |%s %.2f [mixed]\n", label, bar, value))
+	}
+}
+
+func (r *TextRenderer) renderRadarLikeChart(sb *strings.Builder, data *types.ChartData) {
+	dataset := data.Datasets[0]
+	values := dataset.Values
+	labels := data.Labels
+
+	maxValue := values[0]
+	for _, v := range values {
+		if v > maxValue {
+			maxValue = v
+		}
+	}
+
+	sb.WriteString(fmt.Sprintf("[ Radar/Polar Chart: %d dimensions ]\n", len(values)))
+
+	for i, v := range values {
+		label := fmt.Sprintf("Dim %d", i+1)
+		if i < len(labels) {
+			label = labels[i]
+		}
+
+		barLen := int((v / maxValue) * float64(r.width-25))
+		if barLen < 1 {
+			barLen = 1
+		}
+
+		bar := strings.Repeat("#", barLen)
+
+		sb.WriteString(fmt.Sprintf("%-12s |%s %.2f\n", label, bar, v))
+	}
+}
+
+func (r *TextRenderer) renderBarLikeChart(sb *strings.Builder, data *types.ChartData) {
+	dataset := data.Datasets[0]
+	labels := data.Labels
+	if len(labels) == 0 {
+		labels = make([]string, len(dataset.Values))
+		for i := range labels {
+			labels[i] = fmt.Sprintf("X%d", i+1)
+		}
+	}
+
+	maxValue := dataset.Values[0]
+	for _, v := range dataset.Values {
+		if v > maxValue {
+			maxValue = v
+		}
+	}
+
+	for i, value := range dataset.Values {
+		label := labels[i]
+		if i >= len(labels) {
+			label = fmt.Sprintf("X%d", i+1)
+		}
+
+		barLen := int((value / maxValue) * float64(r.width-20))
+		if barLen < 1 {
+			barLen = 1
+		}
+
+		bar := strings.Repeat("#", barLen)
+		sb.WriteString(fmt.Sprintf("%-8s |%s %.2f\n", label, bar, value))
+	}
+}