package main

import (
	"fmt"
	"image"
	"log"
	"os"
	"path/filepath"
	"strings"
	"time"
)

// InstanceData holds the serializable state for a saved enclosure instance.
type InstanceData struct {
	ID        string    `json:"id"`
	Name      string    `json:"name,omitempty"`
	CreatedAt time.Time `json:"createdAt"`

	// Source files (basenames relative to the project directory)
	GerberFiles map[string]string `json:"gerberFiles"`
	DrillPath   string            `json:"drillPath,omitempty"`
	NPTHPath    string            `json:"npthPath,omitempty"`

	// Discovered layer filenames (keys into GerberFiles)
	EdgeCutsFile   string `json:"edgeCutsFile"`
	CourtyardFile  string `json:"courtyardFile,omitempty"`
	SoldermaskFile string `json:"soldermaskFile,omitempty"`
	FabFile        string `json:"fabFile,omitempty"`

	// Configuration
	Config  EnclosureConfig `json:"config"`
	Exports []string        `json:"exports"`

	// Board display info
	BoardW      float64 `json:"boardW"`
	BoardH      float64 `json:"boardH"`
	ProjectName string  `json:"projectName,omitempty"`

	// Unified cutouts (new format)
	Cutouts []Cutout `json:"cutouts,omitempty"`

	// Legacy cutout fields — kept for backward compatibility when loading old projects
	SideCutouts []SideCutout `json:"sideCutouts,omitempty"`
	LidCutouts  []LidCutout  `json:"lidCutouts,omitempty"`
}

// MigrateCutouts returns the unified cutouts list, converting legacy fields if needed.
func (inst *InstanceData) MigrateCutouts() []Cutout {
	if len(inst.Cutouts) > 0 {
		return inst.Cutouts
	}
	// Migrate legacy side cutouts
	var result []Cutout
	for _, sc := range inst.SideCutouts {
		result = append(result, Cutout{
			ID:           randomID(),
			Surface:      "side",
			SideNum:      sc.Side,
			X:            sc.X,
			Y:            sc.Y,
			Width:        sc.Width,
			Height:       sc.Height,
			CornerRadius: sc.CornerRadius,
			SourceLayer:  sc.Layer,
		})
	}
	// Migrate legacy lid cutouts
	for _, lc := range inst.LidCutouts {
		surface := "top"
		if lc.Plane == "tray" {
			surface = "bottom"
		}
		result = append(result, Cutout{
			ID:      randomID(),
			Surface: surface,
			X:       lc.MinX,
			Y:       lc.MinY,
			Width:   lc.MaxX - lc.MinX,
			Height:  lc.MaxY - lc.MinY,
			IsDado:  lc.IsDado,
			Depth:   lc.Depth,
		})
	}
	return result
}

// restoreSessionFromDir rebuilds an EnclosureSession from an InstanceData,
// resolving all file paths relative to baseDir.
func restoreSessionFromDir(inst *InstanceData, baseDir string) (string, *EnclosureSession, error) {
	outlineBasename, ok := inst.GerberFiles[inst.EdgeCutsFile]
	if !ok {
		return "", nil, fmt.Errorf("edge cuts file not found: %s", inst.EdgeCutsFile)
	}
	outlinePath := filepath.Join(baseDir, outlineBasename)
	if _, err := os.Stat(outlinePath); err != nil {
		return "", nil, fmt.Errorf("source files no longer available: %v", err)
	}

	outlineGf, err := ParseGerber(outlinePath)
	if err != nil {
		return "", nil, fmt.Errorf("parse outline: %v", err)
	}

	outlineBounds := outlineGf.CalculateBounds()
	actualBoardW := outlineBounds.MaxX - outlineBounds.MinX
	actualBoardH := outlineBounds.MaxY - outlineBounds.MinY

	ecfg := inst.Config
	margin := ecfg.WallThickness + ecfg.Clearance + 5.0
	outlineBounds.MinX -= margin
	outlineBounds.MinY -= margin
	outlineBounds.MaxX += margin
	outlineBounds.MaxY += margin
	ecfg.OutlineBounds = &outlineBounds

	outlineImg := outlineGf.Render(ecfg.DPI, &outlineBounds)

