// Package doctor reports module convergence and pinned-tool version drift.
package doctor

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"regexp"
	"strings"

	"gitlab.hive-brain.de/MDietermann/Archduino/internal/config"
	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
	"gitlab.hive-brain.de/MDietermann/Archduino/internal/platform"
)

// Run inspects every module in the registry plus pinned tool versions and
// writes a human-readable report to w. Returns 0 when everything is
// converged with no drift; 1 otherwise. Never panics on module errors.
func Run(ctx context.Context, cfg config.Config, reg *module.Registry, runner platform.Runner, w io.Writer) int {
	var converged, pending, errs, drift int

	for _, m := range reg.All() {
		id := m.Meta().ID
		st, err := m.Detect(ctx)
		if err != nil {
			fmt.Fprintf(w, "[!] %s — detect failed: %v\n", id, err)
			errs++
			continue
		}
		pl, err := m.Plan(ctx, st)
		if err != nil {
			fmt.Fprintf(w, "[!] %s — plan failed: %v\n", id, err)
			errs++
			continue
		}
		if pl.IsEmpty() {
			fmt.Fprintf(w, "[✓] %s\n", id)
			converged++
		} else {
			fmt.Fprintf(w, "[✗] %s (%d actions pending)\n", id, len(pl.Actions))
			pending++
		}
	}

	drift += checkArduinoCLI(ctx, runner, cfg.ArduinoCLI.Version, w)
	drift += checkWokwiCLI(ctx, runner, cfg.Renode.WokwiVersion, w)

	fmt.Fprintf(w, "\n%d converged, %d need-install, %d drift, %d errors\n", converged, pending, drift, errs)

	if pending > 0 || drift > 0 || errs > 0 {
		return 1
	}
	return 0
}

type arduinoCLIVersion struct {
	VersionString string `json:"VersionString"`
}

func checkArduinoCLI(ctx context.Context, runner platform.Runner, want string, w io.Writer) int {
	if want == "" {
		return 0
	}
	out, err := runner.Output(ctx, "arduino-cli", "version", "--format", "json")
	if err != nil {
		return 0 // not installed → silent skip
	}
	var v arduinoCLIVersion
	if err := json.Unmarshal(out, &v); err != nil || v.VersionString == "" {
		fmt.Fprintf(w, "[!] arduino-cli — version parse failed\n")
		return 1
	}
	if v.VersionString != want {
		fmt.Fprintf(w, "[!] arduino-cli drift: got %s, want %s\n", v.VersionString, want)
		return 1
	}
	fmt.Fprintf(w, "[✓] arduino-cli %s\n", v.VersionString)
	return 0
}

var wokwiVersionRE = regexp.MustCompile(`v?(\d+\.\d+\.\d+)`)

func checkWokwiCLI(ctx context.Context, runner platform.Runner, want string, w io.Writer) int {
	if want == "" {
		return 0
	}
	out, err := runner.Output(ctx, "wokwi-cli", "--version")
	if err != nil {
		return 0
	}
	m := wokwiVersionRE.FindStringSubmatch(strings.TrimSpace(string(out)))
	if len(m) < 2 {
		fmt.Fprintf(w, "[!] wokwi-cli — version parse failed\n")
		return 1
	}
	got := m[1]
	if got != want {
		fmt.Fprintf(w, "[!] wokwi-cli drift: got %s, want %s\n", got, want)
		return 1
	}
	fmt.Fprintf(w, "[✓] wokwi-cli %s\n", got)
	return 0
}