package atlas

import (
	"encoding/json"
	"fmt"
)

// Host is a substrate machine/entry (koala, iguana, …).
type Host struct {
	Name string `json:"n"`
	Spec string `json:"k"`
}

// Node is a card within a stage. Plain is the jargon-free default text; Desc is
// the technical detail shown on demand.
type Node struct {
	Title      string   `json:"t"`
	PlainTitle string   `json:"plain_t,omitempty"`
	Plain      string   `json:"plain,omitempty"`
	Desc       string   `json:"d,omitempty"`
	Pill       string   `json:"pill,omitempty"`
	Cls        string   `json:"cls,omitempty"`
	Tags       []string `json:"tags,omitempty"`
	Risk       bool     `json:"risk,omitempty"`
	Gate       bool     `json:"gate,omitempty"`
	URL        string   `json:"url,omitempty"`
}

// Stage is one column of the pipeline. PlainTitle/Plain are the plain-language
// default layer; Title/Path/Nodes[].Desc are the technical layer. TransLabel/
// Trans annotate the outgoing transition (the arrow to the next stage): what
// moves work forward and what must be true to advance. When Generate is set,
// Nodes are derived from a live source at Build time.
type Stage struct {
	No         string `json:"no"`
	Short      string `json:"short,omitempty"`
	Title      string `json:"title"`
	PlainTitle string `json:"plain_title,omitempty"`
	Plain      string `json:"plain,omitempty"`
	Path       string `json:"path,omitempty"`
	Cls        string `json:"cls,omitempty"`
	Generate   string `json:"generate,omitempty"`
	TransLabel string `json:"trans_label,omitempty"`
	Trans      string `json:"trans,omitempty"`
	Nodes      []Node `json:"nodes"`
}

// Atlas is the full data model the frontend renders.
type Atlas struct {
	Version   string   `json:"version,omitempty"`
	Substrate []Host   `json:"substrate"`
	NS        string   `json:"ns,omitempty"`
	Timeline  []RunDot `json:"timeline,omitempty"`
	Stages    []Stage  `json:"stages"`
}

// Build unmarshals the authored atlas JSON and overlays generated facts from
// real sources, so sourced parts can't drift. Currently: any stage marked
// `"generate":"ci-jobs"` gets its Nodes replaced by the workflow's job list.
func Build(atlasJSON, workflow []byte) (Atlas, error) {
	var a Atlas
	if err := json.Unmarshal(atlasJSON, &a); err != nil {
		return Atlas{}, fmt.Errorf("parse atlas data: %w", err)
	}
	for i := range a.Stages {
		if a.Stages[i].Generate != "ci-jobs" {
			continue
		}
		jobs, err := JobsFromWorkflow(workflow)
		if err != nil || len(jobs) == 0 {
			continue // no CI job list available — keep the authored plain placeholder
		}
		nodes := make([]Node, 0, len(jobs))
		for _, j := range jobs {
			nodes = append(nodes, Node{Title: j, Plain: "An automated check that must pass."})
		}
		a.Stages[i].Nodes = nodes
	}
	return a, nil
}