	minBX, maxBX := outlineImg.Bounds().Max.X, -1
	var boardCenterY float64
	var boardCount int
	_, boardMask := ComputeWallMask(outlineImg, ecfg.WallThickness+ecfg.Clearance, ecfg.DPI/25.4)
	imgW, imgH := outlineImg.Bounds().Max.X, outlineImg.Bounds().Max.Y
	for y := 0; y < imgH; y++ {
		for x := 0; x < imgW; x++ {
			if boardMask[y*imgW+x] {
				if x < minBX {
					minBX = x
				}
				if x > maxBX {
					maxBX = x
				}
				boardCenterY += float64(y)
				boardCount++
			}
		}
	}
	if boardCount > 0 {
		boardCenterY /= float64(boardCount)
	}

	// Resolve gerber paths relative to baseDir and render ALL layers
	resolvedGerbers := make(map[string]string)
	allLayers := make(map[string]image.Image)
	allGerbers := make(map[string]*GerberFile)
	for origName, basename := range inst.GerberFiles {
		fullPath := filepath.Join(baseDir, basename)
		resolvedGerbers[origName] = fullPath
		if strings.HasSuffix(strings.ToLower(origName), ".gbrjob") {
			continue
		}
		if origName == inst.EdgeCutsFile {
			allLayers[origName] = outlineImg
			allGerbers[origName] = outlineGf
			continue
		}
		if gf, err := ParseGerber(fullPath); err == nil {
			allLayers[origName] = gf.Render(ecfg.DPI, &outlineBounds)
			allGerbers[origName] = gf
		}
	}

	var courtyardImg, soldermaskImg image.Image
	if inst.CourtyardFile != "" {
		courtyardImg = allLayers[inst.CourtyardFile]
	}
	if inst.SoldermaskFile != "" {
		soldermaskImg = allLayers[inst.SoldermaskFile]
	}
	if courtyardImg == nil && inst.FabFile != "" {
		courtyardImg = allLayers[inst.FabFile]
	}

	var drillHoles []DrillHole
	if inst.DrillPath != "" {
		if holes, err := ParseDrill(filepath.Join(baseDir, inst.DrillPath)); err == nil {
			drillHoles = append(drillHoles, holes...)
		}
	}
	if inst.NPTHPath != "" {
		if holes, err := ParseDrill(filepath.Join(baseDir, inst.NPTHPath)); err == nil {
			drillHoles = append(drillHoles, holes...)
		}
	}
	var filteredHoles []DrillHole
	for _, h := range drillHoles {
		if h.Type != DrillTypeVia {
			filteredHoles = append(filteredHoles, h)
		}
	}

	pixelToMM := 25.4 / ecfg.DPI
	sessionID := randomID()
	session := &EnclosureSession{
		Exports:        inst.Exports,
		OutlineGf:      outlineGf,
		OutlineImg:     outlineImg,
		CourtyardImg:   courtyardImg,
		SoldermaskImg:  soldermaskImg,
		DrillHoles:     filteredHoles,
		Config:         ecfg,
		OutlineBounds:  outlineBounds,
		BoardW:         actualBoardW,
		BoardH:         actualBoardH,
		TotalH:         ecfg.WallHeight + ecfg.PCBThickness + 1.0,
		MinBX:          float64(minBX)*pixelToMM + outlineBounds.MinX,
		MaxBX:          float64(maxBX)*pixelToMM + outlineBounds.MinX,
		BoardCenterY:   outlineBounds.MaxY - boardCenterY*pixelToMM,
		Sides:          ExtractBoardSidesFromMask(boardMask, imgW, imgH, pixelToMM, &outlineBounds),
		GerberFiles:    inst.GerberFiles,
		DrillPath:      inst.DrillPath,
		NPTHPath:       inst.NPTHPath,
		ProjectName:    inst.ProjectName,
		EdgeCutsFile:   inst.EdgeCutsFile,
		CourtyardFile:  inst.CourtyardFile,
		SoldermaskFile: inst.SoldermaskFile,
		FabFile:          inst.FabFile,
		EnclosureWallImg: renderEnclosureWallImage(outlineImg, ecfg),
		AllLayerImages:   allLayers,
		AllLayerGerbers:  allGerbers,
		SourceDir:        baseDir,
	}

	log.Printf("Restored session %s from %s (%s)", sessionID, baseDir, inst.ProjectName)
	return sessionID, session, nil
}