package gsp

import (
	"fmt"
	"sort"
	"strings"
)

func (p PackResult) Markdown() string {
	var builder strings.Builder
	builder.WriteString("# GSP Context Pack\n\n")
	builder.WriteString(fmt.Sprintf("- Entry: `%s`\n", p.Entry))
	if p.Intent != "" {
		builder.WriteString(fmt.Sprintf("- Intent: `%s`\n", p.Intent))
	}
	if p.Stage != "" {
		builder.WriteString(fmt.Sprintf("- Stage: `%s`\n", p.Stage))
	}
	builder.WriteString(fmt.Sprintf("- Units: `%d`\n", p.Summary.UnitCount))
	if p.Summary.LinkCount > 0 {
		builder.WriteString(fmt.Sprintf("- Links: `%d`\n", p.Summary.LinkCount))
	}
	if p.Summary.MinResolution != "" {
		builder.WriteString(fmt.Sprintf("- Resolution: `%s` to `%s`\n", p.Summary.MinResolution, p.Summary.MaxResolution))
	}
	if p.Budget > 0 {
		builder.WriteString(fmt.Sprintf("- Budget: `%d`\n", p.Budget))
		builder.WriteString(fmt.Sprintf("- Approx chars: `%d`\n", p.ApproxChars))
		builder.WriteString(fmt.Sprintf("- Truncated: `%v`\n", p.Truncated))
	}
	builder.WriteString("\n## Units\n\n")
	for _, unit := range p.Units {
		builder.WriteString(fmt.Sprintf("### %s\n\n", unit.DisplayTitle()))
		builder.WriteString(fmt.Sprintf("- id: `%s`\n", unit.ID))
		if unit.Type != "" {
			builder.WriteString(fmt.Sprintf("- type: `%s`\n", unit.Type))
		}
		if unit.Resolution != "" {
			builder.WriteString(fmt.Sprintf("- resolution: `%s`\n", unit.Resolution))
		}
		if unit.Refines != "" {
			builder.WriteString(fmt.Sprintf("- refines: `%s`\n", unit.Refines))
		}
		if len(unit.With) > 0 {
			var with []string
			for _, rel := range unit.With {
				with = append(with, "`"+rel.ID+"`")
			}
			sort.Strings(with)
			builder.WriteString("- with: " + strings.Join(with, ", ") + "\n")
		}
		if unit.Context != "" {
			builder.WriteString("\n")
			builder.WriteString(unit.Context)
			builder.WriteString("\n")
		}
		builder.WriteString("\n")
	}
	if len(p.Links) > 0 {
		builder.WriteString("## Links\n\n")
		for _, link := range p.Links {
			builder.WriteString(fmt.Sprintf("- `%s` %s\n", link.Owner, link.Path))
			builder.WriteString(fmt.Sprintf("  - role: `%s`\n", link.Role))
			builder.WriteString(fmt.Sprintf("  - kind: `%s`\n", link.Kind))
			builder.WriteString(fmt.Sprintf("  - status: `%s`\n", link.Status))
		}
		builder.WriteString("\n")
	}
	if len(p.Warnings) > 0 {
		builder.WriteString("## Warnings\n\n")
		for _, warning := range p.Warnings {
			builder.WriteString(fmt.Sprintf("- `%s`: %s\n", warning.Code, warning.Message))
		}
	}
	return builder.String()
}

func (r ImpactResult) Markdown() string {
	var builder strings.Builder
	builder.WriteString("# GSP Impact\n\n")
	builder.WriteString(fmt.Sprintf("- Entry: `%s`\n", r.Entry))
	builder.WriteString(fmt.Sprintf("- Direct affected: `%d`\n", r.Summary.DirectCount))
	builder.WriteString(fmt.Sprintf("- Indirect affected: `%d`\n", r.Summary.IndirectCount))
	builder.WriteString(fmt.Sprintf("- Max depth: `%d`\n", r.Summary.MaxDepth))
	writeImpactSection(&builder, "Direct", r.Direct)
	writeImpactSection(&builder, "Indirect", r.Indirect)
	if len(r.Warnings) > 0 {
		builder.WriteString("## Warnings\n\n")
		for _, warning := range r.Warnings {
			builder.WriteString(fmt.Sprintf("- `%s`: %s\n", warning.Code, warning.Message))
		}
	}
	return builder.String()
}

func writeImpactSection(builder *strings.Builder, title string, entries []ImpactEntry) {
	builder.WriteString("\n## " + title + "\n\n")
	if len(entries) == 0 {
		builder.WriteString("None.\n")
		return
	}
	for _, entry := range entries {
		label := entry.Title
		if label == "" {
			label = entry.ID
		}
		builder.WriteString(fmt.Sprintf("- `%s` %s", entry.ID, label))
		if entry.Kind != "" || entry.Via != "" {
			builder.WriteString(fmt.Sprintf(" via `%s` `%s`", entry.Kind, entry.Via))
		}
		if entry.Type != "" {
			builder.WriteString(fmt.Sprintf(" type `%s`", entry.Type))
		}
		if entry.Resolution != "" {
			builder.WriteString(fmt.Sprintf(" resolution `%s`", entry.Resolution))
		}
		builder.WriteString("\n")
	}
}

func (u Unit) DisplayTitle() string {
	if strings.TrimSpace(u.Title) != "" {
		return u.Title
	}
	return u.ID
}