// ingestion/internal/pipeline/build.go
package pipeline

import (
	"fmt"
	"strings"

	"github.com/mathiasbq/hyperguild/ingestion/internal/wiki"
)

// BuildPages converts RawPages from the LLM into wiki.Pages with computed slugs,
// paths, and YAML frontmatter. sourceSlug is the slug of the source being ingested
// (derived from the filename, not the LLM title).
func BuildPages(rawPages []RawPage, sourceSlug, date string) []wiki.Page {
	out := make([]wiki.Page, 0, len(rawPages))
	for _, rp := range rawPages {
		out = append(out, buildPage(rp, sourceSlug, date))
	}
	return out
}

func buildPage(rp RawPage, sourceSlug, date string) wiki.Page {
	var slug, dir string
	switch rp.Type {
	case "source":
		slug = sourceSlug
		dir = "wiki/sources"
	case "concept":
		slug = wiki.Slug(rp.Title)
		dir = "wiki/concepts"
	case "entity":
		slug = wiki.Slug(rp.Title)
		dir = "wiki/entities"
	default:
		slug = wiki.Slug(rp.Title)
		dir = "wiki/" + rp.Type
	}

	path := dir + "/" + slug + ".md"
	fm := buildFrontmatter(rp, date)

	return wiki.Page{
		Path:    path,
		Content: fm + "\n" + rp.Content,
	}
}

func buildFrontmatter(rp RawPage, date string) string {
	var sb strings.Builder
	sb.WriteString("---\n")
	fmt.Fprintf(&sb, "title: %s\n", yamlScalar(rp.Title))

	switch rp.Type {
	case "source":
		subtype := rp.Subtype
		if subtype == "" {
			subtype = "article"
		}
		fmt.Fprintf(&sb, "type: %s\n", yamlScalar(subtype))
		if rp.Domain != "" {
			fmt.Fprintf(&sb, "domain: %s\n", yamlScalar(rp.Domain))
		}
		fmt.Fprintf(&sb, "date_ingested: %s\n", date)
		fmt.Fprintf(&sb, "last_updated: %s\n", date)
	case "concept":
		if rp.Domain != "" {
			fmt.Fprintf(&sb, "domain: %s\n", yamlScalar(rp.Domain))
		}
		fmt.Fprintf(&sb, "last_updated: %s\n", date)
	case "entity":
		if rp.Subtype != "" {
			fmt.Fprintf(&sb, "type: %s\n", yamlScalar(rp.Subtype))
		}
		if rp.Domain != "" {
			fmt.Fprintf(&sb, "domain: %s\n", yamlScalar(rp.Domain))
		}
		fmt.Fprintf(&sb, "last_updated: %s\n", date)
	default:
		if rp.Domain != "" {
			fmt.Fprintf(&sb, "domain: %s\n", yamlScalar(rp.Domain))
		}
		fmt.Fprintf(&sb, "last_updated: %s\n", date)
	}

	fmt.Fprintf(&sb, "aliases:\n  - %s\n", yamlScalar(rp.Title))
	sb.WriteString("---\n")
	return sb.String()
}

func yamlScalar(s string) string {
	return "'" + strings.ReplaceAll(s, "'", "''") + "'"
}